Quectel Wireless Solutions 201805EC21AU LTE Module User Manual

Quectel Wireless Solutions Company Limited LTE Module Users Manual

Users Manual

EC21 Hardware Design LTE Module Series Rev. EC21_Hardware_Design_V1.5 Date: 2017-03-05 Status: Released www.quectel.com
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 1 / 105 Our aim is to provide customers with timely and comprehensive service. For any assistance, please contact our company headquarters: Quectel Wireless Solutions Co., Ltd. 7th Floor, Hongye Building, No.1801 Hongmei Road, Xuhui District, Shanghai 200233, China Tel: +86 21 5108 6236 Email: info@quectel.com Or our local office. For more information, please visit: http://quectel.com/support/sales.htm For technical support, or to report documentation errors, please visit: http://quectel.com/support/technical.htm Or Email to: support@quectel.com GENERAL NOTES QUECTEL OFFERS THE INFORMATION AS A SERVICE TO ITS CUSTOMERS. THE INFORMATION PROVIDED IS BASED UPON CUSTOMERS’ REQUIREMENTS. QUECTEL MAKES EVERY EFFORT TO ENSURE THE QUALITY OF THE INFORMATION IT MAKES AVAILABLE. QUECTEL DOES NOT MAKE ANY WARRANTY AS TO THE INFORMATION CONTAINED HEREIN, AND DOES NOT ACCEPT ANY LIABILITY FOR ANY INJURY, LOSS OR DAMAGE OF ANY KIND INCURRED BY USE OF OR RELIANCE UPON THE INFORMATION. ALL INFORMATION SUPPLIED HEREIN IS SUBJECT TO CHANGE WITHOUT PRIOR NOTICE. COPYRIGHT THE INFORMATION CONTAINED HERE IS PROPRIETARY TECHNICAL INFORMATION OF QUECTEL WIRELESS SOLUTIONS CO., LTD. TRANSMITTING, REPRODUCTION, DISSEMINATION AND EDITING OF THIS DOCUMENT AS WELL AS UTILIZATION OF THE CONTENT ARE FORBIDDEN WITHOUT PERMISSION. OFFENDERS WILL BE HELD LIABLE FOR PAYMENT OF DAMAGES. ALL RIGHTS ARE RESERVED IN THE EVENT OF A PATENT GRANT OR REGISTRATION OF A UTILITY MODEL OR DESIGN. Copyright © Quectel Wireless Solutions Co., Ltd. 2018. All rights reserved.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 2 / 105 About the Document History Revision Date Author Description 1.0 2016-04-15 Yeoman CHEN Initial 1.1 2016-09-22 Yeoman CHEN/ Frank WANG/ Lyndon LIU 1. Updated frequency bands in Table 1. 2. Updated transmitting power, supported maximum baud rate of main UART, supported internet protocols, supported USB drivers of USB interface, and temperature range in Table 2. 3. Updated timing of turning on module in Figure 12. 4. Updated timing of turning off module in Figure 13. 5. Updated timing of resetting module in Figure 16. 6. Updated main UART supports baud rate in Chapter 3.11. 7. Added notes for ADC interface in Chapter 3.13. 8. Updated GNSS Performance in Table 21. 9. Updated operating frequencies of module in Table 23. 10. Added current consumption in Chapter 6.4. 11. Updated RF output power in Chapter 6.5. 12. Added RF receiving sensitivity in Chapter 6.6. 1.2 2016-11-04 Lyndon LIU/ Michael ZHANG 1. Added SGMII and WLAN interfaces in Table 2. 2. Updated function diagram in Figure 1. 3. Updated pin assignment (Top View) in Figure 2. 4. Added description of SGMII and WLAN interfaces in Table 4. 5. Added SGMII interface in Chapter 3.17. 6. Added WLAN interface in Chapter 3.18. 7. Added USB_BOOT interface in Chapter 3.19. 8. Added reference design of RF layout in Chapter 5.1.4. 9. Added current consumption of EC21-V in Chapter
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 3 / 105 6.4. 10. Added note about SIMO in Chapter 6.6. 1.3 2017-01-24 Lyndon LIU/ Rex WANG 1. Updated frequency bands in Table 1. 2. Updated function diagram in Figure 1. 3. Updated pin assignment (top view) in Figure 2. 4. Added BT interface in Chapter 3.18.2. 5. Updated reference circuit of wireless connectivity interfaces with FC20 module in Figure 29. 6. Updated GNSS performance in Table 24. 7. Updated module operating frequencies in Table 26. 8. Added EC21-AUV current consumption in Table 38. 9. Updated EC21-A conducted RF receiving sensitivity of in Table 42. 10. Added EC21-J conducted RF receiving sensitivity in Table 48. 1.4 2017-03-01 Geely YANG Deleted the LTE band TDD B41 of EC21-CT 1.5 2018-03-05 Annice ZHANG/ Lyndon LIU/ Frank WANG 1. Updated functional diagram in Figure 1. 2. Updated frequency bands in Table 1. 3. Updated UMTS and GSM features in Table 2. 4. Updated description of pin 40/136/137/138. 5. Updated PWRKEY pulled down time to 500ms in chapter 3.7.1 and reference circuit in Figure 10. 6. Updated reference circuit of (U)SIM interface in Figure 17&18. 7. Updated reference circuit of USB interface in Figure 19. 8. Updated PCM mode in Chapter 3.12. 9. Updated USB_BOOT reference circuit in Chapter 3.20. 10. Added SD card interface in Chapter 3.13. 11. Updated module operating frequencies in Table 26. 12. Updated EC21 series modules current consumption in Chapter 6.5. 13. Updated EC21 series modules conducted RF receiving sensitivity in Chapter 6.6. 14. Added thermal consideration description in Chapter 6.8. 15. Updated dimension tolerance information in Chapter 7. 16. Added storage temperature range in Table 2 and Chapter 6.3. 17. Updated RF output power in Table 42. 18. Updated antenna requirements in Table 29.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 4 / 105 19. Updated GPRS multi-slot classes in Table 55. 20. Updated storage information in Chapter 8.1
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 5 / 105 Contents About the Document ................................................................................................................................ 2Contents .................................................................................................................................................... 5Table Index ............................................................................................................................................... 8Figure Index ............................................................................................................................................ 101Introduction ..................................................................................................................................... 121.1.Safety Information ................................................................................................................. 131.2.FCC Statement ..................................................................................................................... 142Product Concept ............................................................................................................................. 162.1.General Description .............................................................................................................. 162.2.Key Features ......................................................................................................................... 172.3.Functional Diagram ............................................................................................................... 202.4.Evaluation Board ................................................................................................................... 203Application Interfaces ..................................................................................................................... 213.1.General Description .............................................................................................................. 213.2.Pin Assignment ..................................................................................................................... 223.3.Pin Description ...................................................................................................................... 233.4.Operating Modes .................................................................................................................. 343.5.Power Saving ........................................................................................................................ 353.5.1.Sleep Mode.................................................................................................................. 353.5.1.1.UART Application ............................................................................................... 353.5.1.2.USB Application with USB Remote Wakeup Function ....................................... 363.5.1.3.USB Application with USB Suspend/Resume and RI Function .......................... 373.5.1.4.USB Application without USB Suspend Function ............................................... 373.5.2.Airplane Mode .............................................................................................................. 383.6.Power Supply ........................................................................................................................ 393.6.1.Power Supply Pins ....................................................................................................... 393.6.2.Decrease Voltage Drop ................................................................................................ 393.6.3.Reference Design for Power Supply ............................................................................ 403.6.4.Monitor the Power Supply ............................................................................................ 413.7.Turn on and off Scenarios ..................................................................................................... 413.7.1.Turn on Module Using the PWRKEY ........................................................................... 413.7.2.Turn off Module ............................................................................................................ 433.7.2.1.Turn off Module Using the PWRKEY Pin ........................................................... 433.7.2.2.Turn off Module Using AT Command ................................................................. 443.8.Reset the Module .................................................................................................................. 443.9.(U)SIM Interface .................................................................................................................... 463.10.USB Interface ........................................................................................................................ 483.11.UART Interfaces .................................................................................................................... 50
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 6 / 105 3.12.PCM and I2C Interfaces ........................................................................................................ 523.13.SD Card Interface ................................................................................................................. 543.14.ADC Interfaces ...................................................................................................................... 573.15.Network Status Indication ...................................................................................................... 573.16.STATUS ................................................................................................................................ 593.17.Behaviors of RI ..................................................................................................................... 593.18.SGMII Interface ..................................................................................................................... 603.19.Wireless Connectivity Interfaces ........................................................................................... 623.19.1.WLAN Interface ........................................................................................................... 653.19.2.BT Interface* ................................................................................................................ 653.20.USB_BOOT Interface ............................................................................................................ 664GNSS Receiver ................................................................................................................................ 674.1.General Description .............................................................................................................. 674.2.GNSS Performance .............................................................................................................. 674.3.Layout Guidelines ................................................................................................................. 685Antenna Interfaces .......................................................................................................................... 695.1.Main/Rx-diversity Antenna Interfaces.................................................................................... 695.1.1.Pin Definition ................................................................................................................ 695.1.2.Operating Frequency ................................................................................................... 695.1.3.Reference Design of RF Antenna Interface ................................................................. 705.1.4.Reference Design of RF Layout ................................................................................... 715.2.GNSS Antenna Interface ....................................................................................................... 735.3.Antenna Installation ............................................................................................................... 745.3.1.Antenna Requirement .................................................................................................. 745.3.2.Recommended RF Connector for Antenna Installation ................................................ 756Electrical, Reliability and Radio Characteristics .......................................................................... 776.1.Absolute Maximum Ratings .................................................................................................. 776.2.Power Supply Ratings ........................................................................................................... 786.3.Operation and Storage Temperatures ................................................................................... 786.4.Current Consumption ............................................................................................................ 796.5.RF Output Power .................................................................................................................. 856.6.RF Receiving Sensitivity ....................................................................................................... 866.7.Electrostatic Discharge ......................................................................................................... 906.8.Thermal Consideration .......................................................................................................... 907Mechanical Dimensions.................................................................................................................. 937.1.Mechanical Dimensions of the Module.................................................................................. 937.2.Recommended Footprint ....................................................................................................... 957.3.Design Effect Drawings of the Module .................................................................................. 968Storage, Manufacturing and Packaging ........................................................................................ 978.1.Storage.................................................................................................................................. 978.2.Manufacturing and Soldering ................................................................................................ 988.3.Packaging ............................................................................................................................. 99
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 7 / 105 9Appendix A References ................................................................................................................ 10010Appendix B GPRS Coding Schemes ........................................................................................... 10411Appendix C GPRS Multi-slot Classes .......................................................................................... 10512Appendix D EDGE Modulation and Coding Schemes ................................................................ 107
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 8 / 105 Table Index TABLE 1: FREQUENCY BANDS OF EC21 SERIES MODULE ........................................................................ 16 TABLE 2: KEY FEATURES OF EC21 MODULE ............................................................................................... 17 TABLE 3: I/O PARAMETERS DEFINITION ....................................................................................................... 23 TABLE 4: PIN DESCRIPTION ........................................................................................................................... 23 TABLE 5: OVERVIEW OF OPERATING MODES ............................................................................................. 34 TABLE 6: VBAT AND GND PINS ....................................................................................................................... 39 TABLE 7: PIN DEFINITION OF PWRKEY ........................................................................................................ 41 TABLE 8: PIN DEFINITION OF RESET_N ....................................................................................................... 45 TABLE 9: PIN DEFINITION OF THE (U)SIM INTERFACE ............................................................................... 46 TABLE 10: PIN DESCRIPTION OF USB INTERFACE ..................................................................................... 48 TABLE 11: PIN DEFINITION OF MAIN UART INTERFACE ............................................................................. 50 TABLE 12: PIN DEFINITION OF DEBUG UART INTERFACE ......................................................................... 50 TABLE 13: LOGIC LEVELS OF DIGITAL I/O .................................................................................................... 51 TABLE 14: PIN DEFINITION OF PCM AND I2C INTERFACES ....................................................................... 53 TABLE 15: PIN DEFINITION OF SD CARD INTERFACE ................................................................................ 55 TABLE 16: PIN DEFINITION OF ADC INTERFACES ....................................................................................... 57 TABLE 17: CHARACTERISTIC OF ADC .......................................................................................................... 57 TABLE 18: PIN DEFINITION OF NETWORK CONNECTION STATUS/ACTIVITY INDICATOR ...................... 58 TABLE 19: WORKING STATE OF NETWORK CONNECTION STATUS/ACTIVITY INDICATOR ................... 58 TABLE 20: PIN DEFINITION OF STATUS ........................................................................................................ 59 TABLE 21: BEHAVIOR OF RI ............................................................................................................................ 60 TABLE 22: PIN DEFINITION OF THE SGMII INTERFACE .............................................................................. 60 TABLE 23: PIN DEFINITION OF WIRELESS CONNECTIVITY INTERFACES ................................................ 63 TABLE 24: PIN DEFINITION OF USB_BOOT INTERFACE ............................................................................. 66 TABLE 25: GNSS PERFORMANCE ................................................................................................................. 67 TABLE 26: PIN DEFINITION OF RF ANTENNAS ............................................................................................. 69 TABLE 27: MODULE OPERATING FREQUENCIES ........................................................................................ 69 TABLE 28: PIN DEFINITION OF GNSS ANTENNA INTERFACE ..................................................................... 73 TABLE 29: GNSS FREQUENCY ....................................................................................................................... 73 TABLE 30: ANTENNA REQUIREMENTS .......................................................................................................... 74 TABLE 31: ABSOLUTE MAXIMUM RATINGS .................................................................................................. 77 TABLE 32: POWER SUPPLY RATINGS ........................................................................................................... 78 TABLE 33: OPERATION AND STORAGE TEMPERATURES .......................................................................... 78 TABLE 34: EC21-E CURRENT CONSUMPTION ............................................................................................. 79 TABLE 35: EC21-A CURRENT CONSUMPTION ............................................................................................. 81 TABLE 36: EC21-V CURRENT CONSUMPTION ............................................................................................. 82 TABLE 37: EC21-AUT CURRENT CONSUMPTION ........................................................................................ 82 TABLE 38: EC21-AUV CURRENT CONSUMPTION ........................................................................................ 83 TABLE 39: EC21-J CURRENT CONSUMPTION .............................................................................................. 84 TABLE 40: EC21-KL CURRENT CONSUMPTION ........................................................................................... 85 TABLE 41: GNSS CURRENT CONSUMPTION OF EC21 SERIES MODULE ................................................. 85
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 9 / 105 TABLE 42: RF OUTPUT POWER ..................................................................................................................... 86 TABLE 43: EC21-E CONDUCTED RF RECEIVING SENSITIVITY .................................................................. 86 TABLE 44: EC21-A CONDUCTED RF RECEIVING SENSITIVITY .................................................................. 87 TABLE 45: EC21-V CONDUCTED RF RECEIVING SENSITIVITY .................................................................. 87 TABLE 46: EC21-AUT CONDUCTED RF RECEIVING SENSITIVITY ............................................................. 87 TABLE 47: EC21-KL CONDUCTED RF RECEIVING SENSITIVITY ................................................................ 88 TABLE 48: EC21-J CONDUCTED RF RECEIVING SENSITIVITY................................................................... 88 TABLE 49: EC21-AUV CONDUCTED RF RECEIVING SENSITIVITY ............................................................. 88 TABLE 50: EC21-AU CONDUCTED RF RECEIVING SENSITIVITY ............................................................... 89 TABLE 51: ELECTROSTATIC DISCHARGE CHARACTERISTICS ................................................................. 90 TABLE 52: RELATED DOCUMENTS .............................................................................................................. 100 TABLE 53: TERMS AND ABBREVIATIONS .................................................................................................... 100 TABLE 54: DESCRIPTION OF DIFFERENT CODING SCHEMES ................................................................ 104 TABLE 55: GPRS MULTI-SLOT CLASSES .................................................................................................... 105 TABLE 56: EDGE MODULATION AND CODING SCHEMES ......................................................................... 107
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 10 / 105 Figure Index FIGURE 1: FUNCTIONAL DIAGRAM ............................................................................................................... 20 FIGURE 2: PIN ASSIGNMENT (TOP VIEW) .................................................................................................... 22 FIGURE 3: SLEEP MODE APPLICATION VIA UART ....................................................................................... 35 FIGURE 4: SLEEP MODE APPLICATION WITH USB REMOTE WAKEUP .................................................... 36 FIGURE 5: SLEEP MODE APPLICATION WITH RI ......................................................................................... 37 FIGURE 6: SLEEP MODE APPLICATION WITHOUT SUSPEND FUNCTION ................................................ 38 FIGURE 7: POWER SUPPLY LIMITS DURING BURST TRANSMISSION ...................................................... 39 FIGURE 8: STAR STRUCTURE OF THE POWER SUPPLY ............................................................................ 40 FIGURE 9: REFERENCE CIRCUIT OF POWER SUPPLY .............................................................................. 41 FIGURE 10: TURN ON THE MODULE BY USING DRIVING CIRCUIT ........................................................... 42 FIGURE 11: TURN ON THE MODULE BY USING BUTTON ........................................................................... 42 FIGURE 12: TIMING OF TURNING ON MODULE ........................................................................................... 43 FIGURE 13: TIMING OF TURNING OFF MODULE ......................................................................................... 44 FIGURE 14: REFERENCE CIRCUIT OF RESET_N BY USING DRIVING CIRCUIT ...................................... 45 FIGURE 15: REFERENCE CIRCUIT OF RESET_N BY USING BUTTON ...................................................... 45 FIGURE 16: TIMING OF RESETTING MODULE ............................................................................................. 46 FIGURE 17: REFERENCE CIRCUIT OF (U)SIM INTERFACE WITH AN 8-PIN (U)SIM CARD CONNECTOR ................................................................................................................................................................... 47 FIGURE 18: REFERENCE CIRCUIT OF (U)SIM INTERFACE WITH A 6-PIN (U)SIM CARD CONNECTOR . 47 FIGURE 19: REFERENCE CIRCUIT OF USB APPLICATION ......................................................................... 49 FIGURE 20: REFERENCE CIRCUIT WITH TRANSLATOR CHIP ................................................................... 51 FIGURE 21: REFERENCE CIRCUIT WITH TRANSISTOR CIRCUIT .............................................................. 52 FIGURE 22: PRIMARY MODE TIMING ............................................................................................................ 53 FIGURE 23: AUXILIARY MODE TIMING .......................................................................................................... 53 FIGURE 24: REFERENCE CIRCUIT OF PCM APPLICATION WITH AUDIO CODEC .................................... 54 FIGURE 25: REFERENCE CIRCUIT OF SD CARD ......................................................................................... 56 FIGURE 26: REFERENCE CIRCUIT OF THE NETWORK INDICATOR .......................................................... 58 FIGURE 27: REFERENCE CIRCUITS OF STATUS ......................................................................................... 59 FIGURE 28: SIMPLIFIED BLOCK DIAGRAM FOR ETHERNET APPLICATION ............................................. 61 FIGURE 29: REFERENCE CIRCUIT OF SGMII INTERFACE WITH PHY AR8033 APPLICATION ................. 62 FIGURE 30: REFERENCE CIRCUIT OF WIRELESS CONNECTIVITY INTERFACES WITH FC20 MODULE ................................................................................................................................................................... 64 FIGURE 31: REFERENCE CIRCUIT OF USB_BOOT INTERFACE ................................................................ 66 FIGURE 32: REFERENCE CIRCUIT OF RF ANTENNA INTERFACE ............................................................. 71 FIGURE 33: MICROSTRIP LINE DESIGN ON A 2-LAYER PCB ...................................................................... 71 FIGURE 34: COPLANAR WAVEGUIDE LINE DESIGN ON A 2-LAYER PCB .................................................. 72 FIGURE 35: COPLANAR WAVEGUIDE LINE DESIGN ON A 4-LAYER PCB (LAYER 3 AS REFERENCE GROUND) .................................................................................................................................................. 72 FIGURE 36: COPLANAR WAVEGUIDE LINE DESIGN ON A 4-LAYER PCB (LAYER 4 AS REFERENCE GROUND) .................................................................................................................................................. 72 FIGURE 37: REFERENCE CIRCUIT OF GNSS ANTENNA ............................................................................. 74
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 11 / 105 FIGURE 38: DIMENSIONS OF THE U.FL-R-SMT CONNECTOR (UNIT: MM) ................................................ 75 FIGURE 39: MECHANICALS OF U.FL-LP CONNECTORS ............................................................................. 76 FIGURE 40: SPACE FACTOR OF MATED CONNECTOR (UNIT: MM) ........................................................... 76 FIGURE 41: REFERENCED HEATSINK DESIGN (HEATSINK AT THE TOP OF THE MODULE) .................. 91 FIGURE 42: REFERENCED HEATSINK DESIGN (HEATSINK AT THE BOTTOM OF CUSTOMERS’ PCB) . 91 FIGURE 43: MODULE TOP AND SIDE DIMENSIONS ..................................................................................... 93 FIGURE 44: MODULE BOTTOM DIMENSIONS (BOTTOM VIEW) ................................................................. 94 FIGURE 45: RECOMMENDED FOOTPRINT (TOP VIEW) .............................................................................. 95 FIGURE 46: TOP VIEW OF THE MODULE ...................................................................................................... 96 FIGURE 47: BOTTOM VIEW OF THE MODULE .............................................................................................. 96 FIGURE 48: REFLOW SOLDERING THERMAL PROFILE .............................................................................. 98 FIGURE 49: TAPE AND REEL SPECIFICATIONS ........................................................................................... 99
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 12 / 105 1 Introduction This document defines the EC21 module and describes its air interface and hardware interface which are connected with customers’ applications. This document can help customers quickly understand module interface specifications, electrical and mechanical details, as well as other related information of EC21 module. Associated with application note and user guide, customers can use EC21 module to design and set up mobile applications easily.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 13 / 105 1.1. Safety Information The following safety precautions must be observed during all phases of the operation, such as usage, service or repair of any cellular terminal or mobile incorporating EC21 module. Manufacturers of the cellular terminal should send the following safety information to users and operating personnel, and incorporate these guidelines into all manuals supplied with the product. If not so, Quectel assumes no liability for the customers’ failure to comply with these precautions. Full attention must be given to driving at all times in order to reduce the risk of an accident. Using a mobile while driving (even with a handsfree kit) causes distraction and can lead to an accident. You must comply with laws and regulations restricting the use of wireless devices while driving. Switch off the cellular terminal or mobile before boarding an aircraft. Make sure it is switched off. The operation of wireless appliances in an aircraft is forbidden, so as to prevent interference with communication systems. Consult the airline staff about the use of wireless devices on boarding the aircraft, if your device offers an Airplane Mode which must be enabled prior to boarding an aircraft. Switch off your wireless device when in hospitals,clinics or other health care facilities. These requests are desinged to prevent possible interference with sensitive medical equipment. Cellular terminals or mobiles operating over radio frequency signal and cellular network cannot be guaranteed to connect in all conditions, for example no mobile fee or with an invalid (U)SIM card. While you are in this condition and need emergent help, please remember using emergency call. In order to make or receive a call, the cellular terminal or mobile must be switched on and in a service area with adequate cellular signal strength. Your cellular terminal or mobile contains a transmitter and receiver. When it is ON, it receives and transmits radio frequency energy. RF interference can occur if it is used close to TV set, radio, computer or other electric equipment. In locations with potentially explosive atmospheres, obey all posted signs to turn off wireless devices such as your phone or other cellular terminals. Areas with potentially explosive atmospheres include fuelling areas, below decks on boats, fuel or chemical transfer or storage facilities, areas where the air contains chemicals or particles such as grain, dust or metal powders, etc.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 14 / 105 1.2. FCC Statement According to the definition of mobile and fixed device is described in Part 2.1091(b), this device is a mobile device. And the following conditions must be met: 1. This Modular Approval is limited to OEM installation for mobile and fixed applications only. The antenna installation and operating configurations of this transmitter, including any applicable source-based time- averaging duty factor, antenna gain and cable loss must satisfy MPE categorical Exclusion Requirements of 2.1091. 2. The EUT is a mobile device; maintain at least a 20 cm separation between the EUT and the user’s body and must not transmit simultaneously with any other antenna or transmitter. 3.A label with the following statements must be attached to the host end product: This device contains FCC ID: XMR201805EC21AU. 4.To comply with FCC regulations limiting both maximum RF output power and human exposure to RF radiation, maximum antenna gain (including cable loss) must not exceed 4dBi 5. This module must not transmit simultaneously with any other antenna or transmitter 6. The host end product must include a user manual that clearly defines operating requirements and conditions that must be observed to ensure compliance with current FCC RF exposure guidelines. For portable devices, in addition to the conditions 3 through 6 described above, a separate approval is required to satisfy the SAR requirements of FCC Part 2.1093 If the device is used for other equipment that separate approval is required for all other operating configurations, including portable configurations with respect to 2.1093 and different antenna configurations. For this device, OEM integrators must be provided with labeling instructions of finished products. Please refer to KDB784748 D01 v07, section 8. Page 6/7 last two paragraphs: A certified modular has the option to use a permanently affixed label, or an electronic label. For a permanently affixed label, the module must be labelled withan FCC ID - Section 2.926 (see 2.2 Certification (labelling requirements) above). The OEM manual must provide clear instructions explaining to the OEM the labelling requirements,options and OEM user manual instructions that are required (see next paragraph). For a host using a certified modular with a standard fixed label, if (1) the module’s FCC ID is notvisible when installed in the host, or (2) if the host is marketed so that end users do not havestraightforward commonly used methods for access to remove the module so that the FCC ID ofthe module is visible; then an additional permanent label referring to the enclosed module:“Contains Transmitter Module FCC ID:XMR201805EC21AU” or “Contains FCC ID: XMR201805EC21AU” mustbe used. The host OEM user manual must also contain clear instructions on how end users can find and/or access the module and the FCC ID. The final host / module combination may also need to be evaluated against the FCC Part 15B criteria for unintentional radiators in order to be properly authorized for operation as a Part 15 digital device. The user’s manual or instruction manual for an intentional or unintentional radiator shall caution the user that changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment. In cases where the manual is provided only in a form other than paper, such as on a computer disk or over the Internet, the information required by this section may be
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 15 / 105 included in the manual in that alternative form, provided the user can reasonably be expected to have the capability to access information in that form. This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Changes or modifications not expressly approved by the manufacturer could void the user’s authority to operate the equipment. To ensure compliance with all non-transmitter functions the host manufacturer is responsible for ensuring compliance with the module(s) installed and fully operational. For example, if a host was previously authorized as an unintentional radiator under the Declaration of Conformity procedure without a transmitter certified module and a module is added, the host manufacturer is responsible for ensuring that the after the module is installed and operational the host continues to be compliant with the Part 15B unintentional radiator requirements.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 16 / 105 2 Product Concept 2.1. General Description EC21 is a series of LTE-FDD/LTE-TDD/WCDMA/GSM wireless communication module with receive diversity. It provides data connectivity on LTE-FDD, LTE-TDD, DC-HSDPA, HSPA+, HSDPA, HSUPA, WCDMA, EDGE and GPRS networks. It also provides GNSS1) and voice functionality2) for customers’ specific applications. EC21 contains nine variants: EC21-E, EC21-A, EC21-V, EC21-AU, EC21-AUT, EC21-AUV, EC21-J, EC21-KL and EC20-CEL. Customers can choose a dedicated type based on the region or operator. The following table shows the frequency bands of EC21 series module. Table 1: Frequency Bands of EC21 Series Module Modules2) LTE Bands UMTS Bands GSM Rx- diversity GNSS1) EC21-E FDD: B1/B3/B5/B7/B8/B20 WCDMA: B1/B5/B8 900/1800 Y GPS, GLONASS, BeiDou/ Compass, Galileo, QZSS EC21-A FDD: B2/B4/B12 WCDMA: B2/B4/B5 N Y EC21-V FDD: B4/B13 N N Y EC21-AU3) FDD: B1/B2/B3/B4/B5/B7/B8/ B28 TDD: B40 WCDMA: B1/B2/B5/B8 850/900/ 1800/1900 Y EC21-AUT FDD: B1/B3/B5/B7/B28 WCDMA: B1/B5 N Y EC21-AUV FDD: B1/B3/B5/B8/B28 B1/B5/B8 N Y N EC21-J FDD: B1/B3/B8/B18/B19/B26 N N Y N EC21-KL FDD: B1/B3/B5/B7/B8 N N Y N EC20-CEL FDD: B1/B3/B5 N N N N
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 17 / 105 1. 1) GNSS function is optional. 2. 2) EC21 series module (EC21-E, EC21-A, EC21-V, EC21-AU, EC21-AUT, EC21-AUV, EC21-J, EC21-KL and EC20-CEL) contains Telematics version and Data-only version. Telematics version supports voice and data functions, while Data-only version only supports data function. 3. 3) B2 band on EC21-AU module does not support Rx-diversity. 4. Y = Supported. N = Not supported. With a compact profile of 29.0mm × 32.0mm × 2.4mm, EC21 can meet almost all requirements for M2M applications such as automotive, metering, tracking system, security, router, wireless POS, mobile computing device, PDA phone, tablet PC, etc. EC21 is an SMD type module which can be embedded into applications through its 144-pin pads, including 80 LCC signal pads and 64 other pads. 2.2. Key Features The following table describes the detailed features of EC21 module. Table 2: Key Features of EC21 Module Features Details Power Supply Supply voltage: 3.3V~4.3V Typical supply voltage: 3.8V Transmitting Power Class 4 (33dBm±2dB) for GSM850 Class 4 (33dBm±2dB) for GSM900 Class 1 (30dBm±2dB) for DCS1800 Class 1 (30dBm±2dB) for PCS1900 Class E2 (27dBm±3dB) for GSM850 8-PSK Class E2 (27dBm±3dB) for GSM900 8-PSK Class E2 (26dBm±3dB) for DCS1800 8-PSK Class E2 (26dBm±3dB) for PCS1900 8-PSK Class 3 (24dBm+1/-3dB) for WCDMA bands Class 3 (23dBm±2dB) for LTE-FDD bands Class 3 (23dBm±2dB) for LTE-TDD bands LTE Features Support up to non-CA Cat 1 FDD and TDD Support 1.4MHz~20MHz RF bandwidth Support MIMO in DL direction LTE-FDD: Max 10Mbps (DL)/5Mbps (UL) NOTES
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 18 / 105 LTE-TDD: Max 8.96Mbps (DL)/3.1Mbps (UL) UMTS Features Support 3GPP R8 DC-HSDPA, HSPA+, HSDPA, HSUPA and WCDMA Support QPSK, 16-QAM and 64-QAM modulation DC-HSDPA: Max 42Mbps (DL) HSUPA: Max 5.76Mbps (UL) WCDMA: Max 384Kbps (DL)/384Kbps (UL) GSM Features GPRS: Support GPRS multi-slot class 33 (33 by default) Coding scheme: CS-1, CS-2, CS-3 and CS-4 Max 107Kbps (DL)/85.6Kbps (UL) EDGE: Support EDGE multi-slot class 33 (33 by default) Support GMSK and 8-PSK for different MCS (Modulation and Coding Scheme) Downlink coding schemes: CS 1-4 and MCS 1-9 Uplink coding schemes: CS 1-4 and MCS 1-9 Max 296Kbps (DL)/ 236.8Kbps (UL) Internet Protocol FeaturesSupport TCP/UDP/PPP/FTP/HTTP/NTP/PING/QMI/ CMUX*/HTTPS*/ SMTP*/ MMS*/FTPS*/SMTPS*/SSL*/FILE* protocols Support PAP (Password Authentication Protocol) and CHAP (Challenge Handshake Authentication Protocol) protocols which are usually used for PPP connections SMS Text and PDU mode Point to point MO and MT SMS cell broadcast SMS storage: ME by default (U)SIM Interface Support USIM/SIM card: 1.8V, 3.0V Audio Features Support one digital audio interface: PCM interface GSM: HR/FR/EFR/AMR/AMR-WB WCDMA: AMR/AMR-WB LTE: AMR/AMR-WB Support echo cancellation and noise suppression PCM Interface Used for audio function with external codec Support 8-bit A-law*, μ-law* and 16-bit linear data formats Support long frame synchronization and short frame synchronization Support master and slave modes, but must be the master in long frame synchronization USB Interface Compliant with USB 2.0 specification (slave only); the data transfer rate can reach up to 480Mbps Used for AT command communication, data transmission, GNSS NMEA output, software debugging, firmware upgrade and voice over USB* Support USB serial drivers for: Windows XP, Windows Vista, Windows
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 19 / 105 7/8/8.1/10, Windows CE 5.0/6.0/7.0*, Linux 2.6/3.x/4.1, Android 4.x/5.x/6.x/7.x UART Interface Main UART: Used for AT command communication and data transmission Baud rates reach up to 921600bps, 115200bps by default Support RTS and CTS hardware flow control Debug UART: Used for Linux console and log output 115200bps baud rate SD Card Interface Support SD 3.0 protocol SGMII Interface Support 10/100/1000Mbps Ethernet connectivity Wireless Connectivity Interfaces Support a low-power SDIO 3.0 interface for WLAN and UART/PCM interface for Bluetooth* Rx-diversity Support LTE/WCDMA Rx-diversity GNSS Features Gen8C Lite of Qualcomm Protocol: NMEA 0183 AT Commands Compliant with 3GPP TS 27.007, 27.005 and Quectel enhanced AT commands Network Indication Two pins including NET_MODE and NET_STATUS to indicate network connectivity status Antenna Interface Including main antenna interface (ANT_MAIN), Rx-diversity antenna interface (ANT_DIV) and GNSS antenna interface (ANT_GNSS) Physical Characteristics Size: (29.0±0.15)mm × (32.0±0.15)mm × (2.4±0.2)mm Weight: approx. 4.9g Temperature Range Operation temperature range: -35°C ~ +75°C1) Extended temperature range: -40°C ~ +85°C2) Storage temperature range: -40°C ~ +90°C Firmware Upgrade USB interface and DFOTA* RoHS All hardware components are fully compliant with EU RoHS directive 1. 1) Within operating temperature range, the module is 3GPP compliant. 2. 2) Within extended temperature range, the module remains the ability to establish and maintain a voice, SMS, data transmission, emergency call, etc. There is no unrecoverable malfunction. There are also no effects on radio spectrum and no harm to radio network. Only one or more parameters like Pout might reduce in their value and exceed the specified tolerances. When the temperature returns to normal operating temperature levels, the module will meet 3GPP specifications again. 3. “*” means under development. NOTES
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 20 / 105 2.3. Functional Diagram The following figure shows a block diagram of EC21 and illustrates the major functional parts.  Power management  Baseband  DDR+NAND flash  Radio frequency  Peripheral interfaces Figure 1: Functional Diagram 2.4. Evaluation Board In order to help customers develop applications with EC21, Quectel supplies an evaluation board (EVB), USB to RS-232 converter cable, earphone, antenna and other peripherals to control or test the module.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 21 / 105 3 Application Interfaces 3.1. General Description EC21 is equipped with 80 LCC pads plus 64 LGA pads that can be connected to cellular application platform. Sub-interfaces included in these pads are described in detail in the following chapters:  Power supply  (U)SIM interface  USB interface  UART interfaces  PCM and I2C interfaces  SD card interface  ADC interfaces  Status indication  SGMII interface  Wireless connectivity interfaces  USB_BOOT interface
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 22 / 105 3.2. Pin Assignment The following figure shows the pin assignment of EC21 module. Figure 2: Pin Assignment (Top View) 1. 1) means that these pins cannot be pulled up before startup. 2. 2) PWRKEY output voltage is 0.8V because of the diode drop in the Qualcomm chipset. 3. 3) means these interface functions are only supported on Telematics version. 4. Pads 37~40, 118, 127 and 129~139 are used for wireless connectivity interfaces, among which pads 118, 127 and 129~138 are WLAN function pins, and others are Bluetooth (BT) function pins. BT function is under development. 5. Pads 119~126 and 128 are used for SGMII interface. NOTES
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 23 / 105 6. Pads 24~27 are multiplexing pins used for audio design on EC21 module and BT function on FC20 module. 7. Keep all RESERVED pins and unused pins unconnected. 8. GND pads 85~112 should be connected to ground in the design. RESERVED pads 73~84 should not be designed in schematic and PCB decal, and these pins should be served as a keep out area. 9. “*” means under development. 3.3. Pin Description The following tables show the pin definition of EC21 module. Table 3: I/O Parameters Definition Type Description IO Bidirectional DI Digital input DO Digital output PI Power input PO Power output AI Analog input AO Analog output OD Open drain Table 4: Pin Description Power Supply Pin Name Pin No. I/O Description DC Characteristics Comment VBAT_BB 59, 60 PI Power supply for module’s baseband part Vmax=4.3V Vmin=3.3V Vnorm=3.8V It must be able to provide sufficient current up to 0.8A. VBAT_RF 57, 58 PI Power supply for module’s RF part Vmax=4.3V Vmin=3.3V Vnorm=3.8V It must be able to provide sufficient current up to 1.8A in a burst
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 24 / 105 transmission. VDD_EXT 7 PO Provide 1.8V for external circuit Vnorm=1.8V IOmax=50mA Power supply for external GPIO’s pull-up circuits. If unused, keep it open. GND 8, 9, 19, 22, 36, 46, 48, 50~54, 56, 72, 85~112 Ground Turn on/off Pin Name Pin No. I/O Description DC Characteristics Comment PWRKEY 21 DI Turn on/off the module VIHmax=2.1V VIHmin=1.3V VILmax=0.5V The output voltage is 0.8V because of the diode drop in the Qualcomm chipset. RESET_N 20 DI Reset signal of the module VIHmax=2.1V VIHmin=1.3V VILmax=0.5V If unused, keep it open. Status Indication Pin Name Pin No. I/O Description DC Characteristics Comment STATUS 61 OD Indicate the module operating status The drive current should be less than 0.9mA. Require external pull-up. If unused, keep it open. NET_MODE 5 DO Indicate the module network registration mode VOHmin=1.35V VOLmax=0.45V 1.8V power domain. It cannot be pulled up before startup. If unused, keep it open. NET_ STATUS 6 DO Indicate the module network activity status VOHmin=1.35V VOLmax=0.45V 1.8V power domain. If unused, keep it open. USB Interface Pin Name Pin No. I/O Description DC Characteristics Comment USB_VBUS 71 PI USB detection Vmax=5.25V Vmin=3.0V Vnorm=5.0V Typical: 5.0V If unused, keep it open.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 25 / 105 USB_DP 69 IO USB differential data bus (+) Compliant with USB 2.0 standard specification. Require differential impedance of 90Ω. If unused, keep it open. USB_DM 70 IO USB differential data bus (-) Compliant with USB 2.0 standard specification. Require differential impedance of 90Ω. If unused, keep it open. (U)SIM Interface Pin Name Pin No. I/O Description DC Characteristics Comment USIM_GND 10 Specified ground for (U)SIM card USIM_VDD 14 PO Power supply for (U)SIM card For 1.8V (U)SIM: Vmax=1.9V Vmin=1.7V For 3.0V (U)SIM: Vmax=3.05V Vmin=2.7V IOmax=50mA Either 1.8V or 3.0V is supported by the module automatically. USIM_DATA 15 IO Data signal of (U)SIM card For 1.8V (U)SIM: VILmax=0.6V VIHmin=1.2V VOLmax=0.45V VOHmin=1.35V For 3.0V (U)SIM: VILmax=1.0V VIHmin=1.95V VOLmax=0.45V VOHmin=2.55V USIM_CLK 16 DO Clock signal of (U)SIM card For 1.8V (U)SIM: VOLmax=0.45V VOHmin=1.35V For 3.0V (U)SIM: VOLmax=0.45V VOHmin=2.55V USIM_RST 17 DO Reset signal of (U)SIM card For 1.8V (U)SIM: VOLmax=0.45V VOHmin=1.35V
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 26 / 105 For 3.0V (U)SIM: VOLmax=0.45V VOHmin=2.55V USIM_ PRESENCE 13 DI (U)SIM card insertion detection VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. If unused, keep it open. Main UART Interface Pin Name Pin No. I/O Description DC Characteristics Comment RI 62 DO Ring indicator VOLmax=0.45V VOHmin=1.35V 1.8V power domain. If unused, keep it open. DCD 63 DO Data carrier detection VOLmax=0.45V VOHmin=1.35V 1.8V power domain. If unused, keep it open. CTS 64 DO Clear to send VOLmax=0.45V VOHmin=1.35V 1.8V power domain. If unused, keep it open. RTS 65 DI Request to send VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. If unused, keep it open. DTR 66 DI Data terminal ready, sleep mode control VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. Pulled up by default. Low level wakes up the module. If unused, keep it open. TXD 67 DO Transmit data VOLmax=0.45V VOHmin=1.35V 1.8V power domain. If unused, keep it open. RXD 68 DI Receive data VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. If unused, keep it open. Debug UART Interface Pin Name Pin No. I/O Description DC Characteristics Comment DBG_TXD 12 DO Transmit data VOLmax=0.45V VOHmin=1.35V 1.8V power domain. If unused, keep it open.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 27 / 105 DBG_RXD 11 DI Receive data VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. If unused, keep it open. ADC Interface Pin Name Pin No. I/O Description DC Characteristics Comment ADC0 45 AI General purpose analog to digital converter Voltage range: 0.3V to VBAT_BB If unused, keep it open. ADC1 44 AI General purpose analog to digital converter Voltage range: 0.3V to VBAT_BB If unused, keep it open. PCM Interface Pin Name Pin No. I/O Description DC Characteristics Comment PCM_IN 24 DI PCM data input VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. If unused, keep it open. PCM_OUT 25 DO PCM data output VOLmax=0.45V VOHmin=1.35V 1.8V power domain. If unused, keep it open. PCM_SYNC 26 IO PCM data frame synchronization signal VOLmax=0.45V VOHmin=1.35V VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. In master mode, it is an output signal. In slave mode, it is an input signal. If unused, keep it open. PCM_CLK 27 IO PCM clock VOLmax=0.45V VOHmin=1.35V VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. In master mode, it is an output signal. In slave mode, it is an input signal. If unused, keep it open. I2C Interface Pin Name Pin No. I/O Description DC Characteristics Comment I2C_SCL 41 OD I2C serial clock. Used for external External pull-up resistor is required.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 28 / 105 codec 1.8V only. If unused, keep it open. I2C_SDA 42 OD I2C serial data. Used for external codec External pull-up resistor is required. 1.8V only. If unused, keep it open. SD Card Interface Pin Name Pin No. I/O Description DC Characteristics Comment SDC2_ DATA3 28 IO SD card SDIO bus DATA3 1.8V signaling: VOLmax=0.45V VOHmin=1.4V VILmin=-0.3V VILmax=0.58V VIHmin=1.27V VIHmax=2.0V 3.0V signaling: VOLmax=0.38V VOHmin=2.01V VILmin=-0.3V VILmax=0.76V VIHmin=1.72V VIHmax=3.34V SDIO signal level can be selected according to SD card supported level, more details please refer to SD 3.0 protocol. If unused, keep it open. SDC2_ DATA2 29 IO SD card SDIO bus DATA2 1.8V signaling: VOLmax=0.45V VOHmin=1.4V VILmin=-0.3V VILmax=0.58V VIHmin=1.27V VIHmax=2.0V 3.0V signaling: VOLmax=0.38V VOHmin=2.01V VILmin=-0.3V VILmax=0.76V VIHmin=1.72V VIHmax=3.34V SDIO signal level can be selected according to SD card supported level, more details please refer to SD 3.0 protocol. If unused, keep it open. SDC2_ DATA1 30 IO SD card SDIO bus DATA1 1.8V signaling: VOLmax=0.45V SDIO signal level can be selected according
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 29 / 105 VOHmin=1.4V VILmin=-0.3V VILmax=0.58V VIHmin=1.27V VIHmax=2.0V 3.0V signaling: VOLmax=0.38V VOHmin=2.01V VILmin=-0.3V VILmax=0.76V VIHmin=1.72V VIHmax=3.34V to SD card supported level, more details please refer to SD 3.0 protocol. If unused, keep it open. SDC2_ DATA0 31 IO SD card SDIO bus DATA0 1.8V signaling: VOLmax=0.45V VOHmin=1.4V VILmin=-0.3V VILmax=0.58V VIHmin=1.27V VIHmax=2.0V 3.0V signaling: VOLmax=0.38V VOHmin=2.01V VILmin=-0.3V VILmax=0.76V VIHmin=1.72V VIHmax=3.34V SDIO signal level can be selected according to SD card supported level, more details please refer to SD 3.0 protocol. If unused, keep it open. SDC2_CLK 32 DO SD card SDIO bus clock 1.8V signaling: VOLmax=0.45V VOHmin=1.4V 3.0V signaling: VOLmax=0.38V VOHmin=2.01V SDIO signal level can be selected according to SD card supported level, more details please refer to SD 3.0 protocol. If unused, keep it open. SDC2_CMD 33 IO SD card SDIO bus command 1.8V signaling: VOLmax=0.45V VOHmin=1.4V VILmin=-0.3V VILmax=0.58V VIHmin=1.27V VIHmax=2.0V SDIO signal level can be selected according to SD card supported level, more details please refer to SD 3.0 protocol. If unused, keep it open.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 30 / 105 3.0V signaling: VOLmax=0.38V VOHmin=2.01V VILmin=-0.3V VILmax=0.76V VIHmin=1.72V VIHmax=3.34V SD_INS_ DET 23 DI SD card insertion detect VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. If unused, keep it open. VDD_SDIO 34 PO SD card SDIO bus pull-up power IOmax=50mA 1.8V/2.85V configurable. Cannot be used for SD card power. If unused, keep it open. SGMII Interface Pin Name Pin No. I/O Description DC Characteristics Comment EPHY_RST_N 119 DO Ethernet PHY reset For 1.8V: VOLmax=0.45V VOHmin=1.4V For 2.85V: VOLmax=0.35V VOHmin=2.14V 1.8V/2.85V power domain. If unused, keep it open. EPHY_INT_N 120 DI Ethernet PHY interrupt VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. If unused, keep it open. SGMII_ MDATA 121 IO SGMII MDIO (Management Data Input/Output) data For 1.8V: VOLmax=0.45V VOHmin=1.4V VILmax=0.58V VIHmin=1.27V For 2.85V: VOLmax=0.35V VOHmin=2.14V VILmax=0.71V VIHmin=1.78V 1.8V/2.85V power domain. If unused, keep it open.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 31 / 105 SGMII_ MCLK 122 DO SGMII MDIO (Management Data Input/Output) clock For 1.8V: VOLmax=0.45V VOHmin=1.4V For 2.85V: VOLmax=0.35V VOHmin=2.14V 1.8V/2.85V power domain. If unused, keep it open. USIM2_VDD 128 PO SGMII MDIO pull-up power source Configurable power source. 1.8V/2.85V power domain. External pull-up for SGMII MDIO pins. If unused, keep it open. SGMII_TX_M 123 AO SGMII transmission - minus If unused, keep it open. SGMII_TX_P 124 AO SGMII transmission - plus If unused, keep it open. SGMII_RX_P 125 AI SGMII receiving - plus If unused, keep it open. SGMII_RX_M 126 AI SGMII receiving - minus If unused, keep it open. Wireless Connectivity Interfaces Pin Name Pin No. I/O Description DC Characteristics Comment SDC1_ DATA3 129 IO WLAN SDIO data bus D3 VOLmax=0.45V VOHmin=1.35V VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. If unused, keep it open. SDC1_ DATA2 130 IO WLAN SDIO data bus D2 VOLmax=0.45V VOHmin=1.35V VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. If unused, keep it open. SDC1_ DATA1 131 IO WLAN SDIO data bus D1 VOLmax=0.45V VOHmin=1.35V VILmin=-0.3V VILmax=0.6V VIHmin=1.2V 1.8V power domain. If unused, keep it open.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 32 / 105 VIHmax=2.0V SDC1_ DATA0 132 IO WLAN SDIO data bus D0 VOLmax=0.45V VOHmin=1.35V VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. If unused, keep it open. SDC1_CLK 133 DO WLAN SDIO bus clock VOLmax=0.45V VOHmin=1.35V 1.8V power domain. If unused, keep it open. SDC1_CMD 134 DO WLAN SDIO bus command VOLmax=0.45V VOHmin=1.35V 1.8V power domain. If unused, keep it open. PM_ENABLE 127 DO External power control VOLmax=0.45V VOHmin=1.35V 1.8V power domain. If unused, keep it open. WAKE_ON_ WIRELESS 135 DI Wake up the host (EC21 module) by FC20 module. VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. Active low. If unused, keep it open. WLAN_EN 136 DO WLAN function control via FC20 module VOLmax=0.45V VOHmin=1.35V 1.8V power domain. Active high. It cannot be pulled up before startup. If unused, keep it open. COEX_UART_RX 137 DI LTE/WLAN&BT coexistence signal VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. It cannot be pulled up before startup. If unused, keep it open. COEX_UART_TX 138 DO LTE/WLAN&BT coexistence signal VOLmax=0.45V VOHmin=1.35V 1.8V power domain. It cannot be pulled up before startup. If unused, keep it open. WLAN_SLP_ CLK 118 DO WLAN sleep clock If unused, keep it open. BT_RTS* 37 DI BT UART request to send VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. If unused, keep it open.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 33 / 105 BT_TXD* 38 DO BT UART transmit data VOLmax=0.45V VOHmin=1.35V 1.8V power domain. If unused, keep it open. BT_RXD* 39 DI BT UART receive data VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. If unused, keep it open. BT_CTS* 40 DO BT UART clear to send VOLmax=0.45V VOHmin=1.35V 1.8V power domain. It cannot be pulled up before startup. If unused, keep it open. BT_EN* 139 DO BT function control via FC20 module VOLmax=0.45V VOHmin=1.35V 1.8V power domain. If unused, keep it open. RF Interface Pin Name Pin No. I/O Description DC Characteristics Comment ANT_DIV 35 AI Diversity antenna pad 50Ω impedance If unused, keep it open. ANT_MAIN 49 IO Main antenna pad 50Ω impedance ANT_GNSS 47 AI GNSS antenna pad 50Ω impedance If unused, keep it open. GPIO Pins Pin Name Pin No. I/O Description DC Characteristics Comment WAKEUP_IN 1 DI Sleep mode control VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. Cannot be pulled up before startup. Low level wakes up the module. If unused, keep it open. W_DISABLE# 4 DI Airplane mode control VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. Pull-up by default. At low voltage level, module can enter into airplane mode. If unused, keep it open.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 34 / 105 1. “*” means under development. 2. Pads 24~27 are multiplexing pins used for audio design on EC21 module and BT function on FC20 module. 3.4. Operating Modes The table below briefly summarizes the various operating modes referred in the following chapters. Table 5: Overview of Operating Modes Mode Details Normal Operation Idle Software is active. The module has registered on the network, and it is ready to send and receive data. Talk/Data Network connection is ongoing. In this mode, the power consumption is decided by network setting and data transfer rate. Minimum AT+CFUN command can set the module to a minimum functionality mode without AP_READY 2 DI Application processor sleep state detection VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. If unused, keep it open. USB_BOOT Interface Pin Name Pin No. I/O Description DC Characteristics Comment USB_BOOT 115 DI Force the module to enter into emergency download mode. VILmin=-0.3V VILmax=0.6V VIHmin=1.2V VIHmax=2.0V 1.8V power domain. Active high. If unused, keep it open. RESERVED Pins Pin Name Pin No. I/O Description DC Characteristics Comment RESERVED 3, 18, 23, 43, 55, 73~84, 113, 114, 116, 117,140-144. Reserved Keep these pins unconnected. NOTES
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 35 / 105 Functionality Mode removing the power supply. In this case, both RF function and (U)SIM card will be invalid. Airplane Mode AT+CFUN command or W_DISABLE# pin can set the module to airplane mode. In this case, RF function will be invalid. Sleep Mode In this mode, the current consumption of the module will be reduced to the minimal level. During this mode, the module can still receive paging message, SMS, voice call and TCP/UDP data from the network normally. Power down Mode In this mode, the power management unit shuts down the power supply. Software is not active. The serial interface is not accessible. Operating voltage (connected to VBAT_RF and VBAT_BB) remains applied. 3.5. Power Saving 3.5.1. Sleep Mode EC21 is able to reduce its current consumption to a minimum value during the sleep mode. The following section describes power saving procedures of EC21 module. 3.5.1.1. UART Application If the host communicates with module via UART interface, the following preconditions can let the module enter into sleep mode.  Execute AT+QSCLK=1 command to enable sleep mode.  Drive DTR to high level. The following figure shows the connection between the module and the host. Figure 3: Sleep Mode Application via UART
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 36 / 105  Driving the host DTR to low level will wake up the module.  When EC21 has a URC to report, RI signal will wake up the host. Refer to Chapter 3.17 for details about RI behaviors.  AP_READY will detect the sleep state of the host (can be configured to high level or low level detection). Please refer to AT+QCFG="apready"* command for details. “*” means under development. 3.5.1.2. USB Application with USB Remote Wakeup Function If the host supports USB suspend/resume and remote wakeup functions, the following three preconditions must be met to let the module enter into sleep mode.  Execute AT+QSCLK=1 command to enable sleep mode.  Ensure the DTR is held at high level or keep it open.  The host’s USB bus, which is connected with the module’s USB interface, enters into suspended state. The following figure shows the connection between the module and the host. Figure 4: Sleep Mode Application with USB Remote Wakeup  Sending data to EC21 through USB will wake up the module.  When EC21 has a URC to report, the module will send remote wake-up signals via USB bus so as to wake up the host. NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 37 / 105 3.5.1.3. USB Application with USB Suspend/Resume and RI Function If the host supports USB suspend/resume, but does not support remote wake-up function, the RI signal is needed to wake up the host. There are three preconditions to let the module enter into the sleep mode.  Execute AT+QSCLK=1 command to enable sleep mode.  Ensure the DTR is held at high level or keep it open.  The host’s USB bus, which is connected with the module’s USB interface, enters into suspended state. The following figure shows the connection between the module and the host. Figure 5: Sleep Mode Application with RI  Sending data to EC21 through USB will wake up the module.  When EC21 has a URC to report, RI signal will wake up the host. 3.5.1.4. USB Application without USB Suspend Function If the host does not support USB suspend function, USB_VBUS should be disconnected via an additional control circuit to let the module enter into sleep mode.  Execute AT+QSCLK=1 command to enable sleep mode.  Ensure the DTR is held at high level or keep it open.  Disconnect USB_VBUS. The following figure shows the connection between the module and the host.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 38 / 105 Figure 6: Sleep Mode Application without Suspend Function Switching on the power switch to supply power to USB_VBUS will wake up the module. Please pay attention to the level match shown in dotted line between the module and the host. Refer to document [1] for more details about EC21 power management application. 3.5.2. Airplane Mode When the module enters into airplane mode, the RF function does not work, and all AT commands correlative with RF function will be inaccessible. This mode can be set via the following ways. Hardware: The W_DISABLE# pin is pulled up by default. Driving it to low level will let the module enter into airplane mode. Software: AT+CFUN command provides the choice of the functionality level through setting <fun> into 0, 1 or 4.  AT+CFUN=0: Minimum functionality mode. Both (U)SIM and RF functions are disabled.  AT+CFUN=1: Full functionality mode (by default).  AT+CFUN=4: Airplane mode. RF function is disabled. 1. W_DISABLE# control function is disabled in firmware by default. It can be enabled by AT+QCFG="airplanecontrol" command. This command is under development. 2. The execution of AT+CFUN command will not affect GNSS function. NOTES NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 39 / 105 3.6. Power Supply 3.6.1. Power Supply Pins EC21 provides four VBAT pins for connection with the external power supply. There are two separate voltage domains for VBAT.  Two VBAT_RF pins for module’s RF part.  Two VBAT_BB pins for module’s baseband part. The following table shows the details of VBAT pins and ground pins. Table 6: VBAT and GND Pins Pin Name Pin No. Description Min. Typ. Max. Unit VBAT_RF 57, 58 Power supply for module’s RF part. 3.3 3.8 4.3 V VBAT_BB 59, 60 Power supply for module’s baseband part. 3.3 3.8 4.3 V GND 8, 9, 19, 22, 36, 46, 48, 50~54, 56, 72, 85~112 Ground - 0 - V 3.6.2. Decrease Voltage Drop The power supply range of the module is from 3.3V to 4.3V. Please make sure that the input voltage will never drop below 3.3V. The following figure shows the voltage drop during burst transmission in 2G network. The voltage drop will be less in 3G and 4G networks. Figure 7: Power Supply Limits during Burst Transmission
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 40 / 105 To decrease voltage drop, a bypass capacitor of about 100µF with low ESR (ESR=0.7Ω) should be used, and a multi-layer ceramic chip (MLCC) capacitor array should also be reserved due to its ultra-low ESR. It is recommended to use three ceramic capacitors (100nF, 33pF, 10pF) for composing the MLCC array, and place these capacitors close to VBAT_BB/VBAT_RF pins. The main power supply from an external application has to be a single voltage source and can be expanded to two sub paths with star structure. The width of VBAT_BB trace should be no less than 1mm; and the width of VBAT_RF trace should be no less than 2mm. In principle, the longer the VBAT trace is, the wider it will be. In addition, in order to get a stable power source, it is suggested that a zener diode whose reverse zener voltage is 5.1V and dissipation power is more than 0.5W should be used. The following figure shows the star structure of the power supply. Figure 8: Star Structure of the Power Supply 3.6.3. Reference Design for Power Supply Power design for the module is very important, as the performance of the module largely depends on the power source. The power supply should be able to provide sufficient current up to 2A at least. If the voltage drop between the input and output is not too high, it is suggested that an LDO should be used to supply power for the module. If there is a big voltage difference between the input source and the desired output (VBAT), a buck converter is preferred to be used as the power supply. The following figure shows a reference design for +5V input power source. The typical output of the power supply is about 3.8V and the maximum load current is 3A.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 41 / 105 Figure 9: Reference Circuit of Power Supply In order to avoid damaging internal flash, please do not switch off the power supply when the module works normally. Only after the module is shut down by PWRKEY or AT command, the power supply can be cut off. 3.6.4. Monitor the Power Supply AT+CBC command can be used to monitor the VBAT_BB voltage value. For more details, please refer to document [2]. 3.7. Turn on and off Scenarios 3.7.1. Turn on Module Using the PWRKEY The following table shows the pin definition of PWRKEY. Table 7: Pin Definition of PWRKEY Pin Name Pin No. I/O Description Comment PWRKEY 21 DI Turn on/off the module The output voltage is 0.8V because of the diode drop in the Qualcomm chipset. When EC21 is in power down mode, it can be turned on to normal mode by driving the PWRKEY pin to a low level for at least 500ms. It is recommended to use an open drain/collector driver to control the PWRKEY. After STATUS pin (require external pull-up) outputting a low level, PWRKEY pin can be released. A simple reference circuit is illustrated in the following figure. NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 42 / 105 Turn on pulsePWRKEY4.7K47K≥ 500ms10nF Figure 10: Turn on the Module by Using Driving Circuit The other way to control the PWRKEY is using a button directly. When pressing the key, electrostatic strike may generate from finger. Therefore, a TVS component is indispensable to be placed nearby the button for ESD protection. A reference circuit is shown in the following figure. Figure 11: Turn on the Module by Using Button The turn on scenario is illustrated in the following figure.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 43 / 105 Figure 12: Timing of Turning on Module Please make sure that VBAT is stable before pulling down PWRKEY pin. The time between them is no less than 30ms. 3.7.2. Turn off Module The following procedures can be used to turn off the module:  Normal power down procedure: Turn off the module using the PWRKEY pin.  Normal power down procedure: Turn off the module using AT+QPOWD command. 3.7.2.1. Turn off Module Using the PWRKEY Pin Driving the PWRKEY pin to a low level voltage for at least 650ms, the module will execute power-down procedure after the PWRKEY is released. The power-down scenario is illustrated in the following figure. NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 44 / 105 Figure 13: Timing of Turning off Module 3.7.2.2. Turn off Module Using AT Command It is also a safe way to use AT+QPOWD command to turn off the module, which is similar to turning off the module via PWRKEY pin. Please refer to document [2] for details about AT+QPOWD command. 1. In order to avoid damaging internal flash, please do not switch off the power supply when the module works normally. Only after the module is shut down by PWRKEY or AT command, the power supply can be cut off. 2. When turn off module with AT command, please keep PWRKEY at high level after the execution of power-off command. Otherwise the module will be turned on again after successfully turn-off. 3.8. Reset the Module The RESET_N pin can be used to reset the module. The module can be reset by driving RESET_N to a low level voltage for time between 150ms and 460ms. NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 45 / 105 Table 8: Pin Definition of RESET_N The recommended circuit is similar to the PWRKEY control circuit. An open drain/collector driver or button can be used to control the RESET_N. Figure 14: Reference Circuit of RESET_N by Using Driving Circuit Figure 15: Reference Circuit of RESET_N by Using Button Pin Name Pin No. I/O Description Comment RESET_N 20 DI Reset the module 1.8V power domain
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 46 / 105 The reset scenario is illustrated in the following figure. Figure 16: Timing of Resetting Module 1. Use RESET_N only when turning off the module by AT+QPOWD command and PWRKEY pin failed. 2. Ensure that there is no large capacitance on PWRKEY and RESET_N pins. 3.9. (U)SIM Interface The (U)SIM interface circuitry meets ETSI and IMT-2000 requirements. Both 1.8V and 3.0V (U)SIM cards are supported. Table 9: Pin Definition of the (U)SIM Interface Pin Name Pin No. I/O Description Comment USIM_VDD 14 PO Power supply for (U)SIM card Either 1.8V or 3.0V is supported by the module automatically. USIM_DATA 15 IO Data signal of (U)SIM card USIM_CLK 16 DO Clock signal of (U)SIM card USIM_RST 17 DO Reset signal of (U)SIM card USIM_ PRESENCE 13 DI (U)SIM card insertion detection 1.8V power domain. If unused, keep it open. USIM_GND 10 Specified ground for (U)SIM card NOTES
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 47 / 105 EC21 supports (U)SIM card hot-plug via the USIM_PRESENCE pin. The function supports low level and high level detections, and is disabled by default. Please refer to document [2] about AT+QSIMDET command for details. The following figure shows a reference design for (U)SIM interface with an 8-pin (U)SIM card connector. Figure 17: Reference Circuit of (U)SIM Interface with an 8-Pin (U)SIM Card Connector If (U)SIM card detection function is not needed, please keep USIM_PRESENCE unconnected. A reference circuit for (U)SIM interface with a 6-pin (U)SIM card connector is illustrated in the following figure. Figure 18: Reference Circuit of (U)SIM Interface with a 6-Pin (U)SIM Card Connector
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 48 / 105 In order to enhance the reliability and availability of the (U)SIM card in customers’ applications, please follow the criteria below in (U)SIM circuit design:  Keep placement of (U)SIM card connector to the module as close as possible. Keep the trace length as less than 200mm as possible.  Keep (U)SIM card signals away from RF and VBAT traces.  Assure the ground between the module and the (U)SIM card connector short and wide. Keep the trace width of ground and USIM_VDD no less than 0.5mm to maintain the same electric potential. Make sure the bypass capacitor between USIM_VDD and USIM_GND less than 1uF, and place it as close to (U)SIM card connector as possible. If the ground is complete on customers’ PCB, USIM_GND can be connected to PCB ground directly.  To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and shield them with surrounded ground.  In order to offer good ESD protection, it is recommended to add a TVS diode array whose parasitic capacitance should not be more than 15pF. The 0Ω resistors should be added in series between the module and the (U)SIM card to facilitate debugging. The 33pF capacitors are used for filtering interference of GSM900MHz. Please note that the (U)SIM peripheral circuit should be close to the (U)SIM card connector.  The pull-up resistor on USIM_DATA line can improve anti-jamming capability when long layout trace and sensitive occasion are applied, and should be placed close to the (U)SIM card connector. 3.10. USB Interface EC21 contains one integrated Universal Serial Bus (USB) interface which complies with the USB 2.0 specification and supports high-speed (480Mbps) and full-speed (12Mbps) modes. The USB interface is used for AT command communication, data transmission, GNSS NMEA sentences output, software debugging, firmware upgrade and voice over USB*. The following table shows the pin definition of USB interface. Table 10: Pin Description of USB Interface Pin Name Pin No. I/O Description Comment USB_DP 69 IO USB differential data bus (+) Require differential impedance of 90Ω USB_DM 70 IO USB differential data bus (-) Require differential impedance of 90Ω USB_VBUS 71 PI Used for detecting the USB connection Typically 5.0V GND 72 Ground
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 49 / 105 For more details about the USB 2.0 specification, please visit http://www.usb.org/home. The USB interface is recommended to be reserved for firmware upgrade in customers’ designs. The following figure shows a reference circuit of USB interface. Figure 19: Reference Circuit of USB Application A common mode choke L1 is recommended to be added in series between the module and customer’s MCU in order to suppress EMI spurious transmission. Meanwhile, the 0Ω resistors (R3 and R4) should be added in series between the module and the test points so as to facilitate debugging, and the resistors are not mounted by default. In order to ensure the integrity of USB data line signal, L1/R3/R4 components must be placed close to the module, and also these resistors should be placed close to each other. The extra stubs of trace must be as short as possible. The following principles should be complied with when design the USB interface, so as to meet USB 2.0 specification.  It is important to route the USB signal traces as differential pairs with total grounding. The impedance of USB differential trace is 90Ω.  Do not route signal traces under crystals, oscillators, magnetic devices and RF signal traces. It is important to route the USB differential traces in inner-layer with ground shielding on not only upper and lower layers but also right and left sides.  Pay attention to the influence of junction capacitance of ESD protection components on USB data lines. Typically, the capacitance value should be less than 2pF.  Keep the ESD protection components to the USB connector as close as possible. 1. EC21 module can only be used as a slave device. 2. “*” means under development. NOTES
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 50 / 105 3.11. UART Interfaces The module provides two UART interfaces: the main UART interface and the debug UART interface. The following shows their features.  The main UART interface supports 4800bps, 9600bps, 19200bps, 38400bps, 57600bps, 115200bps, 230400bps, 460800bps and 921600bps baud rates, and the default is 115200bps. The interface is used for data transmission and AT command communication.  The debug UART interface supports 115200bps baud rate. It is used for Linux console and log output. The following tables show the pin definition of the UART interfaces. Table 11: Pin Definition of Main UART Interface Pin Name Pin No. I/O Description Comment RI 62 DO Ring indicator 1.8V power domain DCD 63 DO Data carrier detection CTS 64 DO Clear to send RTS 65 DI Request to send DTR 66 DI Data terminal ready TXD 67 DO Transmit data RXD 68 DI Receive data Table 12: Pin Definition of Debug UART Interface Pin Name Pin No. I/O Description Comment DBG_TXD 12 DO Transmit data 1.8V power domain DBG_RXD 11 DI Receive data 1.8V power domain
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 51 / 105 The logic levels are described in the following table. Table 13: Logic Levels of Digital I/O Parameter Min. Max. Unit VIL -0.3 0.6 V VIH 1.2 2.0 V VOL 0 0.45 V VOH 1.35 1.8 V The module provides 1.8V UART interface. A level translator should be used if customers’ application is equipped with a 3.3V UART interface. A level translator TXS0108EPWR provided by Texas Instruments is recommended. The following figure shows a reference design. Figure 20: Reference Circuit with Translator Chip Please visit http://www.ti.com for more information. Another example with transistor translation circuit is shown as below. The circuit design of dotted line section can refer to the design of solid line section, in terms of both module input and output circuit designs, but please pay attention to the direction of connection.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 52 / 105 Figure 21: Reference Circuit with Transistor Circuit Transistor circuit solution is not suitable for applications with high baud rates exceeding 460Kbps. 3.12. PCM and I2C Interfaces EC21 provides one Pulse Code Modulation (PCM) digital interface for audio design, which supports the following modes and one I2C interface:  Primary mode (short frame synchronization, works as both master and slave)  Auxiliary mode (long frame synchronization, works as master only) In primary mode, the data is sampled on the falling edge of the PCM_CLK and transmitted on the rising edge. The PCM_SYNC falling edge represents the MSB. In this mode, the PCM interface supports 256kHz, 512kHz, 1024kHz or 2048kHz PCM_CLK at 8kHz PCM_SYNC, and also supports 4096kHz PCM_CLK at 16kHz PCM_SYNC. In auxiliary mode, the data is sampled on the falling edge of the PCM_CLK and transmitted on the rising edge. The PCM_SYNC rising edge represents the MSB. In this mode, the PCM interface operates with a 256kHz, 512kHz, 1024kHz or 2048kHz PCM_CLK and an 8kHz, 50% duty cycle PCM_SYNC. EC21 supports 8-bit A-law* and μ-law*, and also 16-bit linear data formats. The following figures show the primary mode’s timing relationship with 8kHz PCM_SYNC and 2048kHz PCM_CLK, as well as the auxiliary mode’s timing relationship with 8kHz PCM_SYNC and 256kHz PCM_CLK. NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 53 / 105 Figure 22: Primary Mode Timing Figure 23: Auxiliary Mode Timing The following table shows the pin definition of PCM and I2C interfaces which can be applied on audio codec design. Table 14: Pin Definition of PCM and I2C Interfaces Pin Name Pin No. I/O Description Comment PCM_IN 24 DI PCM data input 1.8V power domain PCM_OUT 25 DO PCM data output 1.8V power domain
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 54 / 105 PCM_SYNC 26 IO PCM data frame synchronization signal 1.8V power domain PCM_CLK 27 IO PCM data bit clock 1.8V power domain I2C_SCL 41 OD I2C serial clock Require external pull-up to 1.8V I2C_SDA 42 OD I2C serial data Require external pull-up to 1.8V Clock and mode can be configured by AT command, and the default configuration is master mode using short frame synchronization format with 2048KHz PCM_CLK and 8KHz PCM_SYNC. Please refer to document [2] about AT+QDAI command for details. The following figure shows a reference design of PCM interface with external codec IC. Figure 24: Reference Circuit of PCM Application with Audio Codec 1. “*” means under development. 2. It is recommended to reserve RC (R=22Ω, C=22pF) circuits on the PCM lines, especially for PCM_CLK. 3. EC21 works as a master device pertaining to I2C interface. 3.13. SD Card Interface EC21 supports SDIO3.0 interface for SD card. The following table shows the pin definition of SD card interface. NOTES
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 55 / 105 Table 15: Pin Definition of SD Card Interface Pin Name Pin No. I/O Description Comment SDC2_DATA3 28 IO SD card SDIO bus DATA3 SDIO signal level can be selected according to SD card supported level, more details please refer to SD 3.0 protocol. If unused, keep it open. SDC2_DATA2 29 IO SD card SDIO bus DATA2 SDIO signal level can be selected according to SD card supported level, more details please refer to SD 3.0 protocol. If unused, keep it open. SDC2_DATA1 30 IO SD card SDIO bus DATA1 SDIO signal level can be selected according to SD card supported level, more details please refer to SD 3.0 protocol. If unused, keep it open. SDC2_DATA0 31 IO SD card SDIO bus DATA0 SDIO signal level can be selected according to SD card supported level, more details please refer to SD 3.0 protocol. If unused, keep it open. SDC2_CLK 32 DO SD card SDIO bus clock SDIO signal level can be selected according to SD card supported level, more details please refer to SD 3.0 protocol. If unused, keep it open. SDC2_CMD 33 IO SD card SDIO bus command SDIO signal level can be selected according to SD card supported level, more details please refer to SD 3.0 protocol. If unused, keep it open. VDD_SDIO 34 PO SD card SDIO bus pull up power 1.8V/2.85V configurable. Cannot be used for SD card power. If unused, keep it open.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 56 / 105 SD_INS_DET 23 DI SD card insertion detection 1.8V power domain. If unused, keep it open. The following figure shows a reference design of SD card. Figure 25: Reference Circuit of SD card In SD card interface design, in order to ensure good communication performance with SD card, the following design principles should be complied with:  The voltage range of SD card power supply VDD_3V is 2.7V~3.6V and a sufficient current up to 0.8A should be provided. As the maximum output current of VDD_SDIO is 50mA which can only be used for SDIO pull-up resistors, an externally power supply is needed for SD card.  To avoid jitter of bus, resistors R7~R11 are needed to pull up the SDIO to VDD_SDIO. Value of these resistors is among 10KΩ~100KΩ and the recommended value is 100KΩ. VDD_SDIO should be used as the pull-up power.  In order to adjust signal quality, it is recommended to add 0Ω resistors R1~R6 in series between the module and the SD card. The bypass capacitors C1~C6 are reserved and not mounted by default. All resistors and bypass capacitors should be placed close to the module.  In order to offer good ESD protection, it is recommended to add a TVS diode on SD card pins near the SD card connector with junction capacitance less than 15pF.  Keep SDIO signals far away from other sensitive circuits/signals such as RF circuits, analog signals, etc., as well as noisy signals such as clock signals, DCDC signals, etc.  It is important to route the SDIO signal traces with total grounding. The impedance of SDIO data trace is 50Ω (±10%).  Make sure the adjacent trace spacing is two times of the trace width and the load capacitance of SDIO bus should be less than 15pF.  It is recommended to keep the trace length difference between CLK and DATA/CMD less than 1mm and the total routing length less than 50mm. The total trace length inside the module is 27mm, so the exterior total trace length should be less than 23mm.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 57 / 105 3.14. ADC Interfaces The module provides two analog-to-digital converter (ADC) interfaces. AT+QADC=0 command can be used to read the voltage value on ADC0 pin. AT+QADC=1 command can be used to read the voltage value on ADC1 pin. For more details about these AT commands, please refer to document [2]. In order to improve the accuracy of ADC, the trace of ADC should be surrounded by ground. Table 16: Pin Definition of ADC Interfaces Pin Name Pin No. Description ADC0 45 General purpose analog to digital converter ADC1 44 General purpose analog to digital converter The following table describes the characteristic of ADC function. Table 17: Characteristic of ADC Parameter Min. Typ. Max. Unit ADC0 Voltage Range 0.3 VBAT_BB V ADC1 Voltage Range 0.3 VBAT_BB V ADC Resolution 15 bits 1. ADC input voltage must not exceed VBAT_BB. 2. It is prohibited to supply any voltage to ADC pins when VBAT is removed. 3. It is recommended to use a resistor divider circuit for ADC application. 3.15. Network Status Indication The network indication pins can be used to drive network status indication LEDs. The module provides two pins which are NET_MODE and NET_STATUS. The following tables describe the pin definition and logic level changes in different network status. NOTES
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 58 / 105 Table 18: Pin Definition of Network Connection Status/Activity Indicator Pin Name Pin No. I/O Description Comment NET_MODE1) 5 DO Indicate the module’s network registration status 1.8V power domain Cannot be pulled up before startup NET_STATUS 6 DO Indicate the module’s network activity status 1.8V power domain Table 19: Working State of Network Connection Status/Activity Indicator Pin Name Logic Level Changes Network Status NET_MODE Always High Registered on LTE network Always Low Others NET_STATUS Flicker slowly (200ms High/1800ms Low) Network searching Flicker slowly (1800ms High/200ms Low) Idle Flicker quickly (125ms High/125ms Low) Data transfer is ongoing Always High Voice calling A reference circuit is shown in the following figure. Figure 26: Reference Circuit of the Network Indicator
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 59 / 105 3.16. STATUS The STATUS pin is an open drain output for indicating the module’s operation status. Customers can connect it to a GPIO of DTE with a pull up resistor, or as the LED indication circuit shown below. When the module is turned on normally, the STATUS will present the low state. Otherwise, the STATUS will present high-impedance state. Table 20: Pin Definition of STATUS Pin Name Pin No. I/O Description Comment STATUS 61 OD Indicate the module’s operation status An external pull-up resistor is required. If unused, keep it open. The following figure shows different circuit designs of STATUS, and customers can choose either one according to their application demands. Figure 27: Reference Circuits of STATUS 3.17. Behaviors of RI AT+QCFG="risignaltype","physical" command can be used to configure RI behavior. No matter on which port URC is presented, URC will trigger the behavior of RI pin.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 60 / 105 URC can be outputted from UART port, USB AT port and USB modem port through configuration via AT+QURCCFG command. The default port is USB AT port. In addition, RI behavior can be configured flexibly. The default behavior of the RI is shown as below. Table 21: Behavior of RI State Response Idle RI keeps at high level URC RI outputs 120ms low pulse when a new URC returns The RI behavior can be changed by AT+QCFG="urc/ri/ring" command. Please refer to document [2] for details. 3.18. SGMII Interface EC21 includes an integrated Ethernet MAC with an SGMII interface and two management interfaces, key features of the SGMII interface are shown below:  IEEE802.3 compliance  Support 10M/100M/1000M Ethernet work mode  Support VLAN tagging  Support IEEE1588 and Precision Time Protocol (PTP)  Can be used to connect to external Ethernet PHY like AR8033, or to an external switch  Management interfaces support dual voltage 1.8V/2.85V The following table shows the pin definition of SGMII interface. Table 22: Pin Definition of the SGMII Interface Pin Name Pin No. I/O Description Comment Control Signal Part EPHY_RST_N 119 DO Ethernet PHY reset 1.8V/2.85V power domain EPHY_INT_N 120 DI Ethernet PHY interrupt 1.8V power domain NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 61 / 105 SGMII_MDATA 121 IO SGMII MDIO (Management Data Input/Output) data 1.8V/2.85V power domain SGMII_MCLK 122 DO SGMII MDIO (Management Data Input/Output) clock 1.8V/2.85V power domain USIM2_VDD 128 PO SGMII MDIO pull-up power source Configurable power source. 1.8V/2.85V power domain. External pull-up power source for SGMII MDIO pins. SGMII Signal Part SGMII_TX_M 123 AO SGMII transmission-minus Connect with a 0.1uF capacitor, close to the PHY side. SGMII_TX_P 124 AO SGMII transmission-plus Connect with a 0.1uF capacitor, close to the PHY side. SGMII_RX_P 125 AI SGMII receiving-plus Connect with a 0.1uF capacitor, close to EC21 module. SGMII_RX_M 126 AI SGMII receiving-minus Connect with a 0.1uF capacitor, close to EC21 module. The following figure shows the simplified block diagram for Ethernet application. Module AR8033 EthernetTransformer RJ45SGMIIControlMDI Figure 28: Simplified Block Diagram for Ethernet Application
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 62 / 105 The following figure shows a reference design of SGMII interface with PHY AR8033 application. Figure 29: Reference Circuit of SGMII Interface with PHY AR8033 Application In order to enhance the reliability and availability in customers’ applications, please follow the criteria below in the Ethernet PHY circuit design:  Keep SGMII data and control signals away from other sensitive circuits/signals such as RF circuits, analog signals, etc., as well as noisy signals such as clock signals, DCDC signals, etc.  Keep the maximum trace length less than 10-inch and keep skew on the differential pairs less than 20mil.  The differential impedance of SGMII data trace is 100Ω±10%, and the reference ground of the area should be complete.  Make sure the trace spacing between SGMII RX and TX is at least 3 times of the trace width, and the same to the adjacent signal traces. 3.19. Wireless Connectivity Interfaces EC21 supports a low-power SDIO 3.0 interface for WLAN and a UART/PCM interface for BT. The following table shows the pin definition of wireless connectivity interfaces.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 63 / 105 Table 23: Pin Definition of Wireless Connectivity Interfaces Pin Name Pin No. I/O Description Comment WLAN Part SDC1_DATA3 129 IO SDIO data bus D3 1.8V power domain SDC1_DATA2 130 IO SDIO data bus D2 1.8V power domain SDC1_DATA1 131 IO SDIO data bus D1 1.8V power domain SDC1_DATA0 132 IO SDIO data bus D0 1.8V power domain SDC1_CLK 133 DO SDIO clock 1.8V power domain SDC1_CMD 134 IO SDIO command 1.8V power domain WLAN_EN 136 DO WLAN function control via FC20 module. 1.8V power domain Active high. It cannot be pulled up before startup Coexistence and Control Part PM_ENABLE 127 DO External power control 1.8V power domain WAKE_ON_ WIRELESS 135 DI Wake up the host (EC21 module) by FC20 module 1.8V power domain COEX_UART_RX 137 DI LTE/WLAN&BT coexistence signal 1.8V power domain It cannot be pulled up before startup COEX_UART_TX 138 DO LTE/WLAN&BT coexistence signal 1.8V power domain It cannot be pulled up before startup WLAN_SLP_CLK 118 DO WLAN sleep clock BT Part* BT_RTS* 37 DI BT UART request to send 1.8V power domain BT_TXD* 38 DO BT UART transmit data 1.8V power domain BT_RXD* 39 DI BT UART receive data 1.8V power domain BT_CTS* 40 DO BT UART clear to send 1.8V power domain It cannot be pulled up before startup
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 64 / 105 PCM_IN1) 24 DI PCM data input 1.8V power domain PCM_OUT1) 25 DO PCM data output 1.8V power domain PCM_SYNC1) 26 IO PCM data frame synchronization signal 1.8V power domain PCM_CLK1) 27 IO PCM data bit clock 1.8V power domain BT_EN* 139 DO WLAN function control via FC20 module. 1.8V power domain Active high. The following figure shows a reference design of wireless connectivity interfaces with Quectel FC20 module. ModuleWAKE_ON_WIREL ESSWLAN_SLP_CLKPM_ENABL EDCDC/LDO32KHZ_INWAKE_ON_WIREL ESSFC20 ModuleVDD_3V3POWERSDC1_DATA3SDC1_DATA2SDC1_DATA1SDC1_DATA0SDC1_CLKSDC1_CMDWLAN_ENSDIO_D3SDIO_D2SDIO_D1SDIO_D0SDIO_CLKSDIO_CMDWLAN_ENWLANBT_ENBT_RTSBT_CTSBT_TXDBT_RXDPCM_INPCM_OUTPCM_SYNCPCM_CLKBT_ENBT_UART_RTSBT_UART_CTSBT_UART_RXDBT_UART_TXDPCM_OUTPCM_INPCM_SYNCPCM_CLKVDD_EXT VIOCOEX_UART_TXCOEX_UART_RX LTE_UART_TXDLTE_UART_RXDCOEXBluetooth* Figure 30: Reference Circuit of Wireless Connectivity Interfaces with FC20 Module 1. FC20 module can only be used as a slave device. 2. When BT function is enabled on EC21 module, PCM_SYNC and PCM_CLK pins are only used to NOTES
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 65 / 105 output signals. 3. For more information about wireless connectivity interfaces, please refer to document [5]. 4. “*” means under development. 5. 1) Pads 24~27 are multiplexing pins used for audio design on EC25 module and BT function on FC20 module. 3.19.1. WLAN Interface EC21 provides a low power SDIO 3.0 interface and control interface for WLAN design. SDIO interface supports the SDR mode (up to 50MHz). As SDIO signals are very high-speed, in order to ensure the SDIO interface design corresponds with the SDIO 3.0 specification, please comply with the following principles:  It is important to route the SDIO signal traces with total grounding. The impedance of SDIO signal trace is 50Ω (±10%).  Protect other sensitive signals/circuits (RF, analog signals, etc.) from SDIO corruption and protect SDIO signals from noisy signals (clocks, DCDCs, etc.).  It is recommended to keep matching length between CLK and DATA/CMD less than 1mm and total routing length less than 50mm.  Keep termination resistors within 15Ω~24Ω on clock lines near the module and keep the route distance from the module clock pins to termination resistors less than 5mm.  Make sure the adjacent trace spacing is is 2 times of the trace width and bus capacitance is less than 15pF. 3.19.2. BT Interface* EC21 supports a dedicated UART interface and a PCM interface for BT function application. Further information about BT interface will be added in future version of this document. “*” means under development. NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 66 / 105 3.20. USB_BOOT Interface EC21 provides a USB_BOOT pin. Developers can pull up USB_BOOT to VDD_EXT before powering on the module, thus the module will enter into emergency download mode when powered on. In this mode, the module supports firmware upgrade over USB interface. Table 24: Pin Definition of USB_BOOT Interface Pin Name Pin No. I/O Description Comment USB_BOOT 115 DI Force the module enter into emergency download mode 1.8V power domain. Active high. It is recommended to reserve test point. The following figure shows a reference circuit of USB_BOOT interface. ModuleUSB_BOOTVDD_EXT4.7KTest pointTVSCl ose to test po in t Figure 31: Reference Circuit of USB_BOOT Interface
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 67 / 105 4 GNSS Receiver 4.1. General Description EC21 includes a fully integrated global navigation satellite system solution that supports Gen8C-Lite of Qualcomm (GPS, GLONASS, BeiDou, Galileo and QZSS). EC21 supports standard NMEA-0183 protocol, and outputs NMEA sentences at 1Hz data update rate via USB interface by default. By default, EC21 GNSS engine is switched off. It has to be switched on via AT command. For more details about GNSS engine technology and configurations, please refer to document [3]. 4.2. GNSS Performance The following table shows the GNSS performance of EC21. Table 25: GNSS Performance Parameter Description Conditions Typ. Unit Sensitivity (GNSS) Cold start Autonomous -146 dBm Reacquisition Autonomous -157 dBm Tracking Autonomous -157 dBm TTFF (GNSS) Cold start @open sky Autonomous 35 s XTRA enabled 18 s Warm start @open sky Autonomous 26 s XTRA enabled 2.2 s
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 68 / 105 Hot start @open sky Autonomous 2.5 s XTRA enabled 1.8 s Accuracy (GNSS) CEP-50 Autonomous @open sky <1.5 m 1. Tracking sensitivity: the lowest GNSS signal value at the antenna port on which the module can keep on positioning for 3 minutes. 2. Reacquisition sensitivity: the lowest GNSS signal value at the antenna port on which the module can fix position again within 3 minutes after loss of lock. 3. Cold start sensitivity: the lowest GNSS signal value at the antenna port on which the module fixes position within 3 minutes after executing cold start command. 4.3. Layout Guidelines The following layout guidelines should be taken into account in customers’ designs.  Maximize the distance among GNSS antenna, main antenna and the Rx-diversity antenna.  Digital circuits such as (U)SIM card, USB interface, camera module and display connector should be kept away from the antennas.  Use ground vias around the GNSS trace and sensitive analog signal traces to provide coplanar isolation and protection.  Keep 50Ω characteristic impedance for the ANT_GNSS trace. Please refer to Chapter 5 for GNSS antenna reference design and antenna installation consideration. NOTES
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 69 / 105 5 Antenna Interfaces EC21 antenna interfaces include a main antenna interface, an Rx-diversity antenna interface which is used to resist the fall of signals caused by high speed movement and multipath effect, and a GNSS antenna interface. The impedance of the antenna port is 50Ω. 5.1. Main/Rx-diversity Antenna Interfaces 5.1.1. Pin Definition The pin definition of main antenna and Rx-diversity antenna interfaces is shown below. Table 26: Pin Definition of RF Antennas Pin Name Pin No. I/O Description Comment ANT_MAIN 49 IO Main antenna pad 50Ω impedance ANT_DIV 35 AI Receive diversity antenna pad 50Ω impedance 5.1.2. Operating Frequency Table 27: Module Operating Frequencies 3GPP Band Transmit Receive Unit GSM850 824~849 869~894 MHz EGSM900 880~915 925~960 MHz DCS1800 1710~1785 1805~1880 MHz PCS1900 1850~1910 1930~1990 MHz WCDMA B1 1920~1980 2110~2170 MHz WCDMA B2 1850~1910 1930~1990 MHz
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 70 / 105 WCDMA B4 1710~1755 2110~2155 MHz WCDMA B5 824~849 869~894 MHz WCDMA B8 880~915 925~960 MHz LTE FDD B1 1920~1980 2110~2170 MHz LTE FDD B2 1850~1910 1930~1990 MHz LTE FDD B3 1710~1785 1805~1880 MHz LTE FDD B4 1710~1755 2110~2155 MHz LTE FDD B5 824~849 869~894 MHz LTE FDD B7 2500~2570 2620~2690 MHz LTE FDD B8 880~915 925~960 MHz LTE FDD B12 699~716 729~746 MHz LTE FDD B13 777~787 746~756 MHz LTE FDD B18 815~830 860~875 MHz LTE FDD B19 830~845 875~890 MHz LTE FDD B20 832~862 791~821 MHz LTE FDD B26 814~849 859~894 MHz LTE FDD B28 703~748 758~803 MHz LTE TDD B40 2300~2400 2300~2400 MHz 5.1.3. Reference Design of RF Antenna Interface A reference design of ANT_MAIN and ANT_DIV antenna pads is shown as below. A π-type matching circuit should be reserved for better RF performance. The capacitors are not mounted by default.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 71 / 105 Figure 32: Reference Circuit of RF Antenna Interface 1. Keep a proper distance between the main antenna and the Rx-diversity antenna to improve the receiving sensitivity. 2. ANT_DIV function is enabled by default. 3. Place the π-type matching components (R1, C1, C2, R2, C3, C4) as close to the antenna as possible. 5.1.4. Reference Design of RF Layout For user’s PCB, the characteristic impedance of all RF traces should be controlled as 50Ω. The impedance of the RF traces is usually determined by the trace width (W), the materials’ dielectric constant, the distance between signal layer and reference ground (H), and the clearance between RF trace and ground (S). Microstrip line or coplanar waveguide line is typically used in RF layout for characteristic impedance control. The following are reference designs of microstrip line or coplanar waveguide line with different PCB structures . Figure 33: Microstrip Line Design on a 2-layer PCB NOTES
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 72 / 105 Figure 34: Coplanar Waveguide Line Design on a 2-layer PCB Figure 35: Coplanar Waveguide Line Design on a 4-layer PCB (Layer 3 as Reference Ground) Figure 36: Coplanar Waveguide Line Design on a 4-layer PCB (Layer 4 as Reference Ground) In order to ensure RF performance and reliability, the following principles should be complied with in RF layout design:
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 73 / 105  Use impedance simulation tool to control the characteristic impedance of RF traces as 50Ω.  The GND pins adjacent to RF pins should not be designed as thermal relief pads, and should be fully connected to ground.  The distance between the RF pins and the RF connector should be as short as possible, and all the right angle traces should be changed to curved ones.  There should be clearance area under the signal pin of the antenna connector or solder joint.  The reference ground of RF traces should be complete. Meanwhile, adding some ground vias around RF traces and the reference ground could help to improve RF performance. The distance between the ground vias and RF traces should be no less than two times the width of RF signal traces (2*W). For more details about RF layout, please refer to document [6]. 5.2. GNSS Antenna Interface The following tables show the pin definition and frequency specification of GNSS antenna interface. Table 28: Pin Definition of GNSS Antenna Interface Pin Name Pin No. I/O Description Comment ANT_GNSS 47 AI GNSS antenna 50Ω impedance Table 29: GNSS Frequency Type Frequency Unit GPS/Galileo/QZSS 1575.42±1.023 MHz GLONASS 1597.5~1605.8 MHz BeiDou 1561.098±2.046 MHz
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 74 / 105 A reference design of GNSS antenna is shown as below. Figure 37: Reference Circuit of GNSS Antenna 1. An external LDO can be selected to supply power according to the active antenna requirement. 2. If the module is designed with a passive antenna, then the VDD circuit is not needed. 5.3. Antenna Installation 5.3.1. Antenna Requirement The following table shows the requirements on main antenna, Rx-diversity antenna and GNSS antenna. Table 30: Antenna Requirements Type Requirements GNSS1) Frequency range: 1561MHz~1615MHz Polarization: RHCP or linear VSWR: <2 (Typ.) Passive antenna gain: > 0dBi Active antenna noise figure: <1.5dB Active antenna gain: > 0dBi Active antenna embedded LNA gain: <17 dB GSM/WCDMA/LTE VSWR: ≤2 Efficiency: > 30% NOTES
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 75 / 105 Max Input Power: 50 W Input Impedance: 50Ω Cable insertion loss: <1dB (GSM850, GSM900, WCDMA B5/B8, LTE-FDD B5/B8/B12/B13/B18/B19/B20/B26/B28) Cable insertion loss: <1.5dB (DCS1800, PCS1900, WCDMA B1/B2/B4, LTE B1/B2/B3/B4) Cable insertion loss <2dB (LTE-FDD B7, LTE-TDD B40) 1) It is recommended to use a passive antenna when the module supports B13 or B14, because harmonics will be generated when using an active antenna, which will affect the GNSS performance 5.3.2. Recommended RF Connector for Antenna Installation If RF connector is used for antenna connection, it is recommended to use U.FL-R-SMT connector provided by Hirose. Figure 38: Dimensions of the U.FL-R-SMT Connector (Unit: mm) NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 76 / 105 U.FL-LP serial connectors listed in the following figure can be used to match the U.FL-R-SMT. Figure 39: Mechanicals of U.FL-LP Connectors The following figure describes the space factor of mated connector. Figure 40: Space Factor of Mated Connector (Unit: mm) For more details, please visit http://www.hirose.com.
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 77 / 105 6 Electrical, Reliability and Radio Characteristics 6.1. Absolute Maximum Ratings Absolute maximum ratings for power supply and voltage on digital and analog pins of the module are listed in the following table. Table 31: Absolute Maximum Ratings Parameter Min. Max. Unit VBAT_RF/VBAT_BB -0.3 4.7 V USB_VBUS -0.3 5.5 V Peak Current of VBAT_BB 0 0.8 A Peak Current of VBAT_RF 0 1.8 A Voltage at Digital Pins -0.3 2.3 V Voltage at ADC0 0 VBAT_BB V Voltage at ADC1 0 VBAT_BB V
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 78 / 105 6.2. Power Supply Ratings Table 32: Power Supply Ratings Parameter Description Conditions Min. Typ. Max. Unit VBAT VBAT_BB and VBAT_RF The actual input voltages must stay between the minimum and maximum values. 3.3 3.8 4.3 V Voltage drop during burst transmission Maximum power control level on GSM900 400 mV IVBAT Peak supply current (during transmission slot) Maximum power control level on GSM900 1.8 2.0 A USB_VBUS USB detection 3.0 5.0 5.25 V 6.3. Operation and Storage Temperatures The operation and storage temperatures are listed in the following table. Table 33: Operation and Storage Temperatures Parameter Min. Typ. Max. Unit Operation Temperature Range1) -35 +25 +75 ºC Extended Temperature Range2) -40 +85 ºC Storage Temperature Range -40 +90 ºC 1. 1) Within operation temperature range, the module is 3GPP compliant. 2. 2) Within extended temperature range, the module remains the ability to establish and maintain a voice, SMS, data transmission, emergency call, etc. There is no unrecoverable malfunction. There are also no effects on radio spectrum and no harm to radio network. Only one or more parameters like Pout might reduce in their value and exceed the specified tolerances. When the temperature returns to the normal operating temperature levels, the module will meet 3GPP specifications again. NOTES
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 79 / 105 6.4. Current Consumption The values of current consumption are shown below. Table 34: EC21-E Current Consumption Parameter Description Conditions Typ. Unit IVBAT OFF state Power down 13 uA Sleep state AT+CFUN=0 (USB disconnected) 1.4 mA GSM900 @DRX=9 (USB disconnected) 1.8 mA DCS1800 @DRX=9 (USB disconnected) 1.8 mA WCDMA PF=64 (USB disconnected) 2.4 mA WCDMA PF=128 (USB disconnected) 1.9 mA FDD-LTE PF=64 (USB disconnected) 3.2 mA FDD-LTE PF=128 (USB disconnected) 2.1 mA Idle state (GNSS OFF) GSM900 @DRX=5 (USB disconnected) 22.0 mA GSM900 @DRX=5 (USB connected) 32.0 mA WCDMA PF=64 (USB disconnected) 22.5 mA WCDMA PF=64 (USB connected) 32.7 mA LTE-FDD PF=64 (USB disconnected) 22.5 mA LTE-FDD PF=64 (USB connected) 32.5 mA GPRS data transfer (GNSS OFF) GSM900 4DL/1UL @32.3dBm 220 mA GSM900 3DL/2UL @32.18dBm 387 mA GSM900 2DL/3UL @30.3dBm 467 mA GSM900 1DL/4UL @29.4dBm 555 mA DCS1800 4DL/1UL @29.6dBm 185 mA DCS1800 3DL/2UL @29.1dBm 305 mA
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 80 / 105 DCS1800 2DL/3UL @28.8dBm 431 mA DCS1800 1DL/4UL @29.1dBm 540 mA EDGE data transfer (GNSS OFF) GSM900 4DL/1UL @26dBm 148 mA GSM900 3DL/2UL @26dBm 245 mA GSM900 2DL/3UL @25dBm 338 mA GSM900 1DL/4UL @25dBm 432 mA DCS1800 4DL/1UL @26dBm 150 mA DCS1800 3DL/2UL @25dBm 243 mA DCS1800 2DL/3UL @25dBm 337 mA DCS1800 1DL/4UL @25dBm 430 mA WCDMA data transfer (GNSS OFF) WCDMA B1 HSDPA @22.5dBm 659 mA WCDMA B1 HSUPA @21.11dBm 545 mA WCDMA B5 HSDPA @23.5dBm 767 mA WCDMA B5 HSUPA @21.4dBm 537 mA WCDMA B8 HSDPA @22.41dBm 543 mA WCDMA B8 HSUPA @21.2dBm 445 mA LTE data transfer (GNSS OFF) LTE-FDD B1 @23.45dBm 807 mA LTE-FDD B3 @23.4dBm 825 mA LTE-FDD B5 @23.4dBm 786 mA LTE-FDD B7 @23.86dBm 887 mA LTE-FDD B8 @23.5dBm 675 mA LTE-FDD B20 @23.57dBm 770 mA GSM voice call GSM900 PCL=5 @32.8dBm 336 mA PCS1800 PCL=0 @29.3dBm 291 mA WCDMA voice call WCDMA B1 @23.69dBm 683 mA
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 81 / 105 WCDMA B5 @23.61dBm 741 mA WCDMA B8 @23.35dBm 564 mA Table 35: EC21-A Current Consumption Parameter Description Conditions Typ. Unit IVBAT OFF state Power down 10 uA Sleep state AT+CFUN=0 (USB disconnected) 1.25 mA WCDMA PF=64 (USB disconnected) 2.03 mA WCDMA PF=128 (USB disconnected) 1.65 mA LTE-FDD PF=64 (USB disconnected) 2.31 mA LTE-FDD PF=128 (USB disconnected) 1.85 mA Idle state (GNSS OFF) WCDMA PF=64 (USB disconnected) 23.1 mA WCDMA PF=64 (USB connected) 32.8 mA LTE-FDD PF=64 (USB disconnected) 22.8 mA LTE-FDD PF=64 (USB connected) 32.8 mA WCDMA data transfer (GNSS OFF) WCDMA B2 HSDPA @21.54dBm 479.0 mA WCDMA B2 HSUPA @22.19dBm 530.0 mA WCDMA B4 HSDPA @22.15dBm 539.0 mA WCDMA B4 HSUPA @21.82dBm 531.0 mA WCDMA B5 HSDPA @22.22dBm 454.0 mA WCDMA B5 HSUPA @21.45dBm 433.0 mA LTE data transfer (GNSS OFF) LTE-FDD B2 @23.11dBm 721.0 mA LTE-FDD B4 @23.16dBm 748.0 mA LTE-FDD B12 @23.25dBm 668.0 mA WCDMA voice call WCDMA B2 @22.97dBm 565.0 mA
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 82 / 105 Table 36: EC21-V Current Consumption Table 37: EC21-AUT Current Consumption WCDMA B4 @22.91dBm 590.0 mA WCDMA B5 @23.06dBm 493.0 mA Parameter Description Conditions Typ. Unit IVBAT OFF state Power down 10 uA Sleep state AT+CFUN=0 (USB disconnected) 1.07 mA LTE-FDD PF=64 (USB disconnected) 2.85 mA LTE-FDD PF=128 (USB disconnected) 2.26 mA Idle state (GNSS OFF) LTE-FDD PF=64 (USB disconnected) 22.0 mA LTE-FDD PF=64 (USB connected) 32.0 mA LTE data transfer (GNSS OFF) LTE-FDD B4 @22.77dBm 762.0 mA LTE-FDD B13 @23.05dBm 533.0 mA Parameter Description Conditions Typ. Unit IVBAT OFF state Power down 10 uA Sleep state AT+CFUN=0 (USB disconnected) 0.99 mA WCDMA PF=64 (USB disconnected) 2.1 mA WCDMA PF=128 (USB disconnected) 1.7 mA LTE-FDD PF=64 (USB disconnected) 2.9 mA LTE-FDD PF=128 (USB disconnected) 2.4 mA Idle state WCDMA PF=64 (USB disconnected) 22.0 mA WCDMA PF=64 (USB connected) 32.0 mA LTE-FDD PF=64 (USB disconnected) 23.6 mA LTE-FDD PF=64 (USB connected) 33.6 mA
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 83 / 105 Table 38: EC21-AUV Current Consumption WCDMA data (GNSS OFF) WCDMA B1 HSDPA @22.59dBm 589.0 mA WCDMA B1 HSUPA @22.29dBm 623.0 mA WCDMA B5 HSDPA @22.22dBm 511.0 mA WCDMA B5 HSUPA @21.64dBm 503.0 mA LTE data transfer (GNSS OFF) LTE-FDD B1 @23.38dBm 813.0 mA LTE-FDD B3 @22.87dBm 840.0 mA LTE-FDD B5 @23.12dBm 613.0 mA LTE-FDD B7 @22.96dBm 761.0 mA LTE-FDD B28 @23.31dBm 650.0 mA WCDMA voice call WCDMA B1 @24.21dBm 687.0 mA WCDMA B5 @23.18dBm 535.0 mA Parameter Description Conditions Typ. Unit IVBAT OFF state Power down 10 uA Sleep state AT+CFUN=0 (USB disconnected) 1.15 mA WCDMA PF=64 (USB disconnected) 2.06 mA WCDMA PF=128 (USB disconnected) 1.65 mA LTE-FDD PF=64 (USB disconnected) 2.46 mA LTE-FDD PF=128 (USB disconnected) 1.86 mA Idle state (GNSS OFF) WCDMA PF=64 (USB disconnected) 22.0 mA WCDMA PF=64 (USB connected) 32.0 mA LTE-FDD PF=64 (USB disconnected) 23.5 mA LTE-FDD PF=64 (USB connected) 33.5 mA WCDMA data transfer (GNSS OFF) WCDMA B1 HSDPA @22.59dBm 623.0 mA WCDMA B1 HSUPA @22.47dBm 628.0 mA WCDMA B5 HSDPA @22.95dBm 605.0 mA
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 84 / 105 Table 39: EC21-J Current Consumption WCDMA B5 HSUPA @22.87dBm 610.0 mA WCDMA B8 HSDPA @22.37dBm 549.0 mA WCDMA B8 HSUPA @22.09dBm 564.0 mA LTE data transfer (GNSS OFF) LTE-FDD B1 @23.28dBm 789.0 mA LTE-FDD B3 @23.2dBm 768.0 mA LTE-FDD B5 @23.05dBm 669.0 mA LTE-FDD B8 @23.21dBm 693.0 mA LTE-FDD B28 @22.9dBm 795.0 mA WCDMA voice call WCDMA B1 @23.43dBm 672.0 mA WCDMA B5 @23.32dBm 616.0 mA WCDMA B8 @23.31dBm 592.0 mA Parameter Description Conditions Typ. Unit IVBAT OFF state Power down 10 uA Sleep state AT+CFUN=0 (USB disconnected) 0.85 mA LTE-FDD PF=64 (USB disconnected) 2.20 mA LTE-FDD PF=128 (USB disconnected) 1.46 mA Idle state (GNSS OFF) LTE-FDD PF=64 (USB disconnected) 23.5 mA LTE-FDD PF=64 (USB connected) 33.8 mA LTE data transfer (GNSS OFF) LTE-FDD B1 @23.35dBm 734.0 mA LTE-FDD B3 @22.95dBm 778.0 mA LTE-FDD B8 @22.81dBm 722.0 mA LTE-FDD B18 @23.15dBm 677.0 mA LTE-FDD B19 @23.17dBm 688.0 mA LTE-FDD B26 @23.37dBm 723.0 mA
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 85 / 105 Table 40: EC21-KL Current Consumption Table 41: GNSS Current Consumption of EC21 Series Module 6.5. RF Output Power The following table shows the RF output power of EC21 module. Parameter Description Conditions Typ. Unit IVBAT OFF state Power down 10 uA Sleep state AT+CFUN=0 (USB disconnected) 1.08 mA LTE-FDD PF=64 (USB disconnected) 2.1 mA LTE-FDD PF=128 (USB disconnected) 1.4 mA Idle state (GNSS OFF) LTE-FDD PF=64 (USB disconnected) 24.8 mA LTE-FDD PF=64 (USB connected) 33.5 mA LTE data transfer (GNSS OFF) LTE-FDD B1 @23.0dBm 771.0 mA LTE-FDD B3 @23.36dBm 780.0 mA LTE-FDD B5 @23.56dBm 628.0 mA LTE-FDD B7 @23.32dBm 754.0 mA LTE-FDD B8 @23.33dBm 680.0 mA Parameter Description Conditions Typ. Unit IVBAT (GNSS) Searching (AT+CFUN=0) Cold start @Passive Antenna 58 mA Lost state @Passive Antenna 58 mA Tracking (AT+CFUN=0) Instrument Environment 33 mA Open Sky @Passive Antenna 35 mA Open Sky @Active Antenna 43 mA
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 86 / 105 Table 42: RF Output Power Frequency Max. Min. GSM850/GSM900 33dBm±2dB 5dBm±5dB DCS1800/PCS1900 30dBm±2dB 0dBm±5dB GSM850/GSM900 (8-PSK) 27dBm±3dB 5dBm±5dB DCS1800/PCS1900 (8-PSK) 26dBm±3dB 0dBm±5dB WCDMA bands 24dBm+1/-3dB <-49dBm LTE-FDD bands 23dBm±2dB <-39dBm LTE-TDD bands 23dBm±2dB <-39dBm In GPRS 4 slots TX mode, the maximum output power is reduced by 3.0dB. The design conforms to the GSM specification as described in Chapter 13.16 of 3GPP TS 51.010-1. 6.6. RF Receiving Sensitivity The following tables show the conducted RF receiving sensitivity of EC21 series module. Table 43: EC21-E Conducted RF Receiving Sensitivity Frequency Primary Diversity SIMO1) 3GPP (SIMO) GSM900 -109.0dBm / / -102.0dBm DCS1800 -109.0dBm / / -102.0dbm WCDMA Band 1 -110.5dBm / / -106.7dBm WCDMA Band 5 -110.5dBm / / -104.7dBm WCDMA Band 8 -110.5dBm / / -103.7dBm LTE-FDD B1 (10M) -98.0dBm -98.0dBm -101.5dBm -96.3dBm LTE-FDD B3 (10M) -96.5dBm -98.5dBm -101.5dBm -93.3dBm NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 87 / 105 LTE-FDD B5 (10M) -98.0dBm -98.5dBm -101.0dBm -94.3dBm LTE-FDD B7 (10M) -97.0dBm -94.5dBm -99.5dBm -94.3dBm LTE-FDD B8 (10M) -97.0dBm -97.0dBm -101.0dBm -93.3dBm LTE-FDD B20 (10M) -97.5dBm -99.0dBm -102.5dBm -93.3dBm Table 44: EC21-A Conducted RF Receiving Sensitivity Frequency Primary Diversity SIMO1) 3GPP (SIMO) WCDMA B2 -110.0dBm / / -104.7dBm WCDMA B4 -110.0dBm / / -106.7dBm WCDMA B5 -110.5dBm / / -104.7dBm LTE-FDD B2 (10M) -98.0dBm -98.0dBm -101.0dBm -94.3dBm LTE-FDD B4 (10M) -97.5dBm -99.0dBm -101.0dBm -96.3dBm LTE-FDD B12 (10M) -96.5dBm -98.0dBm -101.0dBm -93.3dBm Table 45: EC21-V Conducted RF Receiving Sensitivity Frequency Primary Diversity SIMO1) 3GPP (SIMO) LTE-FDD B4 (10M) -97.5dBm -99.0dBm -101.0dBm -96.3dBm LTE-FDD B13 (10M) -95.0dBm -97.0dBm -100.0dBm -93.3dBm Table 46: EC21-AUT Conducted RF Receiving Sensitivity Frequency Primary Diversity SIMO1) 3GPP (SIMO) WCDMA B1 -110.0dBm / / -106.7dBm WCDMA B5 -110.5dBm / / -104.7dBm LTE-FDD B1 (10M) -98.5dBm -98.0dBm -101.0dBm -96.3dBm LTE-FDD B3 (10M) -98.0dBm -96.0dBm -100.0dBm -93.3dBm
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 88 / 105 LTE-FDD B5 (10M) -98.0dBm -99.0dBm -102.5dBm -94.3dBm LTE-FDD B7 (10M) -97.0dBm -95.0dBm -98.5dBm -94.3dBm LTE-FDD B28 (10M) -97.0dBm -99.0dBm -102.0dBm -94.8dBm Table 47: EC21-KL Conducted RF Receiving Sensitivity Frequency Primary Diversity SIMO1) 3GPP (SIMO) LTE-FDD B1 (10M) -98.0dBm -99.5dBm -100.5dBm -96.3dBm LTE-FDD B3 (10M) -97.0dBm -97.5dBm -99.5dBm -93.3dBm LTE-FDD B5 (10M) -98.0dBm -99.5dBm -100.5dBm -94.3dBm LTE-FDD B7 (10M) -96.0dBm -96.0dBm -98.5dBm -94.3dBm LTE-FDD B8 (10M) -97.0dBm -99.0dBm -101.0dBm -93.3dBm Table 48: EC21-J Conducted RF Receiving Sensitivity Table 49: EC21-AUV Conducted RF Receiving Sensitivity Frequency Primary Diversity SIMO1) 3GPP (SIMO) LTE-FDD B1 (10M) -97.5dBm -98.7dBm -100.2dBm -96.3dBm LTE-FDD B3 (10M) -96.5dBm -97.1dBm -100.5dBm -93.3dBm LTE-FDD B8 (10M) -98.4dBm -99.0dBm -101.2dBm -93.3dBm LTE-FDD B18 (10M) -99.5dBm -99.0dBm -101.7dBm -96.3dBm LTE-FDD B19 (10M) -99.2dBm -99.0dBm -101.4dBm -96.3dBm LTE-FDD B26 (10M) -99.5dBm -99.0dBm -101.5dBm -93.8dBm Frequency Primary Diversity SIMO1) 3GPP (SIMO) WCDMA B1 -109.5dBm / / -106.7dBm WCDMA B5 -111.0dBm / / -104.7dBm
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 89 / 105 Table 50: EC21-AU Conducted RF Receiving Sensitivity WCDMA B8 -111.0dBm / / -103.7dBm LTE-FDD B1 (10M) -97.7dBm -97.5dBm -101.3dBm -96.3dBm LTE-FDD B3 (10M) -98.2dBm -98.6dBm -102.7dBm -93.3dBm LTE-FDD B5 (10M) -98.7dBm -98.2dBm -102.5dBm -94.3dBm LTE-FDD B8 (10M) -98.2dBm -98.2dBm -102.3dBm -93.3dBm LTE-FDD B28 (10M) -98.0dBm -98.7dBm -102.1dBm -94.8dBm Frequency Primary Diversity SIMO1) 3GPP (SIMO) GSM850 -109.0dBm / / -102.0dBm GSM900 -109.0dBm / / -102.0dBm DCS1800 -109.0dBm / / -102.0dBm PCS1900 -109.0dBm / / -102.0dBm WCDMA B1 -110.0dBm / / -106.7dBm WCDMA B2 -110.0dBm / / -104.7dBm WCDMA B5 -111.0dBm / / -104.7dBm WCDMA B8 -111.0dBm / / -103.7dBm LTE-FDD B1 (10M) -97.2dBm -97.5dBm -100.2dBm -96.3dBm LTE-FDD B2 (10M) -98.2dBm / / -94.3dBm LTE-FDD B3 (10M) -98.7dBm -98.6dBm -102.2dBm -93.3dBm LTE-FDD B4 (10M) -97.7dBm -97.4dBm -100.2dBm -96.3dBm LTE-FDD B5 (10M) -98.0dBm -98.2dBm -101.0dBm -94.3dBm LTE-FDD B7 (10M) -97.7dBm -97.7dBm -101.2dBm -94.3dBm LTE-FDD B8 (10M) -99.2dBm -98.2dBm -102.2dBm -93.3dBm LTE-FDD B28 (10M) -98.6dBm -98.7dBm -102.0dBm -94.8dBm
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 90 / 105 1) SIMO is a smart antenna technology that uses a single antenna at the transmitter side and two antennas at the receiver side, which can improve RX performance. 6.7. Electrostatic Discharge The module is not protected against electrostatic discharge (ESD) in general. Consequently, it is subject to ESD handling precautions that typically apply to ESD sensitive components. Proper ESD handling and packaging procedures must be applied throughout the processing, handling and operation of any application that incorporates the module. The following table shows the module’s electrostatic discharge characteristics. Table 51: Electrostatic Discharge Characteristics Tested Points Contact Discharge Air Discharge Unit VBAT, GND ±5 ±10 kV All Antenna Interfaces ±4 ±8 kV Other Interfaces ±0.5 ±1 kV 6.8. Thermal Consideration In order to achieve better performance of the module, it is recommended to comply with the following principles for thermal consideration:  On customers’ PCB design, please keep placement of the module away from heating sources, especially high power components such as ARM processor, audio power amplifier, power supply, etc.  Do not place components on the opposite side of the PCB area where the module is mounted, in order to facilitate adding of heatsink when necessary.  Do not apply solder mask on the opposite side of the PCB area where the module is mounted, so as to ensure better heat dissipation performance.  The reference ground of the area where the module is mounted should be complete, and add ground vias as many as possible for better heat dissipation. LTE-TDD B40 (10M) -97.2dBm -98.4dBm -101.2dBm -96.3dBm NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 91 / 105  Make sure the ground pads of the module and PCB are fully connected.  According to customers’ application demands, the heatsink can be mounted on the top of the module, or the opposite side of the PCB area where the module is mounted, or both of them.  The heatsink should be designed with as many fins as possible to increase heat dissipation area. Meanwhile, a thermal pad with high thermal conductivity should be used between the heatsink and module/PCB. The following shows two kinds of heatsink designs for reference and customers can choose one or both of them according to their application structure. Figure 41: Referenced Heatsink Design (Heatsink at the Top of the Module) Figure 42: Referenced Heatsink Design (Heatsink at the Bottom of Customers’ PCB)
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 92 / 105 The module offers the best performance when the internal BB chip stays below 105°C. When the maximum temperature of the BB chip reaches or exceeds 105°C, the module works normal but provides reduced performance (such as RF output power, data rate, etc.). When the maximum BB chip temperature reaches or exceeds 115°C, the module will disconnect from the network, and it will recover to network connected state after the maximum temperature falls below 115°C. Therefore, the thermal design should be maximally optimized to make sure the maximum BB chip temperature always maintains below 105°C. Customers can execute AT+QTEMP command and get the maximum BB chip temperature from the first returned value. NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 93 / 105 7 Mechanical Dimensions This chapter describes the mechanical dimensions of the module. All dimensions are measured in mm. The tolerances for dimensions without tolerance values are ±0.05mm. 7.1. Mechanical Dimensions of the Module 32.0±0.1529.0±0.150.82.4±0.2 Figure 43: Module Top and Side Dimensions
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 94 / 105 Figure 44: Module Bottom Dimensions (Bottom View)
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 95 / 105 7.2. Recommended Footprint Figure 45: Recommended Footprint (Top View) 1. The keep out area should not be designed. 2. For easy maintenance of the module, please keep about 3mm between the module and other components in the host PCB. NOTES
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 96 / 105 7.3. Design Effect Drawings of the Module Figure 46: Top View of the Module Figure 47: Bottom View of the Module These are design effect drawings of EC21 module. For more accurate pictures, please refer to the module that you get from Quectel. NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 97 / 105 8 Storage, Manufacturing and Packaging 8.1. Storage EC21 is stored in a vacuum-sealed bag. The storage restrictions are shown as below. 1. Shelf life in the vacuum-sealed bag: 12 months at <40ºC/90%RH. 2. After the vacuum-sealed bag is opened, devices that will be subjected to reflow soldering or other high temperature processes must be:  Mounted within 168 hours at the factory environment of ≤30ºC/60%RH  Stored at <10%RH 3. Devices require baking before mounting, if any circumstances below occurs:  When the ambient temperature is 23ºC±5ºC and the humidity indicator card shows the humidity is >10% before opening the vacuum-sealed bag.  Device mounting cannot be finished within 168 hours at factory conditions of ≤30ºC/60%RH. 4. If baking is required, devices may be baked for 8 hours at 120ºC±5ºC. As the plastic package cannot be subjected to high temperature, it should be removed from devices before high temperature (120ºC) baking. If shorter baking time is desired, please refer to IPC/JEDECJ-STD-033 for baking procedure. NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 98 / 105 8.2. Manufacturing and Soldering Push the squeegee to apply the solder paste on the surface of stencil, thus making the paste fill the stencil openings and then penetrate to the PCB. The force on the squeegee should be adjusted properly so as to produce a clean stencil surface on a single pass. To ensure the module soldering quality, the thickness of stencil for the module is recommended to be 0.20mm. For more details, please refer to document [4]. It is suggested that the peak reflow temperature is 235ºC~245ºC (for SnAg3.0Cu0.5 alloy). The absolute maximum reflow temperature is 260ºC. To avoid damage to the module caused by repeated heating, it is suggested that the module should be mounted after reflow soldering for the other side of PCB has been completed. Recommended reflow soldering thermal profile is shown below: Figure 48: Reflow Soldering Thermal Profile During manufacturing and soldering, or any other processes that may contact the module directly, NEVER wipe the module label with organic solvents, such as acetone, ethyl alcohol, isopropyl alcohol, trichloroethylene, etc. NOTE
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 99 / 105 8.3. Packaging EC21 is packaged in tape and reel carriers. One reel is 11.88m long and contains 250pcs modules. The figure below shows the packaging details, measured in mm. 30.3± 0.1529.3± 0.1530.3± 0.1532.5± 0.1533.5± 0.150.35± 0.054.2± 0.153.1± 0.1532.5± 0.1533.5± 0.154.00± 0.12.00±0.11.75± 0.120.20± 0.1544.00± 0.344.00±0.11.50±0.1 1310044.5+0.20-0.0048.5 Figure 49: Tape and Reel Specifications
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 100 / 105 9 Appendix A References Table 52: Related Documents SN Document Name Remark [1] Quectel_EC2x&EG9x&EM05_Power_Management_ Application_Note Power management application notefor EC25, EC21, EC20 R2.0, EC20 R2.1, EG95, EG91 and EM05 modules [2] Quectel_EC25&EC21_AT_Commands_Manual EC25 and EC21 AT commands manual [3] Quectel_EC25&EC21_GNSS_AT_Commands_Manual EC25 and EC21 GNSS AT commands manual [4] Quectel_Module_Secondary_SMT_User_Guide Module secondary SMT user guide [5] Quectel_EC21_Reference_Design EC21 reference design [6] Quectel_RF_Layout_Application_Note RF layout application note Table 53: Terms and Abbreviations Abbreviation Description AMR Adaptive Multi-rate bps Bits Per Second CHAP Challenge Handshake Authentication Protocol CS Coding Scheme CSD Circuit Switched Data CTS Clear To Send DC-HSPA+ Dual-carrier High Speed Packet Access DFOTA Delta Firmware Upgrade Over The Air DL Downlink
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 101 / 105 DTR Data Terminal Ready DTX Discontinuous Transmission EFR Enhanced Full Rate ESD Electrostatic Discharge FDD Frequency Division Duplex FR Full Rate GLONASS GLObalnaya NAvigatsionnaya Sputnikovaya Sistema, the Russian Global Navigation Satellite System GMSK Gaussian Minimum Shift Keying GNSS Global Navigation Satellite System GPS Global Positioning System GSM Global System for Mobile Communications HR Half Rate HSPA High Speed Packet Access HSDPA High Speed Downlink Packet Access HSUPA High Speed Uplink Packet Access I/O Input/Output Inorm Normal Current LED Light Emitting Diode LNA Low Noise Amplifier LTE Long Term Evolution MIMO Multiple Input Multiple Output MO Mobile Originated MS Mobile Station (GSM engine) MT Mobile Terminated PAP Password Authentication Protocol
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 102 / 105 PCB Printed Circuit Board PDU Protocol Data Unit PPP Point-to-Point Protocol QAM Quadrature Amplitude Modulation QPSK Quadrature Phase Shift Keying RF Radio Frequency RHCP Right Hand Circularly Polarized Rx Receive SGMII Serial Gigabit Media Independent Interface SIM Subscriber Identification Module SIMO Single Input Multiple Output SMS Short Message Service TDD Time Division Duplexing TDMA Time Division Multiple Access TD-SCDMA Time Division-Synchronous Code Division Multiple Access TX Transmitting Direction UL Uplink UMTS Universal Mobile Telecommunications System URC Unsolicited Result Code USIM Universal Subscriber Identity Module Vmax Maximum Voltage Value Vnorm Normal Voltage Value Vmin Minimum Voltage Value VIHmax Maximum Input High Level Voltage Value VIHmin Minimum Input High Level Voltage Value
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 103 / 105 VILmax Maximum Input Low Level Voltage Value VILmin Minimum Input Low Level Voltage Value VImax Absolute Maximum Input Voltage Value VImin Absolute Minimum Input Voltage Value VOHmax Maximum Output High Level Voltage Value VOHmin Minimum Output High Level Voltage Value VOLmax Maximum Output Low Level Voltage Value VOLmin Minimum Output Low Level Voltage Value VSWR Voltage Standing Wave Ratio WCDMA Wideband Code Division Multiple Access WLAN Wireless Local Area Network
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 104 / 105 10 Appendix B GPRS Coding Schemes Table 54: Description of Different Coding Schemes Scheme CS-1 CS-2 CS-3 CS-4 Code Rate 1/2 2/3 3/4 1 USF 3 3 3 3 Pre-coded USF 3 6 6 12 Radio Block excl. USF and BCS 181 268 312 428 BCS 40 16 16 16 Tail 4 4 4 - Coded Bits 456 588 676 456 Punctured Bits 0 132 220 - Data Rate Kb/s 9.05 13.4 15.6 21.4
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 105 / 105 11 Appendix C GPRS Multi-slot Classes Twenty-nine classes of GPRS multi-slot modes are defined for MS in GPRS specification. Multi-slot classes are product dependent, and determine the maximum achievable data rates in both the uplink and downlink directions. Written as 3+1 or 2+2, the first number indicates the amount of downlink timeslots, while the second number indicates the amount of uplink timeslots. The active slots determine the total number of slots the GPRS device can use simultaneously for both uplink and downlink communications. The description of different multi-slot classes is shown in the following table. Table 55: GPRS Multi-slot Classes Multislot Class Downlink Slots Uplink Slots Active Slots 1 1 1 2 2 2 1 3 3 2 2 3 4 3 1 4 5 2 2 4 6 3 2 4 7 3 3 4 8 4 1 5 9 3 2 5 10 4 2 5 11 4 3 5 12 4 4 5 13 3 3 NA 14 4 4 NA
LTE Module Series EC21 Hardware Design EC21_Hardware_Design 106 / 105 15 5 5 NA 16 6 6 NA 17 7 7 NA 18 8 8 NA 19 6 2 NA 20 6 3 NA 21 6 4 NA 22 6 4 NA 23 6 6 NA 24 8 2 NA 25 8 3 NA 26 8 4 NA 27 8 4 NA 28 8 6 NA 29 8 8 NA 30 5 1 6 31 5 2 6 32 5 3 6 33 5 4 6
LTE Module Sires EC21 Hardware Design EC21_Hardware_Design 107 / 105 12 Appendix D EDGE Modulation and Coding Schemes Table 56: EDGE Modulation and Coding Schemes Coding Scheme Modulation Coding Family 1 Timeslot 2 Timeslot 4 TimeslotCS-1: GMSK / 9.05kbps 18.1kbps 36.2kbps CS-2: GMSK / 13.4kbps 26.8kbps 53.6kbps CS-3: GMSK / 15.6kbps 31.2kbps 62.4kbps CS-4: GMSK / 21.4kbps 42.8kbps 85.6kbps MCS-1 GMSK C 8.80kbps 17.60kbps 35.20kbps MCS-2 GMSK B 11.2kbps 22.4kbps 44.8kbps MCS-3 GMSK A 14.8kbps 29.6kbps 59.2kbps MCS-4 GMSK C 17.6kbps 35.2kbps 70.4kbps MCS-5 8-PSK B 22.4kbps 44.8kbps 89.6kbps MCS-6 8-PSK A 29.6kbps 59.2kbps 118.4kbps MCS-7 8-PSK B 44.8kbps 89.6kbps 179.2kbps MCS-8 8-PSK A 54.4kbps 108.8kbps 217.6kbps MCS-9 8-PSK A 59.2kbps 118.4kbps 236.8kbps
EC21 Mini PCIe Hardware Design LTE Module Series Rev. EC21_Mini_PCIe_Hardware_Design_V1.1 Date: 2017-01-24 www.quectel.com
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 1 / 41 Our aim is to provide customers with timely and comprehensive service. For any assistance, please contact our company headquarters: Quectel Wireless Solutions Co., Ltd. Office 501, Building 13, No.99, Tianzhou Road, Shanghai, China, 200233 Tel: +86 21 5108 6236 Email: info@quectel.com Or our local office. For more information, please visit: http://www.quectel.com/support/salesupport.aspx For technical support, or to report documentation errors, please visit: http://www.quectel.com/support/techsupport.aspx Or email to: Support@quectel.com GENERAL NOTES QUECTEL OFFERS THE INFORMATION AS A SERVICE TO ITS CUSTOMERS. THE INFORMATION PROVIDED IS BASED UPON CUSTOMERS’ REQUIREMENTS. QUECTEL MAKES EVERY EFFORT TO ENSURE THE QUALITY OF THE INFORMATION IT MAKES AVAILABLE. QUECTEL DOES NOT MAKE ANY WARRANTY AS TO THE INFORMATION CONTAINED HEREIN, AND DOES NOT ACCEPT ANY LIABILITY FOR ANY INJURY, LOSS OR DAMAGE OF ANY KIND INCURRED BY USE OF OR RELIANCE UPON THE INFORMATION. THE INFORMATION SUPPLIED HEREIN IS SUBJECT TO CHANGE WITHOUT PRIOR NOTICE. COPYRIGHT THE INFORMATION CONTAINED HERE IS PROPRIETARY TECHNICAL INFORMATION OF QUECTEL CO., LTD. TRANSMITTING, REPRODUCTION, DISSEMINATION AND EDITING OF THIS DOCUMENT AS WELL AS UTILIZATION OF THE CONTENT ARE FORBIDDEN WITHOUT PERMISSION. OFFENDERS WILL BE HELD LIABLE FOR PAYMENT OF DAMAGES. ALL RIGHTS ARE RESERVED IN THE EVENT OF A PATENT GRANT OR REGISTRATION OF A UTILITY MODEL OR DESIGN. Copyright © Quectel Wireless Solutions Co., Ltd. 2017. All rights reserved.
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 2 / 41 About the Document History Revision Date Author Description 1.0 2016-06-07 Yeoman CHEN/ Frank WANG Initial 1.1 2017-01-24 Lyndon LIU/ Rex WANG 1. Deleted description of EC21-AUTL and EC21-CT Mini PCIe in Table 1. 2. Updated key features of EC21 Mini PCIe in Table 2. 3. Added current consumption of EC21 Mini PCIe in Chapter 4.7. 4. Updated mechanical dimensions of EC21 Mini PCIe in Figure 15. 5. Updated conducted RF output power in Table 16. 6. Updated conducted RF receiving sensitivity of EC21-A in Table 18. 7. Added conducted RF receiving sensitivity of EC21-KL in Table 21. 8. Added conducted RF receiving sensitivity of EC21-J in Table 22.
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 3 / 41 Contents About the Document ................................................................................................................................ 2Contents .................................................................................................................................................... 3Table Index ............................................................................................................................................... 5Figure Index .............................................................................................................................................. 61Introduction ....................................................................................................................................... 71.1.Safety Information ................................................................................................................... 81.2.FCC Statement ....................................................................................................................... 92Product Concept ............................................................................................................................. 112.1.General Description ...............................................................................................................112.2.Description of Product Series ................................................................................................ 122.3.Key Features ......................................................................................................................... 132.4.Functional Diagram ............................................................................................................... 153Application Interface ....................................................................................................................... 163.1.General Description .............................................................................................................. 163.2.EC21 Mini PCIe Interface ...................................................................................................... 163.2.1.Definition of Interface ................................................................................................... 163.2.2.Pin Assignment ............................................................................................................ 193.3.Power Supply ........................................................................................................................ 203.4.USIM Card Interface ............................................................................................................. 213.5.USB Interface ........................................................................................................................ 223.6.UART Interface ..................................................................................................................... 233.7.PCM and I2C Interfaces ........................................................................................................ 243.8.Control Signals ...................................................................................................................... 263.8.1.RI Signal ...................................................................................................................... 273.8.2.DTR Signal .................................................................................................................. 273.8.3.W_DISABLE# Signal ................................................................................................... 273.8.4.PERST# Signal ............................................................................................................ 273.8.5.LED_WWAN# Signal ................................................................................................... 283.8.6.WAKE# Signal ............................................................................................................. 293.9.Antenna Interfaces ................................................................................................................ 294Electrical and Radio Characteristics ............................................................................................. 314.1.General Description .............................................................................................................. 314.2.Power Supply Requirements ................................................................................................. 314.3.I/O Requirements .................................................................................................................. 324.4.RF Characteristics ................................................................................................................ 324.5.GNSS Receiver ..................................................................................................................... 354.6.ESD Characteristics .............................................................................................................. 354.7.Current Consumption ............................................................................................................ 36
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 4 / 41 5Dimensions and Packaging ............................................................................................................ 395.1.General Description .............................................................................................................. 395.2.Mechanical Dimensions of EC21 Mini PCIe .......................................................................... 395.3.Standard Dimensions of Mini PCI Express ............................................................................ 405.4.Packaging Specification ........................................................................................................ 416Appendix References ..................................................................................................................... 42
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 5 / 41 Table Index TABLE 1: DESCRIPTION OF EC21 MINI PCIE ................................................................................................ 12TABLE 2: KEY FEATURES OF EC21 MINI PCIE ............................................................................................. 13TABLE 3: DEFINITION OF I/O PARAMETERS ................................................................................................. 16TABLE 4: DESCRIPTION OF PINS .................................................................................................................. 17TABLE 5: DEFINITION OF VCC_3V3 AND GND PINS .................................................................................... 20TABLE 6: USIM PIN DEFINITION ..................................................................................................................... 21TABLE 7: PIN DEFINITION OF USB INTERFACE ........................................................................................... 22TABLE 8: PIN DEFINITION OF THE UART INTERFACE ................................................................................. 23TABLE 9: PIN DEFINITION OF PCM AND I2C INTERFACES ......................................................................... 24TABLE 10: PIN DEFINITION OF CONTROL SIGNAL ...................................................................................... 26TABLE 11: RADIO OPERATIONAL STATES ..................................................................................................... 27TABLE 12: INDICATIONS OF NETWORK STATUS ......................................................................................... 28TABLE 13: ANTENNA REQUIREMENTS .......................................................................................................... 29TABLE 14: POWER SUPPLY REQUIREMENTS .............................................................................................. 31TABLE 15: I/O REQUIREMENTS ...................................................................................................................... 32TABLE 16: EC21 MINI PCIE CONDUCTED RF OUTPUT POWER ................................................................. 32TABLE 17: EC21-E MINI PCIE CONDUCTED RF RECEIVING SENSITIVITY ................................................ 33TABLE 18: EC21-A MINI PCIE CONDUCTED RF RECEIVING SENSITIVITY ................................................ 33TABLE 19: EC21-V MINI PCIE CONDUCTED RF RECEIVING SENSITIVITY ................................................ 34TABLE 20: EC21-AUT MINI PCIE CONDUCTED RF RECEIVING SENSITIVITY ........................................... 34TABLE 21: EC21-KL MINI PCIE CONDUCTED RF RECEIVING SENSITIVITY .............................................. 34TABLE 22: EC21-J MINI PCIE CONDUCTED RF RECEIVING SENSITIVITY ................................................ 35TABLE 23: ESD CHARACTERISTICS OF EC21 MINI PCIE ............................................................................ 35TABLE 24: CURRENT CONSUMPTION OF EC21-A MINI PCIE ..................................................................... 36TABLE 25: CURRENT CONSUMPTION OF EC21-V MINI PCIE ..................................................................... 37TABLE 26: CURRENT CONSUMPTION OF EC21-KL MINI PCIE ................................................................... 37TABLE 27: GNSS CURRENT CONSUMPTION OF EC21 MINI PCIE SERIES MODULE ............................... 38TABLE 28: RELATED DOCUMENTS ................................................................................................................ 42TABLE 29: TERMS AND ABBREVIATIONS ...................................................................................................... 42
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 6 / 41 Figure Index FIGURE 1: FUNCTIONAL DIAGRAM ............................................................................................................... 15FIGURE 2: PIN ASSIGNMENT ......................................................................................................................... 19FIGURE 3: REFERENCE DESIGN OF POWER SUPPLY ............................................................................... 20FIGURE 4: REFERENCE CIRCUIT OF USIM CARD INTERFACE WITH A 6-PIN USIM CARD CONNECTOR ........................................................................................................................................................................... 21FIGURE 5: REFERENCE CIRCUIT OF USB INTERFACE .............................................................................. 22FIGURE 6: TIMING IN PRIMARY MODE .......................................................................................................... 25FIGURE 7: TIMING IN AUXILIARY MODE ....................................................................................................... 25FIGURE 8: REFERENCE CIRCUIT OF PCM APPLICATION WITH AUDIO CODEC ...................................... 26FIGURE 9: RI BEHAVIOR ................................................................................................................................. 27FIGURE 10: TIMING OF RESETTING MODULE ............................................................................................. 28FIGURE 11: LED_WWAN# SIGNAL REFERENCE CIRCUIT DIAGRAM ......................................................... 28FIGURE 12: WAKE# BEHAVIOR ...................................................................................................................... 29FIGURE 13: DIMENSIONS OF THE RF CONNECTOR (UNIT: MM) ............................................................... 30FIGURE 14: MECHANICALS OF UF.L-LP CONNECTORS ............................................................................. 30FIGURE 15: MECHANICAL DIMENSIONS OF EC21 MINI PCIE (UNIT: MM) ................................................. 39FIGURE 16: STANDARD DIMENSIONS OF MINI PCI EXPRESS (UNIT: MM) ............................................... 40FIGURE 17: DIMENSIONS OF THE MINI PCI EXPRESS CONNECTOR (THE MOLEX 679100002, UNIT: MM) ........................................................................................................................................................................... 41
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 7 / 41 1 Introduction This document defines EC21 Mini PCIe module and describes its hardware interfaces which are connected with your application and air interfaces. This document can help you to quickly understand the interface specifications, electrical and mechanical details and related product information of the EC21 Mini PCIe module. To facilitate its application in different fields, relevant reference design documents are also provided. Associated with application note and user guide of EC21 Mini PCIe module, you can use the module to design and set up mobile applications easily.
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 8 / 41 1.1. Safety Information The following safety precautions must be observed during all phases of the operation, such as usage, service or repair of any cellular terminal or mobile incorporating EC21 Mini PCIe module. Manufacturers of the cellular terminal should send the following safety information to users and operating personnel, and incorporate these guidelines into all manuals supplied with the product. If not so, Quectel does not take on any liability for customer failure to comply with these precautions. Full attention must be given to driving at all times in order to reduce the risk of an accident. Using a mobile while driving (even with a handsfree kit) causes distraction and can lead to an accident. You must comply with laws and regulations restricting the use of wireless devices while driving. Switch off the cellular terminal or mobile before boarding an aircraft. Make sure it is switched off. The operation of wireless appliances in an aircraft is forbidden, so as to prevent interference with communication systems. Consult the airline staff about the use of wireless devices on boarding the aircraft, if your device offers an Airplane Mode which must be enabled prior to boarding an aircraft. Switch off your wireless device when in hospitals, clinics or other health care facilities. These requests are desinged to prevent possible interference with sensitive medical equipment. Cellular terminals or mobiles operating over radio frequency signal and cellular network cannot be guaranteed to connect in all conditions, for example no mobile fee or with an invalid USIM/SIM card. While you are in this condition and need emergent help, please remember using emergency call. In order to make or receive a call, the cellular terminal or mobile must be switched on and in a service area with adequate cellular signal strength. Your cellular terminal or mobile contains a transmitter and receiver. When it is ON, it receives and transmits radio frequency energy. RF interference can occur if it is used close to TV set, radio, computer or other electric equipment. In locations with potentially explosive atmospheres, obey all posted signs to turn off wireless devices such as your phone or other cellular terminals. Areas with potentially explosive atmospheres include fuelling areas, below decks on boats, fuel or chemical transfer or storage facilities, areas where the air contains chemicals or particles such as grain, dust or metal powders, etc.
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 9 / 41 1.2. FCC Statement According to the definition of mobile and fixed device is described in Part 2.1091(b), this device is a mobile device. And the following conditions must be met: 1. This Modular Approval is limited to OEM installation for mobile and fixed applications only. The antenna installation and operating configurations of this transmitter, including any applicable source-based time- averaging duty factor, antenna gain and cable loss must satisfy MPE categorical Exclusion Requirements of 2.1091. 2. The EUT is a mobile device; maintain at least a 20 cm separation between the EUT and the user’s body and must not transmit simultaneously with any other antenna or transmitter. 3.A label with the following statements must be attached to the host end product: This device contains FCC ID: XMR201805EC21AU. 4.To comply with FCC regulations limiting both maximum RF output power and human exposure to RF radiation, maximum antenna gain (including cable loss) must not exceed 4dBi 5. This module must not transmit simultaneously with any other antenna or transmitter 6. The host end product must include a user manual that clearly defines operating requirements and conditions that must be observed to ensure compliance with current FCC RF exposure guidelines. For portable devices, in addition to the conditions 3 through 6 described above, a separate approval is required to satisfy the SAR requirements of FCC Part 2.1093 If the device is used for other equipment that separate approval is required for all other operating configurations, including portable configurations with respect to 2.1093 and different antenna configurations. For this device, OEM integrators must be provided with labeling instructions of finished products. Please refer to KDB784748 D01 v07, section 8. Page 6/7 last two paragraphs: A certified modular has the option to use a permanently affixed label, or an electronic label. For a permanently affixed label, the module must be labelled withan FCC ID - Section 2.926 (see 2.2 Certification (labelling requirements) above). The OEM manual must provide clear instructions explaining to the OEM the labelling requirements,options and OEM user manual instructions that are required (see next paragraph). For a host using a certified modular with a standard fixed label, if (1) the module’s FCC ID is notvisible when installed in the host, or (2) if the host is marketed so that end users do not havestraightforward commonly used methods for access to remove the module so that the FCC ID ofthe module is visible; then an additional permanent label referring to the enclosed module:“Contains Transmitter Module FCC ID:XMR201805EC21AU” or “Contains FCC ID: XMR201805EC21AU” mustbe used. The host OEM user manual must also contain clear instructions on how end users can find and/or access the module and the FCC ID. The final host / module combination may also need to be evaluated against the FCC Part 15B criteria for unintentional radiators in order to be properly authorized for operation as a Part 15 digital device. The user’s manual or instruction manual for an intentional or unintentional radiator shall caution the user that changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment. In cases where the manual is provided only in a form other than paper, such as on a computer disk or over the Internet, the information required by this section may be
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 10 / 41 included in the manual in that alternative form, provided the user can reasonably be expected to have the capability to access information in that form. This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Changes or modifications not expressly approved by the manufacturer could void the user’s authority to operate the equipment. To ensure compliance with all non-transmitter functions the host manufacturer is responsible for ensuring compliance with the module(s) installed and fully operational. For example, if a host was previously authorized as an unintentional radiator under the Declaration of Conformity procedure without a transmitter certified module and a module is added, the host manufacturer is responsible for ensuring that the after the module is installed and operational the host continues to be compliant with the Part 15B unintentional radiator requirements.
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 11 / 41 2 Product Concept 2.1. General Description EC21 Mini PCIe module provides data connectivity on LTE-FDD, LTE-TDD, WCDMA and GSM networks with PCI Express Mini Card 1.2 standard interface. It supports embedded operating systems such as WinCE, Linux and Android etc., and also provides audio, high-speed data transmission and GNSS functionality for your applications. EC21 Mini PCIe module can be applied in the following fields:  PDAs and Laptop Computer  Remote Monitor System  Vehicle System  Wireless POS System  Intelligent Meter Reading System  Wireless Router and Switch  Other Wireless Terminal Devices This chapter generally introduces the following aspects of EC21 Mini PCIe module:  Product Series  Key Features  Functional Diagram  EC21 Mini PCIe contains Telematics version and Data-only version. Telematics version supports voice and data functions, while Data-only version only supports data function. NOTE
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 12 / 41 2.2. Description of Product Series The following table shows the product series of EC21 Mini PCIe module. Table 1: Description of EC21 Mini PCIe Product Series Description EC21-E Mini PCIe Support GSM: 900/1800MHz Support WCDMA: B1/B5/B8 Support LTE-FDD: B1/B3/B5/B7/B8/B20 Support LTE/WCDMA receive diversity Support GNSS1) Support digital audio2) EC21-A Mini PCIe Support WCDMA: B2/B4/B5 Support LTE-FDD: B2/B4/B12 Support LTE/WCDMA receive diversity Support GNSS1) Support digital audio2) EC21-V Mini PCIe Support LTE-FDD: B4/B13 Support LTE receive diversity Support GNSS1) Support digital audio2) EC21-AUT Mini PCIe Support WCDMA: B1/B5 Support LTE-FDD: B1/B3/B5/B7/B28 Support LTE/WCDMA receive diversity Support GNSS1) Support digital audio2) EC21-AU Mini PCIe3) Support GSM: 850/900/1800/1900MHz Support WCDMA: B1/B2/B5/B8 Support LTE-FDD: B1/B2/B3/B4/B5/B7/B8/B28 Support LTE-TDD: B40 Support LTE/WCDMA receive diversity3) Support GNSS1) Support digital audio2) EC21-J Mini PCIe Support LTE-FDD: B1/B3/B8/B18/B19/B26 Support LTE receive diversity Support digital audio2) EC21-KL Mini PCIe Support LTE-FDD: B1/B3/B5/B7/B8 Support LTE receive diversity Support digital audio2)
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 13 / 41 1. 1) GNSS function is optional. 2. 2) Digital audio (PCM) function is only supported in Telematics version. 3. 3) B2 band on EC21-AU Mini PCIe module does not support receive diversity. 2.3. Key Features The following table describes the detailed features of EC21 Mini PCIe module. Table 2: Key Features of EC21 Mini PCIe Feature Details Function Interface PCI Express Mini Card 1.2 Standard Interface Power Supply Supply voltage: 3.0~3.6V Typical supply voltage: 3.3V Transmitting Power Class 4 (33dBm±2dB) for GSM850 Class 4 (33dBm±2dB) for GSM900 Class 1 (30dBm±2dB) for DCS1800 Class 1 (30dBm±2dB) for PCS1800 Class E2 (27dBm±3dB) for GSM850 8-PSK Class E2 (27dBm±3dB) for GSM900 8-PSK Class E2 (26dBm±3dB) for DCS1800 8-PSK Class E2 (26dBm±3dB) for PCS1900 8-PSK Class 3 (24dBm+1/-3dB) for WCDMA bands Class 3 (23dBm±2dB) for LTE-FDD bands Class 3 (23dBm±2dB) for LTE-TDD bands LTE Features Support up to non-CA Cat 1 Support 1.4 to 20MHz RF bandwidth Support MIMO in DL direction FDD: Max 5Mbps (UL), 10Mbps (DL) TDD: Max 3.1Mbps (UL), 8.96Mbps (DL) TDD: Max 3.1Mbps (UL), 8.96Mbps (DL) WCDMA Features Support 3GPP R8 DC-HSPA+ Support 16-QAM, 64-QAM and QPSK modulation 3GPP R6 Cat 6 HSUPA: Max 5.76Mbps (UL) 3GPP R8 Cat 24 DC-HSPA+: Max 42Mbps (DL) GSM Features R99: CSD: 9.6kbps, 14.4kbps GPRS: NOTES
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 14 / 41 Support GPRS multi-slot class 12 (12 by default) Coding scheme: CS-1, CS-2, CS-3 and CS-4 Maximum of four Rx time slots per frame EDGE: Support EDGE multi-slot class 12 (12 by default) Support GMSK and 8-PSK for different MCS (Modulation and Coding Scheme) Downlink coding schemes: CS 1-4 and MCS 1-9 Uplink coding schemes: CS 1-4 and MCS 1-9 Internet Protocol FeaturesSupport TCP/UDP/PPP/FTP/HTTP/NTP/PING/QMI/HTTPS*/SMTP*/ MMS*/FTPS*/SSL* protocols Support PAP (Password Authentication Protocol) and CHAP (Challenge Handshake Authentication Protocol) protocols usually used for PPP connections SMS Text and PDU mode Point to point MO and MT SMS cell broadcast SMS storage: ME by default USIM Interface Support USIM/SIM card: 1.8V, 3.0V UART Interface Baud rate can reach up to 230400bps; 115200bps by default Used for AT command communication Audio Feature Support one digital audio interface: PCM interface GSM: HR/FR/EFR/AMR/AMR-WB WCDMA: AMR/AMR-WB LTE: AMR/AMR-WB Support echo cancellation and noise suppression PCM Interface Support 8-bit A-law*, μ-law* and 16-bit linear data formats Support long frame synchronization and short frame synchronization Support master and slave mode, but must be the master in long frame synchronization USB Interface Compliant with USB 2.0 specification (slave only), the data transfer rate can reach up to 480Mbps Used for AT command communication, data transmission, firmware upgrade, software debugging, GNSS NMEA output and voice over USB* USB Driver: Windows XP, Windows Vista, Windows 7, Windows 8/8.1, Windows 10, Linux 2.6 or later, Android 4.0/4.2/4.4/5.0/5.1/6.0 Antenna Interface Include main antenna, diversity antenna and GNSS antenna Rx-diversity Support LTE/WCDMA Rx-diversity GNSS Features Gen 8C Lite of Qualcomm Protocol: NMEA 0183 AT Commands Compliant with 3GPP TS 27.007, 27.005 and Quectel enhanced AT commands
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 15 / 41 1. “*” means under development. 2. 2) Within operating temperature range, the module is 3GPP compliant. 3. 3) Within extended temperature range, the module remains the ability to establish and maintain a voice, SMS, data transmission, emergency call, etc. There is no unrecoverable malfunction; there are also no effects on radio spectrum and no harm to radio network. Only one or more parameters like Pout might reduce in their value and exceed the specified tolerances. When the temperature returns to normal operating temperature levels, the module is compliant with 3GPP specification again. 2.4. Functional Diagram The following figure shows the block diagram of EC21 Mini PCIe. Figure 1: Functional Diagram Physical Characteristics Size: (51.0±0.1) × (30.0±0.1) × (4.9±0.2) mm Weight: approx. 9.8g Temperature Range Operation temperature range: -35°C ~ +75°C2) Extended temperature range: -40°C ~ +80°C3) Firmware Upgrade USB interface and DFOTA* RoHS All hardware components are fully compliant with EU RoHS directive NOTES
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 16 / 41 3 Application Interface 3.1. General Description The physical connections and signal levels of EC21 Mini PCIe comply with PCI Express Mini CEM specifications. This chapter mainly describes the following interface definition and application of EC21 Mini PCIe:  Power supply  USIM card interface  USB interface  UART interface  PCM&I2C interfaces  Control signals  Antenna interface 3.2. EC21 Mini PCIe Interface 3.2.1. Definition of Interface The following tables show the pin definition and description of EC21 Mini PCIe on the 52-pin application. Table 3: Definition of I/O Parameters Type Description IO Bidirectional DI Digital input DO Digital output OC Open collector PI Power input PO Power output
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 17 / 41 Table 4: Description of Pins Pin No. Mini PCI Express Standard Name EC21 Mini PCIe Pin Name I/O Description Comment 1 WAKE# WAKE# OC Output signal can be used to wake up the host. 2 3.3Vaux VCC_3V3 PI 3.3V DC supply 3 COEX1 RESERVED Reserved 4 GND GND Mini card ground 5 COEX2 RESERVED Reserved 6 1.5V NC 7 CLKREQ# RESERVED Reserved 8 UIM_PWR USIM_VDD PO Power source for the USIM card 9 GND GND Mini card ground 10 UIM_DATA USIM_DATA IO USIM data signal 11 REFCLK- UART_RX DI UART receive data Connect to DTE’s TX 12 UIM_CLK USIM_CLK DO USIM clock signal 13 REFCLK+ UART_TX DO UART transmit data Connect to DTE’s RX 14 UIM_RESET USIM_RST DO USIM reset signal 15 GND GND Mini card ground 16 UIM_VPP RESERVED Reserved 17 RESERVED RI DO Output signal can be used to wake up the host. 18 GND GND Mini card ground 19 RESERVED RESERVED Reserved 20 W_DISABLE# W_DISABLE# DI Disable wireless communications Pull-up Active low 21 GND GND Mini card ground 22 PERST# PERST# DI Functional reset to the card Active low 23 PERn0 UART_CTS DI UART clear to send Connect to DTE’s RTS 24 3.3Vaux RESERVED Reserved
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 18 / 41 25 PERp0 UART_RTS DO UART request to send Connect to DTE’s CTS 26 GND GND Mini card ground 27 GND GND Mini card ground 28 1.5V NC 29 GND GND Mini card ground 30 SMB_CLK I2C_SCL DO I2C serial clock Require external pull-up to 1.8V. 31 PETn0 DTR DI Sleep mode control 32 SMB_DATA I2C_SDA IO I2C serial data Require external pull-up to 1.8V. 33 PETp0 RESERVED Reserved 34 GND GND Mini card ground 35 GND GND Mini card ground 36 USB_D- USB_DM IO USB differential data (-) 37 GND GND Mini card ground 38 USB_D+ USB_DP IO USB differential data (+) 39 3.3Vaux VCC_3V3 PI 3.3V DC supply 40 GND GND Mini card ground 41 3.3Vaux VCC_3V3 PI 3.3V DC supply 42 LED_WWAN# LED_WWAN# OC Active-low. LED signal for indicating the state of the card. 43 GND GND Mini card ground 44 LED_WLAN# RESERVED Reserved 45 RESERVED PCM_CLK* IO PCM clock signal 46 LED_WPAN# RESERVED Reserved 47 RESERVED PCM_DOUT* DO PCM data output 48 1.5V NC
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 19 / 41 1. The typical supply voltage is 3.3V. 2. Keep all NC, reserved and unused pins unconnected. 3. “*” means the digital audio (PCM) function is only supported on Telematics version. 3.2.2. Pin Assignment The following figure shows the pin assignment of EC21 Mini PCIe module. The top side contains EC21 module and antenna connectors. Figure 2: Pin Assignment 49 RESERVED PCM_DIN* DI PCM data input 50 GND GND Mini card ground 51 RESERVED PCM_SYNC* IO PCM frame synchronization 52 3.3Vaux VCC_3V3 PI 3.3V DC supply NOTES
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 20 / 41 3.3. Power Supply The following table shows pin definition of VCC_3V3 pins and ground pins. Table 5: Definition of VCC_3V3 and GND Pins The typical supply voltage of EC21 Mini PCIe is 3.3V. In the 2G networks, the input peak current may reach to 2.7A during the transmitting time, therefore the power supply must be able to provide enough current, and a bypass capacitor of no less than 470µF with low ESR should be used to prevent the voltage from dropping. The following figure shows a reference design of power supply. The precision of resistor R2 and R3 is 1%, and the capacitor C3 needs a low ESR. Figure 3: Reference Design of Power Supply Pin No. Pin Name I/O Power Domain Description 2, 39, 41, 52 VCC_3V3 PI 3.0~3.6V 3.3V DC supply 4, 9, 15, 18, 21, 26, 27, 29, 34, 35, 37, 40, 43, 50 GND Mini card ground
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 21 / 41 3.4. USIM Card Interface The following table shows the pin definition of USIM card interface. Table 6: USIM Pin Definition EC21 Mini PCIe supports 1.8V and 3.0V USIM cards. The following figure shows the reference design of the 6-pin USIM card connector. Figure 4: Reference Circuit of USIM Card Interface with a 6-Pin USIM Card Connector In order to enhance the reliability and availability of the USIM card in your application, please follow the criteria below in USIM circuit design:  Keep layout of USIM card as close to the module as possible. Assure the trace length as less than 200mm as possible.  Keep USIM card signal away from RF and power supply traces.  Keep the trace width of ground and USIM_VDD no less than 0.5mm to maintain the same electric potential. The decouple capacitor of USIM_VDD should be less than 1uF and must near to USIM card connector. Pin No. Pin Name I/O Power Domain Description 8 USIM_VDD PO 1.8V/3.0V Power source for the USIM card 10 USIM_DATA IO 1.8V/3.0V USIM data signal 12 USIM_CLK DO 1.8V/3.0V USIM clock signal 14 USIM_RST DO 1.8V/3.0V USIM reset signal
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 22 / 41  To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and shield them with surrounding ground.  In order to offer good ESD protection, it is recommended to add a TVS whose parasitic capacitance should not be more than 50pF. The 22 ohm resistors should be added in series between the module and USIM card so as to suppress EMI spurious transmission and enhance ESD protection. The 33pF capacitors are used for filtering interference of GSM900. Please note that the USIM peripheral circuit should be close to the USIM card connector.  The pull-up resistor on USIM_DATA line can improve anti-jamming capability when long layout trace and sensitive occasion are applied, and should be placed close to the USIM card connector. 3.5. USB Interface The following table shows the pin definition of USB interface. Table 7: Pin Definition of USB Interface EC21 Mini PCIe is compliant with USB 2.0 specification. It can only be used as a slave device. Meanwhile, it supports high speed (480Mbps) and full speed (12Mbps) mode. The USB interface is used for AT command communication, data transmission, GNSS NMEA output, software debugging, firmware upgrade and voice over USB*. The following figure shows the reference circuit of USB interface. Figure 5: Reference Circuit of USB Interface Pin No. Pin Name I/O Description Comment 36 USB_DM IO USB differential data (-) Require differential impedance of 90Ω 38 USB_DP IO USB differential data (+) Require differential impedance of 90Ω
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 23 / 41 In order to ensure the integrity of USB data line signal, components R1, R2, R3 and R4 must be placed close to the module, and also these resistors should be placed close to each other. The extra stubs of trace must be as short as possible. In order to ensure the USB interface design corresponding with the USB 2.0 specification, please comply with the following principles:  It is important to route the USB signal traces as differential pairs with total grounding. The impedance of USB differential trace is 90 ohm.  Do not route signal traces under crystals, oscillators, magnetic devices and RF signal traces. It is important to route the USB differential traces in inner-layer with ground shielding on not only upper and lower layers but also right and left sides.  If USB connector is used, please keep the ESD protection components to the USB connector as close as possible. Pay attention to the influence of junction capacitance of ESD protection components on USB data lines. Typically, the capacitance value should be less than 2pF.  Keep the ESD components as close as possible to the connector.  Keep traces of USB data test points short to avoid noise coupled on USB data lines. If possible, reserve a 0R resistor on these two lines. 1. There are three preconditions when enabling EC21 Mini PCIe to enter into the sleep mode: a) Execute AT+QSCLK=1 command to enable the sleep mode. Please refer to document [2] for details. b) DTR pin should be kept in high level (pull-up internally). c) USB interface on Mini PCIe must be connected with the USB interface of the host and please guarantee the USB of the host is in suspended state. 2. “*” means under development. 3.6. UART Interface The following table shows the pin definition of the UART interface. Table 8: Pin Definition of the UART Interface Pin No. EC21 Mini PCIe Pin Name I/O Power Domain Description 11 UART_RX DI 3.3V UART receive data 13 UART_TX DO 3.3V UART transmit data NOTES
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 24 / 41 The UART interface supports 9600, 19200, 38400, 57600, 115200 and 230400bps baud rate. The default is 115200bps. This interface can be used for AT command communication. AT+IPR command can be used to set the baud rate of the UART, and AT+IFC command can be used to set the hardware flow control (hardware flow control is disabled by default). Please refer to document [2] for details. 3.7. PCM and I2C Interfaces The following table shows the pin definition of PCM and 12C interfaces that can be applied in audio codec design. Table 9: Pin Definition of PCM and I2C Interfaces EC21 Mini PCIe provides one PCM digital interface, which supports 8-bit A-law* and μ-law*, and also supports 16-bit linear data formats and the following modes:  Primary mode (short frame synchronization, works as either master or slave)  Auxiliary mode (long frame synchronization, works as master only) 23 UART_CTS DI 3.3V UART clear to send 25 UART_RTS DO 3.3V UART request to send Pin No. Pin Name I/O Power Domain Description 45 PCM_CLK IO 1.8V PCM clock signal 47 PCM_DOUT DO 1.8V PCM data output 49 PCM_DIN DI 1.8V PCM data input 51 PCM_SYNC IO 1.8V PCM frame synchronization 30 I2C_SCL DO 1.8V I2C serial clock, require external pull-up to 1.8V. 32 I2C_SDA IO 1.8V I2C serial data, require external pull-up to 1.8V. NOTE
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 25 / 41 “*” means under development. In primary mode, the data is sampled on the falling edge of the PCM_CLK and transmitted on the rising edge. The PCM_SYNC falling edge represents the MSB. In this mode, PCM_CLK supports 128kHz, 256kHz, 512kHz, 1024kHz and 2048kHz. The following figure shows timing relationship in primary mode with 8kHz PCM_SYNC and 2048kHz PCM_CLK. Figure 6: Timing in Primary Mode In auxiliary mode, the data is sampled on the falling edge of the PCM_CLK and transmitted on the rising edge; while the PCM_SYNC rising edge represents the MSB. In this mode, PCM interface operates with a 128kHz PCM_CLK and an 8kHz, 50% duty cycle PCM_SYNC only. The following figure shows the timing relationship in auxiliary mode with 8kHz PCM_SYNC and 128kHz PCM_CLK. PCM_CLKPCM_SYNCPCM_DOUTMSB LSBPCM_IN125usMSB12 1615LSB Figure 7: Timing in Auxiliary Mode NOTE
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 26 / 41 Clock and mode can be configured by AT command, and the default configuration is master mode using short frame synchronization data format with 2048kHz PCM_CLK and 8kHz PCM_SYNC. In addition, EC21 Mini PCIe’s firmware has integrated the configuration on some PCM codec’s application with I2C interface. Please refer to document [2] for details about AT+QDAI command. The following figure shows a reference design of PCM interface with external codec IC. Figure 8: Reference Circuit of PCM Application with Audio Codec 3.8. Control Signals The following table shows the pin definition of control signals. Table 10: Pin Definition of Control Signal Pin No. Pin Name I/O Power Domain Description 17 RI DO 3.3V Output signal can be used to wake up the host. 31 DTR DI 3.3V Sleep mode control. 20 W_DISABLE# DI 3.3V Disable wireless communications, pull-up by default, active low. 22 PERST# DI 3.3V Functional reset to the card, active low.42 LED_WWAN# OC Active-low. LED signal for indicating the state of the module. 1 WAKE# OC Output signal can be used to wake up the host.
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 27 / 41 3.8.1. RI Signal The RI signal can be used to wake up the host. When URC returns, there will be the following behavior on the RI pin after executing AT+QCFG=“risignaltype”,“physical” command. URC return120 msHighLow Figure 9: RI Behavior 3.8.2. DTR Signal The DTR signal supports sleep control function. Driving it to low level will wake up the module. 3.8.3. W_DISABLE# Signal EC21 Mini PCIe provides W_DISABLE# signal to disable wireless communications through hardware operation. The following table shows the radio operational states of the module. Please refer to document [2] for related AT commands. Table 11: Radio Operational States 3.8.4. PERST# Signal The PERST# signal can be used to force a hardware reset on the card. You can reset the module by driving the PERST# to a low level voltage within the time frame of 150~460ms and then releasing it. The reset scenario is illustrated in the following figure. W_DISABLE# AT Commands Radio Operation High Level AT+CFUN=1 Enabled High Level AT+CFUN=0 AT+CFUN=4 Disabled Low Level AT+CFUN=0 AT+CFUN=1 AT+CFUN=4 Disabled
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 28 / 41 Figure 10: Timing of Resetting Module 3.8.5. LED_WWAN# Signal The LED_WWAN# signal of EC21 Mini PCIe is used to indicate the network status of the module, which can absorb the current up to 40mA. According to the following circuit, in order to reduce the current of the LED, a resistor must be placed in series with the LED. The LED is emitting light when the LED_WWAN# output signal is active low. Figure 11: LED_WWAN# Signal Reference Circuit Diagram The following table shows the network status indications of the LED_WWAN# signal. Table 12: Indications of Network Status LED_WWAN# Description Low Level (Light on) Registered on network High-impedance (Light off)  No network coverage or not registered  W_DISABLE# signal is at low level. (Disable the RF)  AT+CFUN=0, AT+CFUN=4
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 29 / 41 3.8.6. WAKE# Signal The WAKE# signal is an open collector signal which is similar to RI signal, but a host pull-up resistor and AT+QCFG=“risignaltype”,“physical” command are required. When URC returns, there will be 120ms low level pulse output as below. Figure 12: WAKE# Behavior 3.9. Antenna Interfaces EC21 Mini PCIe antenna interfaces include a main antenna interface, a Rx-diversity antenna interface and a GNSS antenna interface. And Rx-diversity function is enabled by default. The following table shows the requirement on main antenna, Rx-diversity antenna and GNSS antenna. Table 13: Antenna Requirements Type Requirements GNSS Frequency range: 1561~1615MHz Polarization: RHCP or linear VSWR: <2 (Typ.) Passive antenna gain: >0dBi GSM/WCDMA/LTE VSWR: ≤2 Gain (dBi): 1 Max Input Power (W): 50 Input Impedance (ohm): 50 Polarization Type: Vertical Cable Insertion Loss: <1dB (GSM900, WCDMA B5/B8, LTE B5/B8/B12/B13/B20/B28) Cable Insertion Loss: <1.5dB (GSM1800, WCDMA B1/B2, LTE B1/B2/B3/B4) Cable insertion loss <2dB (LTE B7)
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 30 / 41 The following figure shows the overall sizes of RF connector. Figure 13: Dimensions of the RF Connector (Unit: mm) U.FL-LP serial connectors listed in the following figure can be used to match the RF connector. Figure 14: Mechanicals of UF.L-LP Connectors
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 31 / 41 4 Electrical and Radio Characteristics 4.1. General Description This chapter mainly describes the following electrical and radio characteristics of EC21 Mini PCIe:  Power supply requirements  I/O requirements  Current consumption  RF characteristics  GNSS receiver  ESD characteristics 4.2. Power Supply Requirements The input voltage of EC21 Mini PCIe is 3.3V±9%, as specified by PCI Express Mini CEM Specifications 1.2. The following table shows the power supply requirements of EC21 Mini PCIe. Table 14: Power Supply Requirements Parameter Description Min. Typ. Max. Unit VCC_3V3 Power Supply 3.0 3.3 3.6 V
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 32 / 41 4.3. I/O Requirements The following table shows the I/O requirements of EC21 Mini PCIe. Table 15: I/O Requirements 1. The PCM and I2C interfaces belong to 1.8V power domain and other I/O interfaces belong to VCC_3V3 power domain. 2. The maximum voltage value of VIL for PERST# signal and W_DISABLE# signal is 0.5V. 4.4. RF Characteristics The following tables show conducted RF output power and receiving sensitivity of EC21 Mini PCIe module. Table 16: EC21 Mini PCIe Conducted RF Output Power Parameter Description Min. Max. Unit VIH Input High Voltage 0.7 × VCC_3V3 VCC_3V3+0.3 V VIL Input Low Voltage -0.3 0.3 × VCC_3V3 V VOH Output High Voltage VCC_3V3-0.5 VCC_3V3 V VOL Output Low Voltage 0 0.4 V Frequency Max. Min. GSM850/GSM900 33dBm±2dB 5dBm±5dB DCS1800/PCS1900 30dBm±2dB 0dBm±5dB GSM850/GSM900 (8-PSK) 27dBm±3dB 5dBm±5dB DCS1800/PCS1900 (8-PSK) 26dBm±3dB 0dBm±5dB WCDMA bands 24dBm+1/-3dB <-50dBm LTE-FDD bands 23dBm±2dB <-44dBm NOTES
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 33 / 41 Table 17: EC21-E Mini PCIe Conducted RF Receiving Sensitivity Frequency Primary Diversity SIMO 3GPP (SIMO) GSM -109.0dBm / / -102.0dBm DCS -109.0dBm / / -102.0dbm WCDMA B1 -110.5dBm / / -106.7dBm WCDMA B5 -110.5dBm / / -104.7dBm WCDMA B8 -110.5dBm / / -103.7dBm LTE-FDD B1 (10M) -98.0dBm -98.0dBm -101.5dBm -96.3dBm LTE-FDD B3 (10M) -96.5dBm -98.5dBm -101.5dBm -93.3dBm LTE-FDD B5 (10M) -98.0dBm -98.5dBm -101.0dBm -94.3dBm LTE-FDD B7 (10M) -97.0dBm -94.5dBm -99.5dBm -94.3dBm LTE-FDD B8 (10M) -97.0dBm -97.0dBm -101.0dBm -93.3dBm LTE-FDD B20 (10M) -97.5dBm -99.0dBm -102.5dBm -93.3dBm Table 18: EC21-A Mini PCIe Conducted RF Receiving Sensitivity frequency Primary Diversity SIMO 3GPP (SIMO) WCDMA B2 -110.0dBm / / -104.7dBm WCDMA B4 -110.0dBm / / -106.7dBm WCDMA B5 -110.5dBm / / -104.7dBm LTE-FDD B2 (10M) -98.0dBm -98.0dBm -101.0dBm -94.3dBm LTE-FDD B4 (10M) -97.5dBm -99.0dBm -101.0dBm -96.3dBm LTE-FDD B12 (10M) -96.5dBm -98.0dBm -101.0dBm -93.3dBm LTE-TDD bands 23dBm±2dB <-44dBm
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 34 / 41 Table 19: EC21-V Mini PCIe Conducted RF Receiving Sensitivity Frequency Primary Diversity SIMO 3GPP (SIMO) LTE-FDD B4 (10M) -97.5dBm -99.0dBm -101.0dBm -96.3dBm LTE-FDD B13 (10M) -95.0dBm -97.0dBm -100.0dBm -93.3dBm Table 20: EC21-AUT Mini PCIe Conducted RF Receiving Sensitivity Frequency Primary Diversity SIMO 3GPP (SIMO) WCDMA B1 -110.0dBm / / -106.7dBm WCDMA B5 -110.5dBm / / -104.7dBm LTE-FDD B1 (10M) -98.5dBm -98.0dBm -101.0dBm -96.3dBm LTE-FDD B3 (10M) -98.0dBm -96.0dBm -100.0dBm -93.3dBm LTE-FDD B5 (10M) -98.0dBm -99.0dBm -102.5dBm -94.3dBm LTE-FDD B7 (10M) -97.0dBm -95.0dBm -98.5dBm -94.3dBm LTE-FDD B28 (10M) -97.0dBm -99.0dBm -102.0dBm -94.8dBm Table 21: EC21-KL Mini PCIe Conducted RF Receiving Sensitivity Frequency Primary Diversity SIMO 3GPP (SIMO) LTE-FDD B1 (10M) -98.0dBm -99.5dBm -100.5dBm -96.3dBm LTE-FDD B3 (10M) -97.0dBm -97.5dBm -99.5dBm -93.3dBm LTE-FDD B5 (10M) -98.0dBm -99.5dBm -100.5dBm -94.3dBm LTE-FDD B7 (10M) -96.0dBm -96.0dBm -98.5dBm -94.3dBm LTE-FDD B8 (10M) -97.0dBm -99.0dBm -101.0dBm -93.3dBm
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 35 / 41 Table 22: EC21-J Mini PCIe Conducted RF Receiving Sensitivity 4.5. GNSS Receiver EC21 Mini PCIe integrates a GNSS receiver that supports Gen8C Lite of Qualcomm (GPS, GLONASS, BeiDou, Galileo and QZSS). Meanwhile, it supports Qualcomm gpsOneXTRA technology (one kind of A-GNSS). This technology will download XTRA file from the internet server to enhance the TTFF. XTRA file contains predicted GPS and GLONASS satellites coordinates and clock biases valid for up to 7 days. It is best if XTRA file is downloaded every 1-2 days. Additionally, EC21 Mini PCIe can support standard NMEA-0183 protocol and output NMEA messages with 1Hz via USB NMEA interface. EC21 Mini PCIe GNSS engine is switched off by default. You must switch on it by AT command. Please refer to document [3] for more details about GNSS engine technology and configurations. A passive antenna should be used for the GNSS engine. 4.6. ESD Characteristics The following table shows the ESD characteristics of EC21 Mini PCIe. Table 23: ESD Characteristics of EC21 Mini PCIe Frequency Primary Diversity SIMO 3GPP (SIMO) LTE-FDD B1 (10M) -97.5dBm -98.7dBm -100.2dBm -96.3dBm LTE-FDD B3 (10M) -96.5dBm -97.1dBm -100.5dBm -93.3dBm LTE-FDD B8 (10M) -98.4dBm -99.0dBm -101.2dBm -93.3dBm LTE-FDD B18 (10M) -99.5dBm -99.0dBm -101.7dBm -96.3dBm LTE-FDD B19 (10M) -99.2dBm -99.0dBm -101.4dBm -96.3dBm LTE-FDD B26 (10M) -99.5dBm -99.0dBm -101.5dBm -93.8dBm Part Contact Discharge Air Discharge Unit Power Supply and GND +/-5 +/-10 kV Antenna Interface +/-4 +/-8 kV
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 36 / 41 4.7. Current Consumption The following tables describe the current consumption of EC21 Mini PCIe series module. Table 24: Current Consumption of EC21-A Mini PCIe Parameter Description Conditions Typ. Unit IVBAT Sleep state AT+CFUN=0 (USB disconnected) 3.5 mA WCDMA PF=64 (USB disconnected) 5.0 mA WCDMA PF=128 (USB disconnected) 4.4 mA LTE-FDD PF=64 (USB disconnected) 5.3 mA LTE-FDD PF=128 (USB disconnected) 4.5 mA Idle state WCDMA PF=64 (USB disconnected) 32.0 mA WCDMA PF=64 (USB connected) 45.0 mA LTE-FDD PF=64 (USB disconnected) 32.0 mA LTE-FDD PF=64 (USB connected) 45.0 mA WCDMA data transfer (GNSS OFF) WCDMA B2 HSDPA @21.59dBm 582.0 mA WCDMA B2 HSUPA @22.17dBm 675.0 mA WCDMA B4 HSDPA @21.47dBm 575.0 mA WCDMA B4 HSUPA @21.73dBm 637.0 mA WCDMA B5 HSDPA @20.02dBm 686.0 mA WCDMA B5 HSUPA @20.18dBm 577.0 mA LTE data transfer (GNSS OFF) LTE-FDD B2 @22.93dBm 926.0 mA LTE-FDD B4 @22.72dBm 934.0 mA USB Interface +/-4 +/-8 kV USIM Interface +/-4 +/-8 kV Others +/-0.5 +/-1 kV
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 37 / 41 LTE-FDD B12 @23.26dBm 835.0 mA WCDMA voice call WCDMA B2 @22.88dBm 610.0 mA WCDMA B4 @23.21dBm 743.0 mA WCDMA B5 @23.13dBm 643.0 mA Table 25: Current Consumption of EC21-V Mini PCIe Parameter Description Conditions Typ. Unit IVBAT Sleep state AT+CFUN=0 (USB disconnected) 3.8 mA LTE-FDD PF=64 (USB disconnected) 5.3 mA LTE-FDD PF=128 (USB disconnected) 4.9 mA Idle state LTE-FDD PF=64 (USB disconnected) 30.0 mA LTE-FDD PF=64 (USB connected) 42.0 mA LTE data transfer (GNSS OFF) LTE-FDD B4 @23.59dBm 997.0 mA LTE-FDD B13 @24.05dBm 724.0 mA Table 26: Current Consumption of EC21-KL Mini PCIe Parameter Description Conditions Typ. Unit IVBAT Sleep state AT+CFUN=0 (USB disconnected) 3.5 mA LTE-FDD PF=64 (USB disconnected) 5.6 mA LTE-FDD PF=128 (USB disconnected) 4.7 mA Idle state LTE-FDD PF=64 (USB disconnected) 35.0 mA LTE-FDD PF=64 (USB connected) 49.0 mA LTE data transfer (GNSS OFF) LTE-FDD B1 @22.78dBm 972.0 mA LTE-FDD B3 @23.03dBm 974.0 mA LTE-FDD B5 @23.03dBm 764.0 mA LTE-FDD B7 @22.89dBm 959.0 mA
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 38 / 41 LTE-FDD B8 @22.86dBm 839.0 mA Table 27: GNSS Current Consumption of EC21 Mini PCIe Series Module Parameter Description Conditions Typ. Unit IVBAT (GNSS) Searching (AT+CFUN=0)Cold start @Passive Antenna 75.0 mA Lost state @Passive Antenna 74.0 mA Tracking (AT+CFUN=0)Instrument environment 44.0 mA Open Sky @Passive Antenna 53.0 mA Open Sky @Active Antenna 58.0 mA
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 39 / 41 5 Dimensions and Packaging 5.1. General Description This chapter mainly describes mechanical dimensions as well as packaging specification of EC21 Mini PCIe module. 5.2. Mechanical Dimensions of EC21 Mini PCIe 10.35±0.1034.30±0.204.00±0.1048.05±0.206.35±0.103x3.00 5.98±0.106.38±0.105.45±0.108.25±0.10 24.20±0.2030.00±0.20Pin1 Pin51 1.007.26±0.109.90±0.101.404.90±0.200.612.35±0.1050.95±0.20Top View Side View2xΦ2.60 Figure 15: Mechanical Dimensions of EC21 Mini PCIe (Unit: mm)
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 40 / 41 5.3. Standard Dimensions of Mini PCI Express The following figure shows the standard dimensions of Mini PCI Express. Please refer to document [1] for detailed A and B. Figure 16: Standard Dimensions of Mini PCI Express (Unit: mm)
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 41 / 41 EC21 Mini PCIe adopts a standard Mini PCI Express connector which compiles with the directives and standards listed in the document [1]. The following figure takes the Molex 679100002 as an example. Figure 17: Dimensions of the Mini PCI Express Connector (the Molex 679100002, Unit: mm) 5.4. Packaging Specification The EC21 Mini PCIe is packaged in tray. Each tray contains 10pcs of modules. The smallest package of EC21 Mini PCIe contains 100pcs.
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 42 / 41 6 Appendix References Table 28: Related Documents Table 29: Terms and Abbreviations SN Document Name Remark [1] PCI Express Mini Card Electromechanical Specification Revision 1.2 Mini PCI Express Specification [2] Quectel_EC25&EC21_AT_Commands_Manual EC25 and EC21 AT Commands Manual[3] Quectel_EC25&EC21_GNSS_AT_Commands_ Manual EC25 and EC21 GNSS AT Commands Manual Abbreviation Description AMR Adaptive Multi-rate bps Bits Per Second CS Coding Scheme DC-HSPA+ Dual-carrier High Speed Packet Access DFOTA Delta Firmware Upgrade Over The Air DL Down Link EFR Enhanced Full Rate ESD Electrostatic Discharge FDD Frequency Division Duplexing FR Full Rate GLONASS GLObalnaya Navigatsionnaya Sputnikovaya Sistema, the Russian Global Navigation Satellite System GMSK Gaussian Minimum Shift Keying GNSS Global Navigation Satellite System
LTE Module Series EC21 Mini PCIe Hardware Design EC21_Mini_PCIe_Hardware_Design Confidential / Released 43 / 41 GPS Global Positioning System GSM Global System for Mobile Communications HR Half Rate HSPA High Speed Packet Access HSUPA High Speed Uplink Packet Access kbps Kilo Bits Per Second LED Light Emitting Diode LTE Long-Term Evolution Mbps Million Bits Per Second ME Mobile Equipment (Module) MIMO Multiple-Input Multiple-Output MMS Multimedia Messaging Service MO Mobile Originated MT Mobile Terminated PCM Pulse Code Modulation PDU Protocol Data Unit PPP Point-to-Point Protocol RF Radio Frequency Rx Receive USIM Universal Subscriber Identification Module SMS Short Message Service UART Universal Asynchronous Receiver & Transmitter UL Up Link URC Unsolicited Result Code WCDMA Wideband Code Division Multiple Access

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