Quectel Wireless Solutions 201202M35 GSM/GPRS Module User Manual M10 Hardware Design

Quectel Wireless Solutions Company Limited GSM/GPRS Module M10 Hardware Design

Users Manual

M35 Hardware Design M35_HD_V1.0 - 1 - M35 Quectel Cellular Engine Hardware Design M35_HD_V1.0
M35 Hardware Design M35_HD_V1.0 - 2 - General Notes Quectel offers this information as a service to its customers, to support application and engineering efforts that use the products designed by Quectel. The information provided is based upon requirements specifically provided for customers of Quectel. Quectel has not undertaken any independent search for additional information, relevant to any information that may be in the customer’s possession. Furthermore, system validation of this product designed by Quectel within a larger electronic system remains the responsibility of the customer or the customer’s system integrator. All specifications supplied herein are subject to change. Copyright This document contains proprietary technical information of Quectel Co., Ltd. Copying this document, distribution to others, and communication of the contents thereof, are forbidden without permission. Offenders are liable to the payment of damages. All rights are reserved in the event of a patent grant or registration of a utility model or design. All specifications supplied herein are subject to change without notice at any time. Copyright © Shanghai Quectel Wireless Solutions Ltd. 2012 Document Title M35 Hardware Design Revision 1.0 Date 2012-02-06 Status Released Document Control ID M35_HD_V1.0 QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 3 - Contents Contents ............................................................................................................................................ 3 Table Index ....................................................................................................................................... 5 Figure Index ...................................................................................................................................... 6 0. Revision history ............................................................................................................................ 8 1. Introduction ................................................................................................................................... 9 1.1. Related documents ............................................................................................................. 9 1.2. Terms and abbreviations .................................................................................................. 10 1.3. Directives and standards .................................................................................................. 12 1.3.1. FCC Statement ...................................................................................................... 12 1.3.2. FCC/IC Radiation exposure statement .................................................................. 12 1.3.3. Industry Canada licence ........................................................................................ 12 1.4. Safety cautions ................................................................................................................. 13 2. Product concept ........................................................................................................................... 15 2.1. Key features ..................................................................................................................... 15 2.2. Functional diagram .......................................................................................................... 17 2.3. Evaluation board .............................................................................................................. 18 3. Application interface ................................................................................................................... 19 3.1. Pin .................................................................................................................................... 20 3.1.1. Pin assignment ...................................................................................................... 20 3.1.2. Pin description ....................................................................................................... 21 3.2. Operating modes .............................................................................................................. 26 3.3. Power supply .................................................................................................................... 27 3.3.1. Feature of GSM power .......................................................................................... 27 3.3.2. Minimize supply voltage drop............................................................................... 27 3.3.3. Reference power design for the module ................................................................ 28 3.3.4. Monitor power supply ........................................................................................... 29 3.4. Power on and down scenarios .......................................................................................... 29 3.4.1. Power on ............................................................................................................... 29 3.4.2. Power down ........................................................................................................... 31 3.4.3. Restart ................................................................................................................... 35 3.5. Power saving .................................................................................................................... 36 3.5.1. Minimum functionality mode................................................................................ 36 3.5.2. Sleep mode ............................................................................................................ 36 3.5.3. Wake up the module from SLEEP mode .............................................................. 37 3.6. Summary of state transitions ............................................................................................ 37 3.7. RTC backup ..................................................................................................................... 37 3.8. Serial interfaces ................................................................................................................ 39 3.8.1. UART Port ............................................................................................................ 40 3.8.2. Debug Port ............................................................................................................ 44 3.8.3. UART Application ................................................................................................ 44 3.9. Audio interfaces ............................................................................................................... 48 QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 4 - 3.9.1. Decrease TDD noise and other noise .................................................................... 49 3.9.2. Microphone interfaces design ............................................................................... 50 3.9.3. Receiver interface design ...................................................................................... 50 3.9.4. Earphone interface design ..................................................................................... 51 3.9.5. Loud speaker interface design ............................................................................... 51 3.9.6. Audio characteristics ............................................................................................. 52 3.10. SIM card interface .......................................................................................................... 52 3.10.1. SIM card application ........................................................................................... 52 3.10.2. 6 Pin SIM cassette ............................................................................................... 54 3.12. Behaviors of the RI ........................................................................................................ 55 3.13. Network status indication ............................................................................................... 57 3.14. Operating status indication ............................................................................................. 57 4. Antenna interface ........................................................................................................................ 59 4.1. RF reference design ......................................................................................................... 59 4.2. RF output power ............................................................................................................... 60 4.3. RF receiving sensitivity.................................................................................................... 60 4.4. Operating frequencies ...................................................................................................... 60 4.5. RF cable soldering ........................................................................................................... 60 5. Electrical, reliability and radio characteristics ............................................................................ 62 5.1. Absolute maximum ratings .............................................................................................. 62 5.2. Operating temperature ...................................................................................................... 62 5.3. Power supply ratings ........................................................................................................ 62 5.4. Current consumption ........................................................................................................ 63 5.5. Electro-static discharge .................................................................................................... 64 6. Mechanical dimensions ............................................................................................................... 65 6.1. Mechanical dimensions of module ................................................................................... 65 6.2. Footprint of recommendation ........................................................................................... 67 6.3. Top view of the module ................................................................................................... 68 6.4. Bottom view of the module .............................................................................................. 69 7. Storage and Manufacturing ......................................................................................................... 70 7.1. Storage ............................................................................................................................. 70 7.3. Packaging ......................................................................................................................... 72 Appendix A: GPRS coding schemes ............................................................................................... 73 Appendix B: GPRS multi-slot classes............................................................................................. 74 QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 5 - Table Index TABLE 1: RELATED DOCUMENTS .................................................................................................... 9 TABLE 2: TERMS AND ABBREVIATIONS ...................................................................................... 10 TABLE 3: MODULE KEY FEATURES ............................................................................................... 15 TABLE 4: CODING SCHEMES AND MAXIMUM NET DATA RATES OVER AIR INTERFACE 17 TABLE 5: M35 PIN ASSIGNMENT..................................................................................................... 20 TABLE 6: PIN DESCRIPTION ............................................................................................................. 21 TABLE 7: OVERVIEW OF OPERATING MODES ............................................................................ 26 TABLE 8: SUMMARY OF STATE TRANSITION ............................................................................. 37 TABLE 9: LOGIC LEVELS OF THE UART INTERFACE ................................................................. 40 TABLE 10: PIN DEFINITION OF THE UART INTERFACES .......................................................... 40 TABLE 11: PIN DEFINITION OF AUDIO INTERFACE ................................................................... 48 TABLE 12: AOUT2 OUTPUT CHARACTERISTICS ......................................................................... 49 TABLE 13: TYPICAL ELECTRET MICROPHONE CHARACTERISTICS ...................................... 52 TABLE 14: TYPICAL SPEAKER CHARACTERISTICS ................................................................... 52 TABLE 15: PIN DEFINITION OF THE SIM INTERFACE ................................................................ 53 TABLE 16: PIN DESCRIPTION OF AMPHENOL SIM CARD HOLDER......................................... 54 TABLE 17: BEHAVIORS OF THE RI.................................................................................................. 55 TABLE 18: WORKING STATE OF THE NETLIGHT ........................................................................ 57 TABLE 19: PIN DEFINITION OF THE STATUS ............................................................................... 57 TABLE 20: PIN DEFINITION OF THE ANTENNA INTERFACE .................................................... 59 TABLE 21: THE MODULE CONDUCTED RF OUTPUT POWER ................................................... 60 TABLE 22: THE MODULE CONDUCTED RF RECEIVING SENSITIVITY ................................... 60 TABLE 23: THE MODULE OPERATING FREQUENCIES ............................................................... 60 TABLE 24: ABSOLUTE MAXIMUM RATINGS ................................................................................ 62 TABLE 25: OPERATING TEMPERATURE ........................................................................................ 62 TABLE 26: THE MODULE POWER SUPPLY RATINGS ................................................................. 62 TABLE 27: THE MODULE CURRENT CONSUMPTION ................................................................. 63 TABLE 28: THE ESD ENDURANCE (TEMPERATURE:25℃,HUMIDITY:45 %) .......................... 64 TABLE 29: DESCRIPTION OF DIFFERENT CODING SCHEMES .................................................. 73 TABLE 30: GPRS MULTI-SLOT CLASSES ....................................................................................... 74 QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 6 - Figure Index FIGURE 1: MODULE FUNCTIONAL DIAGRAM ............................................................................. 18 FIGURE 2: PIN ASSIGNMENT ........................................................................................................... 20 FIGURE 3: RIPPLE IN SUPPLY VOLTAGE DURING TRANSMITTING BURST.......................... 27 FIGURE 4: REFERENCE CIRCUIT OF THE VBAT INPUT .............................................................. 28 FIGURE 5: REFERENCE CIRCUIT OF THE SOURCE POWER SUPPLY INPUT .......................... 28 FIGURE 6: TURN ON THE MODULE USING DRIVING CIRCUIT ................................................ 30 FIGURE 7: TURN ON THE MODULE USING KEYSTROKE........................................................... 30 FIGURE 8: TIMING OF TURNING ON SYSTEM .............................................................................. 31 FIGURE 9: TIMING OF TURNING OFF THE MODULE .................................................................. 32 FIGURE 10: REFERENCE CIRCUIT FOR EMERG_OFF BY USING DRIVING CIRCUIT ............ 34 FIGURE 11: REFERENCE CIRCUIT FOR EMERG_OFF BY USING BUTTON ............................. 34 FIGURE 12: TIMING OF RESTARTING SYSTEM ............................................................................ 35 FIGURE 13: TIMING OF RESTARTING SYSTEM AFTER EMERGENCY SHUTDOWN ............. 35 FIGURE 14: RTC SUPPLY FROM NON-CHARGEABLE BATTERY .............................................. 38 FIGURE 15: RTC SUPPLY FROM RECHARGEABLE BATTERY ................................................... 38 FIGURE 16: RTC SUPPLY FROM CAPACITOR ............................................................................... 38 FIGURE 17: SEIKO XH414H-IV01E CHARGE CHARACTERISTICS ............................................. 39 FIGURE 18: CONNECTION OF ALL FUNCTIONAL UART PORT ................................................. 42 FIGURE 19: CONNECTION OF THREE LINES UART PORT .......................................................... 42 FIGURE 20: CONNECTION OF UART PORT ASSOCIATED HARDWARE FLOW CONTROL .. 43 FIGURE 21: CONNECTION OF SOFTWARE UPGRADE ................................................................ 43 FIGURE 22: CONNECTION OF SOFTWARE DEBUG...................................................................... 44 FIGURE 23: 3.3V LEVEL MATCH CIRCUIT ..................................................................................... 45 FIGURE 24: 5V LEVEL MATCH CIRCUIT ........................................................................................ 46 FIGURE 25: RS232 LEVEL MATCH CIRCUIT .................................................................................. 47 FIGURE 26: MICROPHONE INTERFACE DESIGN OF AIN1&AIN2 .............................................. 50 FIGURE 27: RECEIVER INTERFACE DESIGN OF AOUT1 ............................................................. 50 FIGURE 28: EARPHONE INTERFACE DESIGN ............................................................................... 51 FIGURE 29: LOUD SPEAKER INTERFACE DESIGN ...................................................................... 51 FIGURE 30: REFERENCE CIRCUIT OF THE 6 PINS SIM CARD ................................................... 53 FIGURE 31: AMPHENOL C707 10M006 512 2 SIM CARD HOLDER ............................................. 54 FIGURE 32: RI BEHAVIOR OF VOICE CALLING AS A RECEIVER ............................................. 55 FIGURE 33: RI BEHAVIOR OF DATA CALLING AS A RECEIVER .............................................. 56 FIGURE 34: RI BEHAVIOR AS A CALLER ....................................................................................... 56 FIGURE 35: RI BEHAVIOR OF URC OR SMS RECEIVED .............................................................. 56 FIGURE 36: REFERENCE CIRCUIT OF THE NETLIGHT ............................................................... 57 FIGURE 37: REFERENCE CIRCUIT OF THE STATUS .................................................................... 58 FIGURE 38: REFERENCE CIRCUIT OF RF ....................................................................................... 59 FIGURE 39: RF SOLDERING SAMPLE ............................................................................................. 61 FIGURE 40: M35 TOP AND SIDE DIMENSIONS（UNIT: MM） ................................................... 65 FIGURE 41: M35 BOTTOM DIMENSIONS（UNIT: MM） ............................................................. 66 QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 7 - FIGURE 42: FOOTPRINT ONE OF RECOMMENDATION（UNIT: MM） .................................... 67 FIGURE 43: TOP VIEW OF THE MODULE ....................................................................................... 68 FIGURE 44: BOTTOM VIEW OF THE MODULE .............................................................................. 69 FIGURE 45: PASTE APPLICATION ................................................................................................... 71 FIGURE 46: RAMP-SOAK-SPIKE REFLOW PROFILE .................................................................... 72 FIGURE 47: MODULE TRAY .............................................................................................................. 72 FIGURE 48: RADIO BLOCK STRUCTURE OF CS-1, CS-2 AND CS-3 ........................................... 73 FIGURE 49: RADIO BLOCK STRUCTURE OF CS-4 ........................................................................ 73 QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 8 - 0. Revision history Revision Date Author Description of change 1.0 2011-12-29 Luka WU Initial QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 9 - 1. Introduction This document defines Module M35 and describes its hardware interface which are connected with the customer application and the air interface. This document can help customers quickly understand the interface specifications, electrical and mechanical details of M35. Associated with application notes and user guide, customers can use M35 to design and set up mobile applications easily. 1.1. Related documents Table 1: Related documents SN Document name Remark [1] M35_ATC AT commands set [2] ITU-T Draft new recommendation V.25ter Serial asynchronous automatic dialing and control [3] GSM 07.07 Digital cellular telecommunications (Phase 2+); AT command set for GSM Mobile Equipment (ME) [4] GSM 07.10 Support GSM 07.10 multiplexing protocol [5] GSM 07.05 Digital cellular telecommunications (Phase 2+); Use of Data Terminal Equipment – Data Circuit terminating Equipment (DTE – DCE) interface for Short Message Service (SMS) and Cell Broadcast Service (CBS) [6] GSM 11.14 Digital cellular telecommunications (Phase 2+); Specification of the SIM Application Toolkit for the Subscriber Identity module – Mobile Equipment (SIM – ME) interface [7] GSM 11.11 Digital cellular telecommunications (Phase 2+); Specification of the Subscriber Identity module – Mobile Equipment (SIM – ME) interface [8] GSM 03.38 Digital cellular telecommunications (Phase 2+); Alphabets and language-specific information [9] GSM 11.10 Digital cellular telecommunications (Phase 2); Mobile Station (MS) conformance specification; Part 1: Conformance specification [10] GSM_UART_AN UART port application notes [11] GSM_FW_Upgrade_Tool_ Lite_GS2_UDG GSM Firmware upgrade tool lite GS2 user guide [12] M35_EVB_UGD M35 EVB user guide QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 10 - 1.2. Terms and abbreviations Table 2: Terms and abbreviations Abbreviation Description ADC Analog-to-Digital Converter AMR Adaptive Multi-Rate ARP Antenna Reference Point ASIC Application Specific Integrated Circuit BER Bit Error Rate BOM Bill Of Material BTS Base Transceiver Station CHAP Challenge Handshake Authentication Protocol CS Coding Scheme CSD Circuit Switched Data CTS Clear To Send DAC Digital-to-Analog Converter DRX Discontinuous Reception DSP Digital Signal Processor DCE Data Communications Equipment (typically module) DTE Data Terminal Equipment (typically computer, external controller) DTR Data Terminal Ready DTX Discontinuous Transmission EFR Enhanced Full Rate EGSM Enhanced GSM EMC Electromagnetic Compatibility ESD Electrostatic Discharge ETS European Telecommunication Standard FCC Federal Communications Commission (U.S.) FDMA Frequency Division Multiple Access FR Full Rate GMSK Gaussian Minimum Shift Keying GPRS General Packet Radio Service GSM Global System for Mobile Communications HR Half Rate I/O Input/Output IC Integrated Circuit IMEI International Mobile Equipment Identity Imax Maximum Load Current Inorm Normal Current kbps Kilo Bits Per Second LED Light Emitting Diode QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 11 - Li-Ion Lithium-Ion Abbreviation Description MO Mobile Originated MS Mobile Station (GSM engine) MT Mobile Terminated PAP Password Authentication Protocol PBCCH Packet Switched Broadcast Control Channel PCB Printed Circuit Board PDU Protocol Data Unit PPP Point-to-Point Protocol RF Radio Frequency RMS Root Mean Square (value) RTC Real Time Clock RX Receive Direction SIM Subscriber Identification Module SMS Short Message Service TDMA Time Division Multiple Access TE Terminal Equipment TX Transmitting Direction UART Universal Asynchronous Receiver & Transmitter URC Unsolicited Result Code USSD Unstructured Supplementary Service Data VSWR Voltage Standing Wave Ratio 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 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 Phonebook abbreviations FD SIM Fix Dialing phonebook LD SIM Last Dialing phonebook (list of numbers most recently dialed) MC Mobile Equipment list of unanswered MT Calls (missed calls) ON SIM (or ME) Own Numbers (MSISDNs) list RC Mobile Equipment list of Received Calls QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 12 - SM SIM phonebook 1.3. Directives and standards The M35 module is designed to comply with the FCC statements. FCC ID is XMR201202M35. The Host system using M35, should have label indicated FCC ID: XMR201202M35. 1.3.1. FCC Statement 1. This device complies with Part 15 of the FCC rules. Operation is subject to the following conditions: a) This device may not cause harmful interference. b) This device must accept any interference received, including interference that may cause undesired operation. 2. Changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment. 1.3.2. FCC/IC Radiation exposure statement This equipment complies with FCC/IC radiation exposure limits set forth for an uncontrolled environment. This equipment should be installed and operated with minimum distance 20cm between the radiator and your body as well as kept minimum 20cm from radio antenna depending on the portable or Mobile status of this module usage. The manual of the host system, which uses M35, must include RF exposure warning statement to advice user should keep minimum 20cm from the radio antenna of M35 module depending on portable or Mobile status. 1.3.3. Industry Canada licence Under Industry Canada regulations, this radio transmitter may only operate using an antenna of a type and maximum (or lesser) gain approved for the transmitter by Industry Canada. To reduce potential radio interference to other users, the antenna type and its gain should be so chosen that the equivalent isotropically radiated power (e.i.r.p.) is not more than that necessary for successful. The host system using M35 should have label indicating “transmitter module IC: 10224-201202M35. This radio transmitter (identify the device by certification number, or module number if Category II) has been approved by Industry Canada to operate with the antenna type listed below with the QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 13 - maximum permissible gain and required antenna impedance for each antenna type indicated. Antenna types not included in this list, having a gain greater than the maximum gain indicated for that type, are strictly prohibited for use with this device. The following list of antenna is indicating the maximum permissible antenna gain. Type Maximum Gain Impedance External Antenna Monopole 2dBi 50Ω Vehicular antenna 2dBi 50Ω Internal Antenna Monopole 2dBi 50Ω PIFA 2dBi 50Ω FPC 2dBi 50Ω PCB 2dBi 50Ω 1.4. Safety cautions 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 M35 module. Manufacturers of the cellular terminal should send the following safety information to users and operating personnel and to 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. When in a hospital or other health care facility, observe the restrictions about the use of mobile. Switch the cellular terminal or mobile off. Medical equipment may be sensitive to not operate normally for RF energy interference. Switch off the cellular terminal or mobile before boarding an aircraft. Make sure it switched off. The operation of wireless appliances in an aircraft is forbidden to prevent interference with communication systems. Forget to think much of these instructions may lead to the flight safety or offend against local legal action, or both. Do not operate the cellular terminal or mobile in the presence of flammable gas or fume. Switch off the cellular terminal when you are near petrol station, fuel depot, chemical plant or where blasting operations are in progress. Operation of any electrical equipment in potentially explosive atmosphere can constitute a safety hazard. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 14 - Your cellular terminal or mobile receives and transmits radio frequency energy while switched on. RF interference can occur if it is used close to TV set, radio, computer or other electric equipment. Road safety comes first! Do not use a hand-held cellular terminal or mobile while driving a vehicle, unless it is securely mounted in a holder for hands-free operation. Before making a call with a hand-held terminal or mobile, park the vehicle. GSM cellular terminals or mobiles operate over radio frequency signal and cellular network and cannot be guaranteed to connect in all conditions, for example no mobile fee or an invalid SIM card. While you are in this condition and need emergent help, Please Remember using emergency call. In order to make or receive call, the cellular terminal or mobile must be switched on and in a service area with adequate cellular signal strength. Some networks do not allow for emergency call if certain network services or phone features are in use (e.g. lock functions, fixed dialing etc.). You may have to deactivate those features before you can make an emergency call. Also, some networks require that a valid SIM card be properly inserted in cellular terminal or mobile. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 15 - 2. Product concept M35 is a Quad-band GSM/GPRS engine that works at frequencies of GSM850MHz, GSM900MHz, DCS1800MHz and PCS1900MHz. The M35 features GPRS multi-slot class 12 and supports the GPRS coding schemes CS-1, CS-2, CS-3 and CS-4. For more details about GPRS multi-slot classes and coding schemes, please refer to Appendix A and Appendix B. With a tiny profile of 19.9mm × 23.6mm × 2.65mm, the module can meet the requirements of almost all M2M applications, including Tracking and Tracing, Industrial PDA, Wireless POS, Intelligent Measurement, Remote Controlling, etc. M35 is an SMD type module with LCC package, which can be embedded in customer applications. It provides abundant hardware interfaces between the module and customer’s host board. Designed with power saving technique, the current consumption of M35 module is as low as 0.9 mA in SLEEP mode when DRX is 5. M35 is integrated with Internet service protocols, which are TCP/IP, UDP, FTP and PPP. Extended AT commands have been developed for customer to use these Internet service protocols easily. The module fully complies to FCC statements and RoHS directive of the European Union. 2.1. Key features Table 3: Module key features Feature Implementation Power supply Single supply voltage 3.3V ~ 4.6V Typical supply voltage 4V Power saving Typical power consumption in SLEEP mode: 0.9 mA@ DRX=5 0.7 mA@ DRX=9 Frequency bands  Quad-band: GSM850, GSM900, DCS1800, PCS1900.  The module can search these frequency bands automatically  The frequency bands can be set by AT command.  Compliant with GSM Phase 2/2+ GSM class Small MS Transmitting power  Class 4 (2W) at GSM850 and GSM900  Class 1 (1W) at DCS1800 and PCS1900 GPRS connectivity  GPRS multi-slot class 12 (default)  GPRS multi-slot class 1~12 (configurable)  GPRS mobile station class B QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 16 - Temperature range  Normal operation: -35°C ~ +80°C  Restricted operation: -40°C ~ -35°C and +80°C ~ +85°C 1)  Storage temperature: -45°C ~ +90°C DATA GPRS: CSD:  GPRS data downlink transfer: max. 85.6 kbps  GPRS data uplink transfer: max. 85.6 kbps  Coding schemes: CS-1, CS-2, CS-3 and CS-4  Support the protocols PAP (Password Authentication Protocol) usually used for PPP connections  Internet service protocols TCP/UDP/FTP/HTTP  Support Packet Switched Broadcast Control Channel (PBCCH)  CSD transmission rates: 2.4, 4.8, 9.6, 14.4 kbps non-transparent  Support Unstructured Supplementary Services Data (USSD) SMS  Text and PDU mode  SMS storage: SIM card FAX Group 3 Class 1 and Class 2 SIM interface Support SIM card: 1.8V, 3V Audio features Speech codec modes:  Half Rate (ETS 06.20)  Full Rate (ETS 06.10)  Enhanced Full Rate (ETS 06.50 / 06.60 / 06.80)  Adaptive Multi-Rate (AMR)  Echo Cancellation  Echo Suppression  Noise Reduction  Embedded one amplifier of class AB with maximum driving power up to 800mW UART interface UART Port:  Seven lines on UART port interface  Use for AT command, GPRS data and CSD data  Multiplexing function  Support autobauding from 4800 bps to 115200 bps Debug Port:  Two lines on debug UART port interface DBG_TXD and DBG_RXD  Debug Port only used for software debugging Phonebook management Support phonebook types: SM, ME, FD, ON, MT SIM Application Toolkit Support SAT class 3, GSM 11.14 Release 99 Real time clock Implemented Physical characteristics Size: 19.9±0.15 × 23.6±0.15 × 2.65±0.2mm Weight: 3g Firmware upgrade Firmware upgrade via UART Port Antenna interface Connected via 50 Ohm antenna pad QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 17 - Table 4: Coding schemes and maximum net data rates over air interface Coding scheme 1 Timeslot 2 Timeslot 4 Timeslot CS-1: 9.05kbps 18.1kbps 36.2kbps CS-2: 13.4kbps 26.8kbps 53.6kbps CS-3: 15.6kbps 31.2kbps 62.4kbps CS-4: 21.4kbps 42.8kbps 85.6kbps 2.2. Functional diagram The following figure shows a block diagram of the M35 module and illustrates the major functional parts:  Power management  Baseband  The GSM radio frequency part  The Peripheral interface —SIM interface —Audio interface —UART interface —Power supply —RF interface —Turn on/off interface —RTC interface QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 18 - MT6252D32.768KControl26MPower supplyUARTSIMVDD_EXTAUDIOPWRKEYEMERG_OFFVRTCRF_ANTENNAPA TQM6M4068Application Interface (42-SMD Pads) Figure 1: Module functional diagram 2.3. Evaluation board In order to help customer to develop applications with M35, Quectel supplies an evaluation board (EVB), RS-232 to USB cable, power adapter, earphone, antenna and other peripherals to control or test the module. For details, please refer to the document [12]. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 19 - 3. Application interface The module is equipped with 42 pin SMT pad and it adopts LCC package. Detailed descriptions on Sub-interfaces included in these pads are given in the following chapters:  Power supply  Turn on/off  Power saving  RTC  UART interfaces  Audio interfaces  SIM interface QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 20 - 3.1. Pin 3.1.1. Pin assignment Figure 2: Pin assignment Table 5: M35 pin assignment PIN NO. PIN NAME I/O PIN NO. PIN NAME I/O 1 AGND 2 MIC2P I 3 MIC2N I 4 MIC1P I 5 MIC1N I 6 SPK1N O 7 SPK1P O 8 LOUDSPKN O 9 LOUDSPKP O 10 PWRKEY I 11 EMERG_OFF I 12 STATUS O QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 21 - 13 NETLIGHT O 14 DBG_RXD I 15 DBG_TXD O 16 RESERVED 17 RESERVED 18 RESERVED 19 VDD_EXT O 20 DTR I 21 RXD I 22 TXD O 23 CTS O 24 RTS I 25 DCD O 26 RI O 27 SIM_VDD O 28 SIM_RST O 29 SIM_DATA I/O 30 SIM_CLK O 31 SIM_GND 32 VRTC I/O 33 VBAT I 34 VBAT I 35 GND 36 GND 37 GND 38 GND 39 RF_ANT I/O 40 GND 41 RESERVED 42 RESERVED 3.1.2. Pin description Table 6: Pin description Power supply PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT VBAT 33, 34 I Main power supply of module: VBAT=3.3V~4.6V Vmax= 4.6V Vmin=3.3V Vnorm=4.0V Make sure that supply sufficient current in a transmitting burst which typically rises to 1.6A. VRTC 32 I/O Power supply for RTC when VBAT is not supplied for the system. Charging for backup battery or golden capacitor when the VBAT is supplied. VImax=VBAT VImin=2.6V VInorm=2.8V VOmax=2.85V VOmin=2.6V VOnorm=2.8V Iout(max)= 730uA Iin=2.6~5 uA If unused, keep this pin open. VDD_EXT 19 O Supply 2.8V voltage for external circuit. Vmax=2.9V Vmin=2.7V Vnorm=2.8V Imax=20mA 1. If unused, keep this pin open. 2. Recommended to add a 2.2~4.7uF QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 22 - bypass capacitor, when using this pin for power supply. GND 35, 36, 37, 38, 40 Ground Turn on/off PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT PWRKEY 10 I Power on/off key. PWRKEY should be pulled down for a moment to turn on or turn off the system. VILmax= 0.1*VBAT VIHmin= 0.6*VBAT VImax=VBAT Pulled up to VBAT internally. Emergency shutdown PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT EMERG_ OFF 11 I Emergency off. Pulled down for at least 20ms, which will turn off the module in case of emergency. Use it only when normal shutdown through PWRKEY or AT command cannot perform well. VILmax=0.4V VIHmin=2.2V Vopenmax=2.8V Open drain/collector driver required in cellular device application. If unused, keep this pin open. Module indicator PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT STATUS 12 O Indicate module operating status. High level indicates module is power-on and low level indicates power-down. VOHmin= 0.85*VDD_EXT VOLmax= 0.15*VDD_EXT If unused, keep this pin open. Audio interface PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT MIC1P MIC1N 4， 5 I Channel one of positive and negative If unused, keep these pins open. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 23 - voice-band input MIC2P MIC2N 2， 3 I Channel two of positive and negative voice-band input SPK1N SPK1P 6, 7 O Channel one of positive and negative voice-band output If unused, keep these pins open. AGND 1 Cooperate with LOUDSPKP If unused, keep this pin open. LOUDSPKN LOUDSPKP 8，9 O Channel two of positive and negative voice-band output 1. If unused, keep these pins open. 2. Embedded amplifier of class AB internally. 3. Support both Voice and ring. Net status indicator PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT NETLIGHT 13 O Network status indication VOHmin= 0.85*VDD_EXT VOLmax= 0.15*VDD_EXT If unused, keep this pin open. Main UART port PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT DTR 20 I Data terminal ready VILmin=-0.3V VILmax= 0.25*VDD_EXT VIHmin= 0.75*VDD_EXT VIHmax= VDD_EXT+0.3V VOHmin= 0.85*VDD_EXT VOLmax= 0.15*VDD_EXT If only use TXD, RXD and GND to communicate, recommended keeping other pins open, except RTS. Pull down RTS. RXD 21 I Receiving data TXD 22 O Transmitting data CTS 23 O Clear to send RTS 24 I Request to send DCD 25 O Data carrier detection RI 26 O Ring indicator Debug UART port PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 24 - DBG_RXD 14 I UART interface for debugging only. VILmin=-0.3V VILmax= 0.25*VDD_EXT VIHmin= 0.75*VDD_EXT VIHmax= VDD_EXT+0.3V VOHmin= 0.85*VDD_EXT VOLmax= 0.15*VDD_EXT If unused, keep these pins open. DBG_TXD 15 O SIM interface PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT SIM_ VDD 27 O Power supply for SIM card The voltage can be selected by software automatically. Either 1.8V or 3V. 1. All signals of SIM interface should be protected against ESD with a TVS diode array. 2. Maximum trace length is 200mm from the module pad to SIM card holder. SIM_RST 28 O SIM reset 3V： VOLmax=0.36V VOHmin= 0.9*SIM_VDD 1.8V: VOLmax= 0.2*SIM_VDD VOHmin= 0.9*SIM_VDD SIM_ DATA 29 I/O SIM data 3V： VOLmax=0.4V VOHmin= SIM_VDD-0.4V 1.8V: VOLmax= 0.15*SIM_VDD VOHmin= SIM1_VDD-0.4V SIM_CLK 30 O SIM clock 3V： VOLmax=0.4V VOHmin= 0.9*SIM_VDD 1.8V: VOLmax= 0.12*SIM_VDD QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 25 - VOHmin= 0.9*SIM_VDD SIM_GND 31 SIM ground RF interface PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT RF_ANT 39 I/O RF antenna pad Impedance of 50Ω QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 26 - 3.2. Operating modes The table below briefly summarizes the various operating modes in the following chapters. Table 7: Overview of operating modes Mode Function Normal operation GSM/GPRS SLEEP The module will automatically go into SLEEP mode if DTR is set to high level and there is no interrupt (such as GPIO interrupt or data on UART port). In this case, the current consumption of module will reduce to the minimal level. During SLEEP mode, the module can still receive paging message and SMS from the system normally. GSM IDLE Software is active. The module has registered to the GSM network, and the module is ready to send and receive GSM data. GSM TALK GSM connection is ongoing. In this mode, the power consumption is decided by the configuration of Power Control Level (PCL), dynamic DTX control and the working RF band. GPRS IDLE The module is not registered to GPRS network. The module is not reachable through GPRS channel. GPRS STANDBY The module is registered to GPRS network, but no GPRS PDP context is active. The SGSN knows the Routing Area where the module is located at. GPRS READY The PDP context is active, but no data transfer is going on. The module is ready to receive or send GPRS data. The SGSN knows the cell where the module is located at. GPRS DATA There is GPRS data in transfer. In this mode, power consumption is decided by the PCL, working RF band and GPRS multi-slot configuration. POWER DOWN Normal shutdown by sending the “AT+QPOWD=1” command, using the PWRKEY or the EMERG_OFF1) pin. The power management ASIC disconnects the power supply from the base band part of the module, and only the power supply for the RTC is remained. Software is not active. The UART interfaces are not accessible. Operating voltage (connected to VBAT) remains applied. Minimum functionality mode (without removing power supply) “AT+CFUN” command can set the module to a minimum functionality mode without removing the power supply. In this case, the RF part of the module will not work or the SIM card will not be accessible, or both RF part and SIM card will be disabled, but the UART port is still accessible. The power consumption in this case is very low. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 27 - 1) Use the EMERG_OFF pin only while failing to turn off the module by the command “AT+QPOWD=1” and the PWRKEY pin. Please refer to Section 3.4.2.2. 3.3. Power supply 3.3.1. Feature of GSM power The unit of GSM transmit in the wireless path is pulse string which is constructed by GSMK bit string and we call it burst. The period of burst is 4.16ms and the last time of burst is 577us. The burst current will reach 1.6A while idle current is as low as tens of milliampere. This sudden change of current will produce large ripple of VBAT or pull the VBAT down to 3.3V, while the module will shut down when VBAT drops to 3.3V. Due to these features, the power design for the module is crucial. The following figure is the VBAT voltage and current ripple at the maximum power transmitting phase, the test condition is VBAT=4.0V, VBAT maximum output current =2A, C1=100µF tantalum capacitor (ESR=0.7Ω) and C2=1µF. Max:400mVBurst:1.6A4.615ms577usIBATVBAT Figure 3: Ripple in supply voltage during transmitting burst 3.3.2. Minimize supply voltage drop The power supply of the module is from a single voltage source of VBAT= 3.3V~4.6V. The GSM transmitting burst can cause obvious voltage drop at the supply voltage thus the power supply must be carefully designed and is capable of providing sufficient current up to 2A. For the VBAT input, a bypass capacitor of about 100µF with low ESR is recommended. Multi-layer ceramic chip (MLCC) capacitor can provide the best combination of low ESR but small size may not be economical. A lower cost choice could be a 100µF tantalum capacitor with low ESR. A small QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 28 - (0.1µF to 1µF) ceramic capacitor should be in parallel with the 100µF capacitor, which is illustrated in Figure 4. The capacitors should be placed close to the M35 VBAT pins. The PCB traces from the VBAT pads to the power source must be wide enough to ensure that there is not too much voltage drop occurring in the transmitting burst mode. The width of trace should be no less than 2mm and the principle of the VBAT trace is the longer, the wider. The VBAT voltage drop can be measured by oscilloscope. C2C1VBAT+ C1=100uF, C2=0.1uF~1uF Figure 4: Reference circuit of the VBAT input 3.3.3. Reference power design for the module The power design for the module is very important and the circuit design of the power supply for the module largely depends on the power source. Figure 5 shows a reference design of +5V input power source. The part number of this LDO IC is MIC29302WU. The designed output for the power supply is 4.16V and the maximum load current is 3A, in order to prevent outputting abnormal voltage, a zener voltage regulator is employed at the point of the output nearby the pin of VBAT. Some elements have to be taken into account in the component select, such as reserve zener voltage is recommend 5.1V and the total dissipation is more than 1Watt. C1100uFC2MIC29032 U1IN OUTENGNDADJ2 4135DC_IN VBAT100nFC3100uFC4100nFC5 C633pFR110pFD1120K51KR2 5.1V Figure 5: Reference circuit of the source power supply input QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 29 - 3.3.4. Monitor power supply To monitor the supply voltage, the “AT+CBC” command can be used which includes three parameters: charging status, remaining battery capacity and voltage value (in mV). It returns the 0-100 percent of battery capacity and actual value measured between VBAT and GND. The voltage is automatically measured in period of 5s. The displayed voltage (in mV) is averaged over the last measuring period before the “AT+CBC” command is executed. For details, please refer to document [1]. 3.4. Power on and down scenarios 3.4.1. Power on The module can be turned on by PWRKEY pin. The module is set to autobauding mode (AT+IPR=0) in default configuration. In the autobauding mode, the URC “RDY” after powering on is not sent to host controller. When the module receives AT command, it will be powered on after a delay of 2 or 3 seconds. Host controller should firstly send an “AT” or “at” string in order that the module can detect baud rate of host controller, and it should send the second or the third “AT” or “at” string until receiving “OK” string from module. Then an “AT+IPR=x;&W” should be sent to set a fixed baud rate for module and save the configuration to flash memory of module. After these configurations, the URC “RDY” would be received from the UART Port of module every time when the module is powered on. Refer to section “AT+IPR” in document [1]. The hardware flow control is disabled in default configuration. In the simple UART port which means that only TXD, RXD, GND of the module is connected to host. CTS is pulled down internally. In this condition, the module can transmit and receive data freely. On the other side, if RTS, CTS are connected to the host together with TXD, RXD, GND, whether or not to transmit and receive data depends on the level of RTS and CTS. Then whenever hardware flow is present or not, the URC “RDY” is sent to host controller in the fixed band rate. 3.4.1.1. Power on the module using the PWRKEY pin Customer’s application can turn on the module by driving the pin PWRKEY to a low level voltage and after STATUS pin outputs a high level, PWRKEY pin can be released. Customer may monitor the level of the STATUS pin to judge whether the module is power-on or not. An open collector driver circuit is suggested to control the PWRKEY. A simple reference circuit is illustrated in Figure 6. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 30 - Turn on pulsePWRKEY4.7K47K Figure 6: Turn on the module using driving circuit The other way to control the PWRKEY is using a button directly. A TVS component is indispensable to be placed nearby the button for ESD protection. When pressing the key, electrostatic strike may generate from finger. A reference circuit is showed in Figure 7. S1PWRKEYTVS1Close to S1 Figure 7: Turn on the module using keystroke The power-on scenarios is illustrated as the following figure. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 31 - VDD_EXT（OUTPUT）VIL<0.1*VBATVBATPWRKEY(INPUT)EMERG_OFF（INPUT）54ms250msSTATUS（OUTPUT）800ms1>1sVIH > 0.1*VBAT Figure 8: Timing of turning on system ① Make sure that VBAT is stable before pulling down PWRKEY pin. The time between them is recommended 30ms. Note: Customer can monitor the voltage level of the STATUS pin to judge whether the module is power-on. After the STATUS pin goes to high level, PWRKEY can be released. If the STATUS pin is ignored, pull the PWRKEY pin to low level for more than 1 second to turn on the module. 3.4.2. Power down The following procedures can be used to turn off the module:  Normal power down procedure: Turn off module using the PWRKEY pin  Normal power down procedure: Turn off module using command “AT+QPOWD”  Over-voltage or under-voltage automatic shutdown: Take effect when over-voltage or under-voltage is detected  Emergent power down procedure: Turn off module using the EMERG_OFF pin  Emergent power down procedure: Turn off module using command “AT+QPOWD” 3.4.2.1. Power down module using the PWRKEY pin Customer’s application can turn off the module by driving the PWRKEY to a low level voltage for certain time. The power-down scenarios is illustrated in Figure 9. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 32 - The power-down procedure causes the module to log off from the network and allows the software to save important data before completely disconnecting the power supply, thus it is a safe way. Before the completion of the power-down procedure, the module sends out the result code shown as below: NORMAL POWER DOWN Note: This result code does not appear when autobauding is active and DTE and DCE are not correctly synchronized after start-up. The module is recommended to set a fixed baud rate. After that moment, no further AT commands can be executed. Then the module enters the POWER DOWN mode, only the RTC is still active. The POWER DOWN mode can also be indicated by the STATUS pin, which is a low level voltage in this mode. PWRKEY（INPUT）STATUS（OUTPUT）1s > Pulldown > 0.6sLogout net about 2s to 12sVDD_EXT（OUTPUT）EMERG_OFF（OUTPUT）VBAT（OUTPUT）160us Figure 9: Timing of turning off the module QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 33 - 3.4.2.2. Power down the module using AT command Customer’s application can turn off the module via AT command “AT+QPOWD=1”. This command will let the module to log off from the network and allow the software to save important data before completely disconnecting the power supply, thus it is a safe way. Before the completion of the power-down procedure the module sends out the result code shown as below: NORMAL POWER DOWN After that moment, no further AT commands can be executed. And then the module enters the POWER DOWN mode, only the RTC is still active. The POWER DOWN mode can also be indicated by STATUS pin, which is a low level voltage in this mode. Please refer to document [1] for details about the AT command “AT+QPOWD”. 3.4.2.3. Over-voltage or under-voltage automatic shutdown The module will constantly monitor the voltage applied on the VBAT, if the voltage is ≤ 3.5V, the following URC will be presented: UNDER_VOLTAGE WARNING If the voltage is ≥ 4.5V, the following URC will be presented: OVER_VOLTAGE WARNING The uncritical voltage range is 3.3V to 4.6V. If the voltage is > 4.6V or <3.3V, the module would automatically shutdown itself. If the voltage is <3.3V, the following URC will be presented: UNDER_VOLTAGE POWER DOWN If the voltage is >4.6V, the following URC will be presented: OVER_VOLTAGE POWER DOWN Note: These result codes don’t appear when autobauding is active and DTE and DCE are not correctly synchronized after start-up. The module is recommended to set to a fixed baud rate. After that moment, no further AT commands can be executed. The module logs off from network and enters POWER DOWN mode, and only RTC is still active. The POWER DOWN mode can also be indicated by the pin STATUS, which is a low level voltage in this mode. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 34 - 3.4.2.4. Emergency shutdown using EMERG_OFF pin The module can be shut down by driving the pin EMERG_OFF to a low level voltage over 20ms and then releasing it. The EMERG_OFF line can be driven by an Open Drain / Collector driver or a button. The circuit is illustrated as the following figures. Emergency shutdown pulseEMERG_OFF4.7K47K Figure 10: Reference circuit for EMERG_OFF by using driving circuit S1EMERG_OFFTVS1Close to S1 Figure 11: Reference circuit for EMERG_OFF by using button 3.4.2.5. Emergency shutdown using AT command Using an AT command “AT+QPOWD=0” can achieve emergency shutdown of the module. In this situation, No URC returns back to the host no matter in the fixed band rate or auto band rate. Be cautious to use the pin EMERG_OFF. It should only be used under emergent situation. For instance, if the module is unresponsive or abnormal, the pin EMERG_OFF could be used to shut down the system. Although turning off the module by EMERG_OFF is fully tested and nothing wrong detected, this operation is still a big risk as it could cause destroying of the code or data area of the NOR flash memory in the module. Therefore, it is recommended that PWRKEY or AT command should always be the preferential way to turn off the system. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 35 - 3.4.3. Restart 3.4.3.1. Restart the module using the PWRKEY pin Customer’s application can restart the module by driving the PWRKEY to a low level voltage for certain time, which is similar to the way of turning on module. Before restarting the module, at least 500ms should be delayed after detecting the low level of STATUS. The restart timing is illustrated as the following figure. STATUS（OUTPUT）HPWRKEY（INPUT）Delay > 0.5sTurn offPull down the PWRKEY to turn on the moduleRestart Figure 12: Timing of restarting system The module can also be restarted by the PWRKEY after emergency shutdown. PWRKEY（INPUT）Pulldown >20ms Delay>2sEMERG_OFF（INPUT）STATUS（OUTPUT）6us Figure 13: Timing of restarting system after emergency shutdown 3.4.3.2. Restart the module using AT command Using an AT command “AT+QPOWD=2” can achieve restart of the module. Please refer to document [1] for the details. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 36 - 3.5. Power saving Upon system requirement, there are several actions to drive the module to enter low current consumption status. For example, “AT+CFUN” can be used to set module into minimum functionality mode and DTR hardware interface signal can be used to lead system to SLEEP mode. 3.5.1. Minimum functionality mode Minimum functionality mode reduces the functionality of the module to minimum level, thus minimize the current consumption when the slow clocking mode is activated at the same time. This mode is set with the “AT+CFUN” command which provides the choice of the functionality levels <fun>=0，1，4.  0: minimum functionality  1: full functionality (default)  4: disable both transmitting and receiving of RF part If the module is set to minimum functionality by “AT+CFUN=0”, the RF function and SIM card function would be disabled. In this case, the UART port is still accessible, but all AT commands correlative with RF function or SIM card function will not be accessible. If the module has been set by “AT+CFUN=4”, the RF function will be disabled, but the UART port is still active. In this case, all AT commands correlative with RF function will not be accessible. After the module is set by “AT+CFUN=0” or “AT+CFUN=4”, it can return to full functionality by “AT+CFUN=1”. For detailed information about “AT+CFUN”, please refer to document [1]. 3.5.2. Sleep mode The SLEEP mode is disabled in default software configuration. Customer’s application can enable this mode by “AT+QSCLK=1”. On the other hand, the default setting is “AT+QSCLK=0” and in this mode, the module cannot enter SLEEP mode. When “AT+QSCLK=1” is sent to the module, customer’s application can control the module to enter or exit from the SLEEP mode through pin DTR. When DTR is set to high level, and there is no on-air or hardware interrupt such as GPIO interrupt or data on UART port, the module will enter SLEEP mode automatically. In this mode, the module can still receive voice, SMS or GPRS paging from network but the UART port is not accessible. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 37 - 3.5.3. Wake up the module from SLEEP mode When the module is in the SLEEP mode, the following methods can wake up the module. If the DTR Pin is set low, it would wake up the module from the SLEEP mode. The UART port will be active within 20ms after DTR is changed to low level. Receiving a voice or data call from network wakes up module. Receiving an SMS from network wakes up module. Note: DTR pin should be held low level during communication between the module and DTE. 3.6. Summary of state transitions Table 8: Summary of state transition Current mode Next mode Power down Normal mode Sleep mode Power down Use PWRKEY Normal mode AT+QPOWD, use PWRKEY pin, or use EMERG_OFF pin Use AT command “AT+QSCLK=1” and pull DTR up Sleep mode Use PWRKEY pin, or use EMERG_OFF pin Pull DTR down or incoming call or SMS or GPRS 3.7. RTC backup The RTC (Real Time Clock) can be supplied by an external capacitor or battery (rechargeable or non-chargeable) through the pin VRTC. A 1.5 K resistor has been integrated in the module for current limiting. A coin-cell battery or a super-cap can be used to backup power supply for RTC. The following figures show various sample circuits for RTC backup. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 38 - RTCCore1.5KMODULEVRTCNon-chargeableBackup Battery Figure 14: RTC supply from non-chargeable battery RTCCore1.5KMODULEVRTCRechargeableBackup Battery Figure 15: RTC supply from rechargeable battery RTCCore1.5KMODULEVRTC Large-capacitance Capacitor Figure 16: RTC supply from capacitor Coin-type rechargeable capacitor such as XH414H-IV01E from Seiko can be used. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 39 - Figure 17: Seiko XH414H-IV01E Charge Characteristics 3.8. Serial interfaces The module provides two serial ports: UART and Debug Port. The module is designed as a DCE (Data Communication Equipment), following the traditional DCE-DTE (Data Terminal Equipment) connection. Autobauding function supports baud rate from 4800bps to 115200bps. The UART Port:  TXD: Send data to RXD of DTE  RXD: Receive data from TXD of DTE  RTS: Requests to send  CTS: Clear to send  DTR: DTE is ready and inform DCE (this pin can wake the module up)  RI: Ring indicator (when the call, SMS, data of the module are coming, the module will output signal to inform DTE)  DCD: Data carrier detection (the valid of this pin demonstrates the communication link is set up) The module disables hardware flow control in default. When hardware flow control is required, RTS and CTS should be connected to the host. AT command “AT+IFC=2,2” is used to enable hardware flow control. AT command “AT+IFC=0,0” is used to disable the hardware flow control. For more details, please refer to document [1]. The Debug Port  DBG_TXD: Send data to the COM port of a debugging computer  DBG_RXD: Receive data from the COM port of a debugging computer QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 40 - The logic levels are described in the following table. Table 9: Logic levels of the UART interface Parameter Min Max Unit VIL 0 0.25*VDD_EXT V VIH 0.75*VDD_EXT VDD_EXT +0.3 V VOL 0 0.15*VDD_EXT V VOH 0.85*VDD_EXT VDD_EXT V Table 10: Pin definition of the UART interfaces Interface Name Pin Function Debug Port DBG_RXD 14 Receive data of the debug port DBG_TXD 15 Transmit data of the debug port UART Port DTR 20 Data terminal ready RXD 21 Receive data of the UART port TXD 22 Transmit data of the UART port CTS 23 Clear to send RTS 24 Request to send DCD 25 Data carrier detection RI 26 Ring indicator 3.8.1. UART Port 3.8.1.1 The features of UART Port. Seven lines on UART interface Contain data lines TXD and RXD, hardware flow control lines RTS and CTS, other control lines DTR, DCD and RI Used for AT command, GPRS data, CSD FAX, etc. Multiplexing function is supported on the UART Port. So far only the basic mode of multiplexing is available. Support the communication baud rates as the following: 300,600,1200,2400,4800,9600,14400,19200,28800,38400,57600,115200. The default setting is autobauding mode. Support the following baud rates for autobauding function: 4800, 9600, 19200, 38400, 57600, 115200. The module disables hardware flow control in default, AT command “AT+IFC=2,2” is used to enable hardware flow control After setting a fixed baud rate or autobauding, please send “AT” string at that rate. The UART port is ready when it responds “OK”. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 41 - Autobauding allows the module to detect the baud rate by receiving the string “AT” or “at” from the host or PC automatically, which gives module flexibility without considering which baud rate is used by the host controller. Autobauding is enabled in default. To take advantage of the autobauding mode, special attention should be paid according to the following requirements: Synchronization between DTE and DCE: When DCE (the module) powers on and the autobauding is enabled, it is recommended to wait 2 to 3 seconds before sending the first AT character. After receiving the “OK” response, DTE and DCE are correctly synchronized. If the host controller needs URC in the mode of autobauding, it must be synchronized firstly. Otherwise the URC will be discarded. Restrictions on autobauding operation  The UART port has to be operated at 8 data bits, no parity and 1 stop bit (factory setting).  The A/ and a/ commands can’t be used.  Only the strings “AT” or “at” can be detected (neither “At” nor “aT”).  The Unsolicited Result Codes like "RDY", "+CFUN: 1" and "+CPIN: READY” will not be indicated when the module is turned on with autobauding enabled and not be synchronized.  Any other Unsolicited Result Codes will be sent at the previous baud rate before the module detects the new baud rate by receiving the first “AT” or “at” string. The DTE may receive unknown characters after switching to new baud rate.  It is not recommended to switch to autobauding from a fixed baud rate.  If autobauding is active it is not recommended to switch to multiplex mode Note: To assure reliable communication and avoid any problems caused by undetermined baud rate between DCE and DTE, it is strongly recommended to configure a fixed baud rate and save it instead of using autobauding after start-up. For more details, please refer to Section “AT+IPR” in document [1]. 3.8.1.2. The connection of UART The connection between module and host via UART port is very flexible. Three connection styles are illustrated as below. UART Port connection is shown as below when it is applied in modulation-demodulation. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 42 - TXDRXDRTSCTSDTRDCDRITXDRXDRTSCTSDTRDCDRIModule (DCE)PC (DTE)UART portUART PortGND GND Figure 18: Connection of all functional UART port Three lines connection is shown as below. Host(DTE) Controller TXD RXD GND Module(DCE)TXDRXDGNDUART PortRTS0R Figure 19: Connection of three lines UART port UART Port with hardware flow control is shown as below. This connection will enhance the reliability of the mass data communication. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 43 - Host(DTE) Controller Module(DCE)RTSCTSRTSGNDGNDRXDTXDUART PortCTSRXDTXD Figure 20: Connection of UART port associated hardware flow control 3.8.1.3. Software upgrade The TXD, RXD can be used to upgrade software. The PWRKEY pin must be pulled down before the software upgrades. Please refer to the following figures for software upgrade. IO Connector TXDRXDGNDPWRKEY Module (DCE ) UART Port TXD RXD GND PWRKEY Figure 21: Connection of software upgrade QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 44 - 3.8.2. Debug Port Debug Port  Two lines: DBG_TXD and DBG_RXD  It outputs log information automatically.  Debug Port is only used for software debugging and its baud rate must be configured as 460800bps. Debug Computer TXD RXD GND Module(DCE) Debug port DBG_TXD DBG_RXD GND Figure 22: Connection of software debug 3.8.3. UART Application The reference design of 3.3V level match is shown as below. 1K and 5.6K resistors among the following diagram are used to decrease the output voltage of MCU/ARM. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 45 - MCU/ARM MODULE/TXD/RXD TXDRXDRTSCTSDTRRI/RTS/CTSGPIOEINTvoltage level: 3.3VGPIO DCD1K1K1K1K1K5K6 5K6 5K61K1K Figure 23: 3.3V level match circuit Note: 5.6K resistors among the above diagram need to be changed to 15K resistors for 3V system. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 46 - The reference design of 5V level match is shown as below. The construction of dotted line can refer to the construction of solid line. Please pay attention to direction of connection. Input dotted line of module should refer to input solid line of the module. Output dotted line of module should refer to output solid line of the module. MCU/ARM/TXD/RXD1KVDD_EXT4.7kVCC_MCU4.7k4.7k4.7kVDD_EXTTXDRXDRTSCTSDTRRI/RTS/CTSvoltage level: 5VGNDVBATGPIO STATUSMODULEGPIOEINTVCC_MCU Figure 24: 5V level match circuit QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 47 - The following picture is an example of connection between module and PC. A RS_232 level shifter IC or circuit must be inserted between module and PC, since these three UART ports don’t support the RS_232 level, while support the CMOS level only. 98765432115148911125761042622713182021161719222324312528GNDTO PC serial portSP32383VGNDGNDT5OUT/SHUTDOWNV+GNDV-VCCT4OUTT2OUTT3OUTT1OUTR3INR2INR1IN/STATUS3V ONLINER1OUTR2OUTR3OUT/R1OUTGND T5INT4INT3INT2INT1INC2+C2-C1-C1+MODULERXDDTRRTSRICTSTXDDCD Figure 25: RS232 level match circuit QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 48 - 3.9. Audio interfaces The module provides two analogy input channels and three analogy output channels. Table 11: Pin definition of Audio interface AIN1 and AIN2 can be used for input of microphone and line. An electret microphone is usually used. AIN1 and AIN2 are both differential input channels. AOUT1 is used for output of the receiver and speaker. This channel is typically used for a receiver built into a handset. AOUT1 channel is a differential channel. It only supports voice path. If it is used as a speaker, an amplifier should be employed. AOUT2 is used for loud speaker output as it is embedded an amplifier of class AB whose maximum drive power is 800mW. AOUT2 is a differential channel. Immediately playing Melody or Midi ring tone for incoming call is available in AOUT2. AOUT2 also can be used for output of earphone, which can be used as a single-ended channel. LOUDSPKP and AGND can establish a pseudo differential mode. These two audio channels can be swapped by “AT+QAUDCH” command. For more details, please refer to document [1]. Use AT command “AT+QAUDCH” to select audio channel:  0--AIN1/AOUT1, the default value is 0.  2--AIN2/AOUT2 For each channel, customer can use AT+QMIC to adjust the input gain level of microphone. Customer can also use “AT+CLVL” to adjust the output gain level of receiver and speaker. “AT+QECHO” is used to set the parameters for echo cancellation control. “AT+QSIDET” is used to set the side-tone gain level. For more details, please refer to document [1]. Interface Name Pin Function AIN1/AOUT1 MIC1P 4 Channel one of Microphone positive input MIC1N 5 Channel one of Microphone negative input SPK1N 6 Channel one of Audio negative output SPK1P 7 Channel one of Audio positive output AIN2/AOUT2 MIC2P 2 Channel two of Microphone positive input MIC2N 3 Channel two of Microphone negative input AGND 1 Cooperate with LOUDSPKP LOUDSPKP 9 Channel two of Audio positive output LOUDSPKN 8 Channel two of Audio negative output QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 49 - Table 12: AOUT2 output characteristics Item Condition min type max unit RMS power 8ohm load VBAT=4.3V THD+N=1% 800 mW 8ohm load VBAT=3.7V THD+N=1% 700 mW 8ohm load VBAT=3.3V THD+N=1% 500 mW Gain adjustment range 0 18 dB Gain adjustment steps 3 dB 3.9.1. Decrease TDD noise and other noise The 33pF capacitor is applied for filtering out 900MHz RF interference when the module is transmitting at GSM900MHz. Without placing this capacitor, TDD noise could be heard. Moreover, the 10pF capacitor here is for filtering out 1800MHz RF interference. However, the resonant frequency point of a capacitor largely depends on the material and production technique. Therefore, customer would have to discuss with its capacitor vendor to choose the most suitable capacitor for filtering out GSM850MHz, GSM900MHz, DCS1800MHz and PCS1900MHz separately. The severity degree of the RF interference in the voice channel during GSM transmitting period largely depends on the application design. In some cases, GSM900 TDD noise is more severe; while in other cases, DCS1800 TDD noise is more obvious. Therefore, customer can have a choice based on test results. Sometimes, even no RF filtering capacitor is required. The capacitor which is used for filtering out RF noise should be close to RJ11 or other audio interfaces. Audio alignment should be as short as possible. In order to decrease radio or other signal interference, the position of RF antenna should be kept away from audio interface and audio alignment. Power alignment and audio alignment should not be parallel, and power alignment should be far away from audio alignment. The differential audio traces have to be placed according to the differential signal layout rule. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 50 - 3.9.2. Microphone interfaces design AIN1/IN2 channels come with internal bias supply for external electret microphone. A reference circuit is shown in Figure 26. MICxPDifferential layoutModule 10pF 33pF33pF33pFGNDGNDElectret MicrophoneGNDGND10pF10pFGNDGNDESD ANTIESDANTI33pF10pFClose to ModuleMICxNGNDGNDGNDGND10pF 33pF33pF10pFClose to MIC Figure 26: Microphone interface design of AIN1&AIN2 3.9.3. Receiver interface design SPK1PSPK1NDifferential layout10pF10pF33pF33pF33pFGNDGND10pFESD ANTIESD ANTIModuleClose to ReceiverGNDGNDGND GND Figure 27: Receiver interface design of AOUT1 QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 51 - 3.9.4. Earphone interface design 1243MIC2P22uF68R33pFGND GNDAGNDClose to Socket33pFAGND33pF 10pFGND GNDGNDGNDAGNDModule4.7uFLOUDSPKPClose to ModuleGNDGNDGNDGND10pF 33pF33pF10pFDifferential layout33pF10pFMIC2N0RAmphenol9001-8905-050 Figure 28: Earphone interface design 3.9.5. Loud speaker interface design LOUDSPKNDifferential layout10pF10pF 33pF33pFGNDGNDESD ANTIESD ANTI0R0RLOUDSPKPGNDGNDGND GND10pF 33pF8 ohmClose to SpeakerModule Figure 29: Loud speaker interface design QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 52 - 3.9.6. Audio characteristics Table 13: Typical electret microphone characteristics Parameter Min Typ Max Unit Working Voltage 1.2 1.5 2.0 V Working Current 200 500 uA External Microphone Load Resistance 2.2 k Ohm Table 14: Typical speaker characteristics Parameter Min Typ Max Unit Normal Output (AOUT1) Single Ended Load Resistance 28 32 Ohm Ref level 0 2.4 Vpp Differential Load Resistance 28 32 Ohm Ref level 0 4.8 Vpp Auxiliary Output (AOUT2) Single Ended Load Resistance 8 Load Resistance Ref level 0 VBAT Vpp Differential Load Resistance 8 Load Resistance Ref level 0 2*VBAT Vpp 3.10. SIM card interface 3.10.1. SIM card application The SIM interface supports the functionality of the GSM Phase 1 specification and also supports the functionality of the new GSM Phase 2+ specification for FAST 64 kbps SIM card, which is intended for use with a SIM application Tool-kit. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 53 - The SIM interface is powered from an internal regulator in the module. Both 1.8V and 3.0V SIM Cards are supported. Table 15: Pin definition of the SIM interface The reference circuit using a 6-pin SIM card holder is illustrated as the following figure. Module22R22R22RC707 10M006 512 2SIM CARDGNDSIM_VDDSIM_RSTSIM_CLKSIM_DATASIM_GND100nFVCCRSTCLKGNDVPPIO Figure 30: Reference circuit of the 6 pins SIM card The following design rules can optimize the SIM interface performance and protect the SIM card effectively. The rules should be taken into account in designing the circuit. Place the SIM card holder close to module as close as possible. Ensure the trace length of SIM signals keeps less than 200mm.  Keep the SIM signals far away from VBAT power and RF trace.  The width of SIM_VDD and SIM_GND trace is not less than 0.5mm. Place a bypass capacitor close to SIM card power pin. The value of capacitor is less than 1uF. Name Pin Function SIM_VDD 27 Supply power for SIM Card. Automatic detection of SIM card voltage. 3.0V±10% and 1.8V±10%. Maximum supply current is around 10mA. SIM_RST 28 SIM Card reset SIM_DATA 29 SIM Card data I/O SIM_CLK 30 SIM Card clock SIM_GND 31 SIM Card ground QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 54 -  To avoid possible cross-talk from the SIM_CLK signal to the SIM_DATA signal be careful that both traces are not placed closely next to each other. The traces of SIM_CLK, SIM_DATA and SIM_RST are recommended to be around with GND independently. All signals of SIM interface should be protected against ESD with a TVS diode array. It is recommended to add TVS diode such as WILL (http://www.willsemi.com) ESDA6V8AV6. The parasitic capacitance of TVS diode is less than 50pF. The 22Ω resistors should be added in series between the module and the SIM card so as to suppress the EMI spurious transmission and enhance the ESD protection.  All the peripheral components are recommended to place near the SIM card holder. 3.10.2. 6 Pin SIM cassette For 6-pin SIM card holder, it is recommended to use Amphenol C707 10M006 512 2. Please visit http://www.amphenol.com for more information. Figure 31: Amphenol C707 10M006 512 2 SIM card holder Table 16: Pin description of Amphenol SIM card holder Name Pin Function SIM_VDD C1 SIM Card Power Supply SIM_RST C2 SIM Card Reset SIM_CLK C3 SIM Card Clock GND C5 Ground QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 55 - VPP C6 Not Connect SIM_DATA C7 SIM Card data I/O 3.12. Behaviors of the RI Table 17: Behaviors of the RI State RI respond Standby HIGH Voice calling Change to LOW, then: (1) Change to HIGH when call is established. (2) Use ATH to hang up the call, change to HIGH. (3) Calling part hangs up, change to HIGH first, and change to LOW for 120ms indicating “NO CARRIER” as an URC, then change to HIGH again. (4) Change to HIGH when SMS is received. Data calling Change to LOW, then： (1) Change to HIGH when data connection is established. (2) Use ATH to hang up the data calling, change to HIGH. (3) Calling part hangs up, change to HIGH first, and change to LOW for 120ms indicating “NO CARRIER” as an URC, then change to HIGH again. (4) Change to HIGH when SMS is received. SMS When a new SMS comes, the RI changes to LOW and holds low level for about 120 ms, then changes to HIGH. URC Certain URCs can trigger 120ms low level on RI. For more details, please refer to the document [10]. If the module is used as a caller, the RI would maintain high except the URC or SMS is received. On the other hand, when it is used as a receiver, the timing of the RI is shown below. RIIdle RingOff-hook by “ATA”. On-hook by “ATH”. SMS received. HIGHLOW Figure 32: RI behavior of voice calling as a receiver QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 56 - RIIdle RingData calling establish. On-hook by “ATH”. SMS receivedHIGHLOW Figure 33: RI behavior of data calling as a receiver RIIdle Calling On-hookTalkingHIGHLOWIdle Figure 34: RI behavior as a caller RIIdle or talking URC or SMS Received HIGHLOW120ms Figure 35: RI behavior of URC or SMS received QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 57 - 3.13. Network status indication The NETLIGHT signal can be used to drive a network status indication LED. The working state of this pin is listed in Table 18. Table 18: Working state of the NETLIGHT State Module function Off The module is not running. 64ms On/ 800ms Off The module is not synchronized with network. 64ms On/ 2000ms Off The module is synchronized with network. 64ms On/ 600ms Off GPRS data transfer is ongoing. A reference circuit is shown in Figure 36. Module 300R4.7K47KVBATNETLIGHT Figure 36: Reference circuit of the NETLIGHT 3.14. Operating status indication The STATUS pin is set as an output pin and can be used to judge whether module is power-on. In customer’s design, this pin can be connected to a GPIO of DTE or be used to drive an LED in order to judge the module’s operation status. A reference circuit is shown in Figure 37. Table 19: Pin definition of the STATUS Name Pin Function STATUS 12 Indication of module operating status QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 58 - Module 300R4.7K47KVBATSTATUS Figure 37: Reference circuit of the STATUS QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 59 - 4. Antenna interface The Pin 39 is the RF antenna pad. The RF interface has an impedance of 50Ω. Table 20: Pin definition of the Antenna interface 4.1. RF reference design The RF external circuit is recommended as below: RF_ANT0RMODULE NMNM Figure 38: Reference circuit of RF M35 provides an RF antenna PAD for customer’s antenna connection. The RF trace in host PCB connected to the module RF antenna pad should be micro-strip line or other types of RF trace, whose characteristic impendence should be close to 50Ω. M35 comes with grounding pads which are next to the antenna pad in order to give a better grounding. To minimize the loss on the RF trace and RF cable, take design into account carefully. It is recommended that the insertion loss should meet the following requirements:  GSM850/EGSM900 is <1dB.  DCS1800/PCS1900 is <1.5dB. Name Pin Function GND 37 ground GND 38 ground RF_ANT 39 RF antenna pad GND 40 ground QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 60 - 4.2. RF output power Table 21: The module conducted RF output power Frequency Max Min GSM850 33dBm ±2dB 5dBm±5dB EGSM900 33dBm ±2dB 5dBm±5dB DCS1800 30dBm ±2dB 0dBm±5dB PCS1900 30dBm ±2dB 0dBm±5dB Note: In GPRS 4 slots TX mode, the max output power is reduced by 2.5dB. This design conforms to the GSM specification as described in section 13.16 of 3GPP TS 51.010-1. 4.3. RF receiving sensitivity Table 22: The module conducted RF receiving sensitivity Frequency Receive sensitivity GSM850 < -108.5dBm EGSM900 < -108.5dBm DCS1800 < -108.5dBm PCS1900 < -108.5dBm 4.4. Operating frequencies Table 23: The module operating frequencies Frequency Receive Transmit ARFCH GSM850 869~894MHz 824~849MHz 128~251 EGSM900 925~960MHz 880~915MHz 0~124, 975~1023 DCS1800 1805~1880MHz 1710~1785MHz 512~885 PCS1900 1930~1990MHz 1850~1910MHz 512~810 4.5. RF cable soldering Soldering the RF cable to RF pad of module correctly will reduce the loss on the path of RF, refer to the following example of RF soldering. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 61 - Figure 39: RF soldering sample QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 62 - 5. Electrical, reliability and radio characteristics 5.1. Absolute maximum ratings Absolute maximum ratings for power supply and voltage on digital and analog pins of module are listed in the following table: Table 24: Absolute maximum ratings Parameter Min Max Unit VBAT -0.3 +4.73 V Peak current of power supply 0 2 A RMS current of power supply (during one TDMA- frame) 0 0.7 A Voltage at digital pins -0.3 3.3 V Voltage at analog pins -0.3 3.0 V Voltage at digital/analog pins in POWER DOWN mode -0.25 0.25 V 5.2. Operating temperature The operating temperature is listed in the following table: Table 25: Operating temperature Parameter Min Typ Max Unit Normal Temperature -35 25 80 ℃ Restricted Operation1) -40 ~ -35 80 ~ 85 ℃ Storage Temperature -45 +90 ℃ 1) When the module works above temperature range, the deviations from the GSM specification may occur. For example, the frequency error or the phase error will be increased. 5.3. Power supply ratings Table 26: The module power supply ratings Parameter Description Conditions Min Typ Max Unit VBAT Supply voltage Voltage must stay within the min/max values, including voltage drop, ripple, and spikes. 3.3 4.0 4.6 V QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 63 - Voltage drop during transmitting burst Maximum power control level on GSM850 and GSM900. 400 mV Voltage ripple Maximum power control level on GSM850 and GSM900 @ f<200kHz @ f>200kHz 50 2 mVmV IVBAT Average supply current POWER DOWN mode SLEEP mode @ DRX=5 30 0.9 uA mA IDLE mode GSM850/EGSM 900 DCS1800/PCS1900 13 13 mA mA TALK mode GSM850/EGSM 9001) DCS1800/PCS19002) 206/214 153/152 mA mA Peak supply current (during transmission slot) Maximum power control level on GSM850 and GSM900. 1.5 2 A 1) Power control level PCL 5 2) Power control level PCL 0 5.4. Current consumption The values of current consumption are shown in Table 27. Table 27: The module current consumption Condition Current Consumption Voice Call GSM850 @power level #5 <300mA,Typical 206mA @power level #12,Typical 95mA @power level #19,Typical 73mA GSM900 @power level #5 <300mA,Typical 214mA @power level #12,Typical 74mA @power level #19,Typical 73mA DCS1800 @power level #0 <250mA,Typical 153mA @power level #7,Typical 82mA QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 64 - @power level #15,Typical 69mA PCS1900 @power level #0 <250mA,Typical 153mA @power level #7,Typical 82mA @power level #15,Typical 70mA 5.5. Electro-static discharge Although the GSM engine is generally protected against Electrostatic Discharge (ESD), ESD protection precautions should still be emphasized. Proper ESD handling and packaging procedures must be applied throughout the processing, handling and operation of any applications using the module. The measured ESD values of module are shown as the following table: Table 28: The ESD endurance (Temperature:25℃,Humidity:45 %) Tested point Contact discharge Air discharge VBAT,GND ±5KV ±10KV RF_ANT ±5KV ±10KV TXD, RXD ±4KV ±8KV Others ±0.5KV ±1KV QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 65 - 6. Mechanical dimensions This chapter describes the mechanical dimensions of the module. 6.1. Mechanical dimensions of module Figure 40: M35 top and side dimensions（Unit: mm） QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 66 - 1Figure 41: M35 bottom dimensions（Unit: mm） QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 67 - 6.2. Footprint of recommendation BBAASilksreen Silksreenframe line frame line Figure 42: Footprint one of recommendation（Unit: mm） Note： 1. The blue pads are used for reserved pins customs can design the PCB decal without them. 2. To maintain the module, keep about 3mm away between the module and other components in host PCB. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 68 - 6.3. Top view of the module Figure 43: Top view of the module QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 69 - 6.4. Bottom view of the module Figure 44: Bottom view of the module QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 70 - 7. Storage and Manufacturing 7.1. Storage M35 is distributed in vacuum-sealed bag. The restriction of storage condition is shown as below. Shelf life in sealed bag: 12 months at <40 ºC / 90%RH After this bag is opened, devices that will be subjected to reflow solder or other high temperature process must be:  Mounted within 72 hours at factory conditions of ≤30 ºC /60% RH  Stored at <10% RH Devices require bake, before mounting, if:  Humidity indicator card is >10% when read 23 ºC ±5 ºC  Mounted for more than 72 hours at factory conditions of ≤30 ºC /60% RH If baking is required, devices may be baked for 48 hours at 125 ºC ±5 ºC Note: As plastic container cannot be subjected to high temperature, devices must be removed prior to high temperature (125 ºC ) bake. If shorter bake times are desired, please refer to IPC/JEDECJ-STD-033 for bake procedure. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 71 - 7.2. Soldering The squeegee should push the paste on the surface of the stencil that makes the paste fill the stencil openings and penetrate to the PCB. The force on the squeegee should be adjusted so as to produce a clean stencil surface on a single pass. To ensure the module soldering quality, the thickness of stencil at the hole of the module pads should be 0.2mm for M35. Figure 45: Paste application Suggest peak reflow temperature is from 235 ºC to 245 ºC (for SnAg3.0Cu0.5 alloy). Absolute max reflow temperature is 260 ºC. To avoid damage to the module when it was repeatedly heated, it is suggested that the module should be mounted after the first panel has been reflowed. The following picture is the actual diagram which we have operated. QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 72 - Time(s)50 100 150 200 250 30050100150200250 160℃ 200℃217070s~120s40s~60sBetween 1~3℃/SPreheat Heating Cooling℃sLiquids Temperature Figure 46: Ramp-Soak-Spike reflow profile 7.3. Packaging M35 modules are distributed in trays of 25 pieces each. This is especially suitable for the M35 according to SMT processes requirements. The trays are stored inside a vacuum-sealed bag which is ESD protected. It should not be opened until the devices are ready to be soldered onto the application. Figure 47: Module tray QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 73 - Appendix A: GPRS coding schemes Four coding schemes are used in GPRS protocol. The differences between them are shown in Table 29. Table 29: Description of different coding schemes Scheme Code rate USF Pre-coded USF Radio Block excl.USF and BCS BCS Tail Coded bits Punctured bits Data rate Kb/s CS-1 1/2 3 3 181 40 4 456 0 9.05 CS-2 2/3 3 6 268 16 4 588 132 13.4 CS-3 3/4 3 6 312 16 4 676 220 15.6 CS-4 1 3 12 428 16 - 456 - 21.4 Radio block structure of CS-1, CS-2 and CS-3 is shown as Figure 48: Figure 48: Radio block structure of CS-1, CS-2 and CS-3 Radio block structure of CS-4 is shown as Figure 49: Figure 49: Radio block structure of CS-4 Rate 1/2 convolutional coding Puncturing 456 bits USF BCS Radio Block block code No coding USF BCS Radio Block 456 bits QuectelConfidential
M35 Hardware Design M35_HD_V1.0 - 74 - Appendix B: GPRS multi-slot classes Twenty-nine classes of GPRS multi-slot modes are defined for MS in GPRS specification. Multi-slot classes are product dependant, 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 Table 30. Table 30: 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 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 QuectelConfidential
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