Quectel Wireless Solutions 201511M85 GSM/GPRS Module User Manual

Quectel Wireless Solutions Company Limited GSM/GPRS Module

User manual

M85 Hardware Design GSM/GPRS Module Series Rev. M85_Hardware_Design_V3.0 Date: 2015-10-22 www.quectel.com
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 1 / 88 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 Mail: info@quectel.com Or our local office, for more information, please visit: http://www.quectel.com/support/salesupport.aspx For technical support, to report documentation errors, please visit: http://www.quectel.com/support/techsupport.aspx Or Email: Support@quectel.com GENERAL NOTES QUECTEL OFFERS THIS 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 THIS INFORMATION CONTAINED HERE IS PROPRIETARY TECHNICAL INFORMATION OF QUECTEL CO., LTD. TRANSMITTABLE, REPRODUCTION, DISSEMINATION AND EDITING OF THIS DOCUMENT AS WELL AS UTILIZATION OF THIS CONTENTS 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. 2015. All rights reserved.
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 2 / 88 About the Document History Revision Date Author Description 1.0 2012-07-15 Winter CHEN Initial 1.1 2013-11-04 Felix YIN Optimized the parameters of VBAT ripple in Table 33 3.0 2015-03-13 Stone YU/ Hollis WANG 1. Updated module key features in Table 1 2. Modified pin assignment in Figure 2 3. Updated DC characteristics of module’s pins in Table 4 4. Updated reference circuit for power supply in Figure 5 5. Modified over-voltage or under-voltage automatic shutdown in Section 3.4.2.3 6. Modified RTC backup in Section 3.6 7. Modified UART application in Section 3.7.4 8. Deleted the data call mode in Section 3.13 9. Added antenna requirement in Section 4.5
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 3 / 88 Contents About the Document ................................................................................................................................... 2 Contents ....................................................................................................................................................... 3 Table Index ................................................................................................................................................... 6 Figure Index ................................................................................................................................................. 7 1 Introduction .......................................................................................................................................... 9 1.1. Safety Information ................................................................................................................. 10 2 Product Concept ................................................................................................................................ 11 2.1. General Description ............................................................................................................... 11 2.2. Directives and Standards ...................................................................................................... 11 2.2.1. FCC Statement ............................................................................................................... 11 2.2.2. FCC Radiation Exposure Statement .............................................................................. 12 2.3. Key Features ......................................................................................................................... 12 2.4. Functional Diagram ............................................................................................................... 14 2.5. Evaluation Board ................................................................................................................... 15 3 Application Interface ......................................................................................................................... 16 3.1. Pin of Module ......................................................................................................................... 17 3.1.1. Pin Assignment .............................................................................................................. 17 3.1.2. Pin Description ............................................................................................................... 18 3.2. Operating Modes ................................................................................................................... 23 3.3. Power Supply ........................................................................................................................ 24 3.3.1. Power Features of Module ............................................................................................. 24 3.3.2. Decrease Supply Voltage Drop ...................................................................................... 24 3.3.3. Reference Design For Power Supply ............................................................................ 25 3.3.4. Monitor Power Supply .................................................................................................... 26 3.4. Power On and Down Scenarios ............................................................................................ 26 3.4.1. Power On ....................................................................................................................... 26 3.4.2. Power Down ................................................................................................................... 28 3.4.2.1. Power Down Module Using the PWRKEY Pin ................................................ 28 3.4.2.2. Power Down Module Using AT Command ...................................................... 29 3.4.2.3. Over-voltage or Under-voltage Automatic Shutdown ...................................... 29 3.4.2.4. Emergency Shutdown Using EMERG_OFF Pin ............................................. 30 3.4.3. Restart ............................................................................................................................ 31 3.5. Power Saving ........................................................................................................................ 32 3.5.1. Minimum Functionality Mode ......................................................................................... 32 3.5.2. SLEEP Mode .................................................................................................................. 33 3.5.3. Wake up Module from SLEEP Mode ............................................................................. 33 3.5.4. Summary of State Transition .......................................................................................... 33 3.6. RTC Backup .......................................................................................................................... 34
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 4 / 88 3.7. Serial Interfaces ..................................................................................................................... 36 3.7.1. UART Port ...................................................................................................................... 38 3.7.1.1. The Features of UART Port ............................................................................. 38 3.7.1.2. The Connection of UART Port ......................................................................... 39 3.7.1.3. Firmware Upgrade ........................................................................................... 40 3.7.2. Debug Port ..................................................................................................................... 41 3.7.3. Auxiliary UART Port ....................................................................................................... 42 3.7.4. UART Application ........................................................................................................... 42 3.8. Audio Interfaces ..................................................................................................................... 44 3.8.1. Decrease TDD Noise and Other Noise .......................................................................... 45 3.8.2. Microphone Interfaces Design ....................................................................................... 46 3.8.3. Receiver and Speaker Interface Design ........................................................................ 46 3.8.4. Earphone Interface Design ............................................................................................ 48 3.8.5. Loud Speaker Interface Design...................................................................................... 49 3.8.6. Audio Characteristics ..................................................................................................... 49 3.9. SIM Card Interfaces .............................................................................................................. 50 3.10. SD Card Interface .................................................................................................................. 53 3.11. PCM Interface ........................................................................................................................ 55 3.11.1. Configuration .................................................................................................................. 56 3.11.2. Timing ............................................................................................................................. 56 3.11.3. Reference Design .......................................................................................................... 58 3.11.4. AT Command ................................................................................................................. 58 3.12. ADC ....................................................................................................................................... 59 3.13. Behaviors Of The RI .............................................................................................................. 60 3.14. Network Status Indication ...................................................................................................... 62 3.15. Operating Status Indication ................................................................................................... 62 4 Antenna Interface ............................................................................................................................... 64 4.1. Reference Design .................................................................................................................. 64 4.2. RF Output Power ................................................................................................................... 65 4.3. RF Receiving Sensitivity ........................................................................................................ 65 4.4. Operating Frequencies .......................................................................................................... 66 4.5. Antenna Requirement ........................................................................................................... 66 4.6. RF Cable Soldering ............................................................................................................... 67 5 Electrical, Reliability and Radio Characteristics ............................................................................ 68 5.1. Absolute Maximum Ratings................................................................................................... 68 5.2. Operating Temperature ......................................................................................................... 69 5.3. Power Supply Ratings ........................................................................................................... 69 5.4. Current Consumption ............................................................................................................ 70 5.5. Electro-static Discharge ........................................................................................................ 72 6 Mechanical Dimensions .................................................................................................................... 74 6.1. Mechanical Dimensions of Module ....................................................................................... 74 6.2. Recommended Footprint ....................................................................................................... 76 6.3. Top View of the Module ......................................................................................................... 77
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 5 / 88 6.4. Bottom View of the Module ................................................................................................... 77 7 Storage and Manufacturing .............................................................................................................. 78 7.1. Storage .................................................................................................................................. 78 7.2. Soldering ............................................................................................................................... 79 7.3. Packaging .............................................................................................................................. 80 8 Appendix A Reference ....................................................................................................................... 82 9 Appendix B GPRS Coding Scheme ................................................................................................. 87 10 Appendix C GPRS Multi-slot Class .................................................................................................. 89
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 6 / 88 Table Index TABLE 1: MODULE KEY FEATURES ............................................................................................................... 12 TABLE 2: CODING SCHEMES AND MAXIMUM NET DATA RATES OVER AIR INTERFACE ........................ 14 TABLE 3: PIN DESCRIPTION ........................................................................................................................... 18 TABLE 4: OVERVIEW OF OPERATING MODES ............................................................................................. 23 TABLE 5: SUMMARY OF STATE TRANSITION ............................................................................................... 33 TABLE 6: LOGIC LEVELS OF THE UART INTERFACE .................................................................................. 37 TABLE 7: PIN DEFINITION OF THE UART INTERFACES .............................................................................. 37 TABLE 8: PIN DEFINITION OF AUDIO INTERFACE ....................................................................................... 44 TABLE 9: AOUT3 OUTPUT CHARACTERISTICS ............................................................................................ 45 TABLE 10: TYPICAL ELECTRET MICROPHONE CHARACTERISTICS ......................................................... 49 TABLE 11: TYPICAL SPEAKER CHARACTERISTICS ..................................................................................... 49 TABLE 12: PIN DEFINITION OF THE SIM INTERFACE .................................................................................. 50 TABLE 13: PIN DEFINITION OF THE SD CARD INTERFACE ........................................................................ 54 TABLE 14: PIN DEFINITION OF THE SD CARD INTERFACE ........................................................................ 54 TABLE 15: PIN DEFINITION OF PCM INTERFACE ......................................................................................... 55 TABLE 16: CONFIGURATION ........................................................................................................................... 56 TABLE 17: QPCMON COMMAND DESCRIPTION .......................................................................................... 59 TABLE 18: QPCMVOL COMMAND DESCRIPTION ......................................................................................... 59 TABLE 19: PIN DEFINITION OF THE ADC ...................................................................................................... 60 TABLE 20: CHARACTERISTICS OF THE ADC ................................................................................................ 60 TABLE 21: BEHAVIORS OF THE RI ................................................................................................................. 60 TABLE 22: WORKING STATE OF THE NETLIGHT .......................................................................................... 62 TABLE 23: PIN DEFINITION OF THE STATUS ................................................................................................ 63 TABLE 24: PIN DEFINITION OF THE RF_ANT ................................................................................................ 64 TABLE 25: THE MODULE CONDUCTED RF OUTPUT POWER .................................................................... 65 TABLE 26: THE MODULE CONDUCTED RF RECEIVING SENSITIVITY ....................................................... 65 TABLE 27: THE MODULE OPERATING FREQUENCIES ................................................................................ 66 TABLE 28: ANTENNA CABLE REQUIREMENTS ............................................................................................. 66 TABLE 29: ANTENNA REQUIREMENTS .......................................................................................................... 66 TABLE 30: ABSOLUTE MAXIMUM RATINGS .................................................................................................. 68 TABLE 31: OPERATING TEMPERATURE ........................................................................................................ 69 TABLE 32: THE MODULE POWER SUPPLY RATINGS .................................................................................. 69 TABLE 33: THE MODULE CURRENT CONSUMPTION .................................................................................. 70 TABLE 34: THE ESD ENDURANCE (TEMPERATURE: 25ºC , HUMIDITY: 45%) ............................................ 73 TABLE 35: REEL PACKING .............................................................................................................................. 81 TABLE 36: RELATED DOCUMENTS ................................................................................................................ 82 TABLE 37: TERMS AND ABBREVIATIONS ...................................................................................................... 83 TABLE 38: DESCRIPTION OF DIFFERENT CODING SCHEMES .................................................................. 87 TABLE 39: GPRS MULTI-SLOT CLASSES ...................................................................................................... 89
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 7 / 88 Figure Index FIGURE 1: MODULE FUNCTIONAL DIAGRAM ............................................................................................... 15 FIGURE 2: PIN ASSIGNMENT ......................................................................................................................... 17 FIGURE 3: VOLTAGE RIPPLE DURING TRANSMITTING .............................................................................. 24 FIGURE 4: REFERENCE CIRCUIT FOR THE VBAT INPUT ........................................................................... 25 FIGURE 5: REFERENCE CIRCUIT FOR POWER SUPPLY ............................................................................ 25 FIGURE 6: TURN ON THE MODULE WITH AN OPEN-COLLECTOR DRIVER .............................................. 26 FIGURE 7: TURN ON THE MODULE WITH A BUTTON .................................................................................. 27 FIGURE 8: TURN-ON TIMING .......................................................................................................................... 27 FIGURE 9: TURN-OFF TIMING ........................................................................................................................ 28 FIGURE 10: AN OPEN-COLLECTOR DRIVER FOR EMERG_OFF ................................................................ 30 FIGURE 11: REFERENCE CIRCUIT FOR EMERG_OFF BY USING BUTTON .............................................. 31 FIGURE 12: TIMING OF RESTARTING SYSTEM ............................................................................................ 31 FIGURE 13: TIMING OF RESTARTING SYSTEM AFTER EMERGENCY SHUTDOWN ................................ 32 FIGURE 14: VRTC IS SUPPLIED BY A NON-CHARGEABLE BATTERY ........................................................ 35 FIGURE 15: VRTC IS SUPPLIED BY A RECHARGEABLE BATTERY ............................................................ 35 FIGURE 16: VRTC IS SUPPLIED BY A CAPACITOR ...................................................................................... 36 FIGURE 17: REFERENCE DESIGN FOR FULL-FUNCTION UART ................................................................ 39 FIGURE 18: REFERENCE DESIGN FOR UART PORT ................................................................................... 40 FIGURE 19: REFERENCE DESIGN FOR UART PORT WITH HARDWARE FLOW CONTROL .................... 40 FIGURE 20: REFERENCE DESIGN FOR FIRMWARE UPGRADE ................................................................. 41 FIGURE 21: REFERENCE DESIGN FOR DEBUG PORT ............................................................................... 41 FIGURE 22: REFERENCE DESIGN FOR AUXILIARY UART PORT ............................................................... 42 FIGURE 23: LEVEL MATCH DESIGN FOR 3.3V SYSTEM .............................................................................. 42 FIGURE 24: SKETCH MAP FOR RS-232 INTERFACE MATCH ...................................................................... 43 FIGURE 25: REFERENCE DESIGN FOR AIN1&AIN2 ..................................................................................... 46 FIGURE 26: HANDSET INTERFACE DESIGN FOR AOUT1 ........................................................................... 46 FIGURE 27: SPEAKER INTERFACE DESIGN WITH AN AMPLIFIER FOR AOUT1 ....................................... 47 FIGURE 28: HANDSET INTERFACE DESIGN FOR AOUT2 ........................................................................... 47 FIGURE 29: SPEAKER INTERFACE DESIGN WITH AN AMPLIFIER FOR AOUT2 ....................................... 48 FIGURE 30: EARPHONE INTERFACE DESIGN .............................................................................................. 48 FIGURE 31: LOUD SPEAKER INTERFACE DESIGN ...................................................................................... 49 FIGURE 32: REFERENCE CIRCUIT FOR SIM1 INTERFACE WITH 8-PIN SIM CARD HOLDER ................. 51 FIGURE 33: REFERENCE CIRCUIT FOR SIM1 INTERFACE WITH THE 6-PIN SIM CARD HOLDER ......... 52 FIGURE 34: REFERENCE CIRCUIT FOR SIM2 INTERFACE WITH THE 6-PIN SIM CARD HOLDER ......... 52 FIGURE 35: REFERENCE CIRCUIT FOR SD CARD ...................................................................................... 54 FIGURE 36: LONG SYNCHRONIZATION & SIGN EXTENSION DIAGRAM ................................................... 57 FIGURE 37: LONG SYNCHRONIZATION & ZERO PADDING DIAGRAM....................................................... 57 FIGURE 38: SHORT SYNCHRONIZATION & SIGN EXTENSION DIAGRAM ................................................. 57 FIGURE 39: SHORT SYNCHRONIZATION & ZERO PADDING DIAGRAM .................................................... 58 FIGURE 40: REFERENCE DESIGN FOR PCM ............................................................................................... 58 FIGURE 41: RI BEHAVIOR OF VOICE CALLING AS A RECEIVER ................................................................ 61 FIGURE 42: RI BEHAVIOR AS A CALLER ....................................................................................................... 61
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 8 / 88 FIGURE 43: RI BEHAVIOR OF URC OR SMS RECEIVED ............................................................................. 61 FIGURE 44: REFERENCE DESIGN FOR NETLIGHT ..................................................................................... 62 FIGURE 45: REFERENCE DESIGN FOR STATUS .......................................................................................... 63 FIGURE 46: REFERENCE DESIGN FOR RF .................................................................................................. 64 FIGURE 47: RF SOLDERING SAMPLE ........................................................................................................... 67 FIGURE 48: M85 MODULE TOP AND SIDE DIMENSIONS (UNIT: MM) ......................................................... 74 FIGURE 49: M85 MODULE BOTTOM DIMENSIONS (UNIT: MM) ................................................................... 75 FIGURE 50: THE PAD DIMENSIONS (UNIT: MM) ........................................................................................... 75 FIGURE 51: RECOMMENDED FOOTPRINT (UNIT: MM) ................................................................................ 76 FIGURE 52: TOP VIEW OF THE MODULE ...................................................................................................... 77 FIGURE 53: BOTTOM VIEW OF THE MODULE .............................................................................................. 77 FIGURE 54: RAMP-SOAK-SPIKE REFLOW PROFILE .................................................................................... 79 FIGURE 55: TAPE AND REEL INFORMATION ................................................................................................ 81 FIGURE 56: RADIO BLOCK STRUCTURE OF CS-1, CS-2 AND CS-3 ........................................................... 87 FIGURE 57: RADIO BLOCK STRUCTURE OF CS-4 ....................................................................................... 88
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 9 / 88 1 Introduction This document defines the M85 module and describes its hardware interface which are connected with the customer application and the air interface. This document can help you quickly understand module interface specifications, electrical and mechanical details. Associated with application notes and user guide, you can use M85 module to design and set up mobile applications easily.
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 10 / 88 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 M85 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. Full attention must be given to driving at all times in order to reduce the risk of an accident. Using a mobie while driving (even with a handsfree kit) cause distraction and can lead to an accident. You must comply with laws and regulations restrcting the use of wireless devices while driving. 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. Consult the airline staff about the use of wireless devices on boarding the aircraft. If your device offers a Flight Mode which must be enabled prior to boarding an aircraft. Switch off your wireless device when in hospitals or clinics or other health care facilities. These requests are desinged to prevent possible interference with sentitive medical equipment. 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. 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 potencially explosive atmospheres, obey all posted signs to turn off wireless devices such as your phone or other cellular terminals. Areas with potencially exposive atmospheres including 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.
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 11 / 88 2 Product Concept 2.1. General Description M85 is a Quad-band GSM/GPRS engine that works at frequencies of GSM850MHz, EGSM900MHz, DCS1800MHz and PCS1900MHz. The M85 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 the Appendix B & C. With a tiny profile of 24.5mm × 25.3mm × 2.6mm, the module can meet almost all the requirements for M2M applications, including Vehicles and Personal Tracking, Security System, Wireless POS, Industrial PDA, Smart Metering, and Remote Maintenance & Control, etc. M85 is an SMD type module with LCC package, which can be easily embedded into applications. It provides abundant hardware interfaces like PCM and SD Card Interface. Designed with power saving technique, the current consumption of M85 is as low as 1.3 mA in SLEEP mode when DRX is 5. M85 is integrated with Internet service protocols, such as TCP/UDP, FTP and PPP. Extended AT commands have been developed for you to use these Internet service protocols easily. The module fully complies with the RoHS directive of the European Union. 2.2. Directives and Standards The M85 module is designed to comply with the FCC statements. FCC ID: XMR201511M85 The Host system using M85 should have label ―contains FCC ID: XMR201511M85‖. 2.2.1. FCC Statement Changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 12 / 88 2.2.2. FCC Radiation Exposure Statement This equipment complies with FCC 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 Mobile status of this module usage. This module should NOT be installed and operating simultaneously with other radio. The manual of the host system, which uses M85, must include RF exposure warning statement to advice user should keep minimum 20cm from the radio antenna of M85 module depending on the Mobile status. Note: If a portable device (such as PDA) uses M85 module, the device needs to do permissive change and SAR testing. The following list indicates the performance of antenna gain in certificate testing. 2.3. Key Features The following table describes the detailed features of M85 module. Table 1: Module Key Features Feature Implementation Power Supply Single supply voltage: 3.3V~4.6V Typical supply voltage: 4.0V Power Saving Typical power consumption in SLEEP mode: 1.3 mA@ DRX=5 1.2 mA@ DRX=9 Frequency Bands  Quad-band: GSM850, EGSM900, DCS1800, PCS1900  The module can search these frequency bands automatically  The frequency bands can be set by AT command  Compliant to GSM Phase 2/2+ GSM Class Small MS Transmitting Power  Class 4 (2W) at GSM850 and EGSM900  Class 1 (1W) at DCS1800 and PCS1900 Part Number Frequency Range (MHz) Peak Gain (XZ-V) Average Gain(XZ-V) VS WR Impedance GSM850:824～894MHz 3R007 EGSM900:880～960MHz DCS1800:1710～1880MHz 1 dBi typ. 1 dBi typ. 2 max 50Ω PCS1900: 1850～1990MHz
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 13 / 88 GPRS Connectivity  GPRS multi-slot class 12 (default)  GPRS multi-slot class 1~12 (configurable)  GPRS mobile station class B DATA GPRS  GPRS data downlink transfer: max. 85.6kbps  GPRS data uplink transfer: max. 85.6kbps  Coding scheme: 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/PPP/HTTP/NTP/MMS/SMTP/PING  Support Packet Broadcast Control Channel (PBCCH)  Support Unstructured Supplementary Service Data (USSD) 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 SMS  Text and PDU mode  SMS storage: SIM card SIM Interfaces 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 Suppression  Noise Reduction  Embedded one amplifier of class AB with maximum driving power up to 870mW UART Interfaces UART Port:  Seven lines on UART port interface  Used for AT command, GPRS data  Multiplexing function  Support autobauding from 4800bps to 115200bps Debug Port:  Two lines on debug port interface DBG_TXD and DBG_RXD  Use for software debugging and log output Auxiliary Port:  Used for AT command Phonebook Management Support phonebook types: SM, ME, ON, MC, RC, DC, LD, LA SIM Application Toolkit Support SAT class 3, GSM 11.14 Release 99 Real Time Clock Supported
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 14 / 88 1) When the module works within this temperature range, the deviations from the GSM specification may occur. For example, the frequency error or the phase error will be increased. Table 2: Coding Schemes and Maximum Net Data Rates over Air Interface 2.4. Functional Diagram The following figure shows a block diagram of M85 and illustrates the major functional parts.  Radio frequency part  Serial Flash  Power management  The Peripheral interface —Power supply —Turn-on/off interface —UART interfaces —Audio interfaces —SIM interfaces —SD interface —PCM interface —ADC interface —RTC interface Physical Characteristics Size: 25.3±0.15 × 24.5±0.15 × 2.6±0.2mm Weight: Approx. 3.3g Firmware Upgrade Firmware upgrade via UART Port Antenna Interface Connected to antenna pad with 50 Ohm impedance control 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 NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 15 / 88 —RF interface BB&RFRF PAM26MHzRF TransceiverRTCGPIO&PWMSerial InterfaceSIM InterfaceRF_ANTVBATPWRKEYEMERG_OFFVRTCGPIO&Status&NetlightUARTSIM Interfaces ResetESDPMUMEMORY Audio AudioPCM Interface PCM Serial FlashSD InterfaceSDADC ADC Figure 1: Module Functional Diagram 2.5. Evaluation Board In order to help customer to develop applications with M85, 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].
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 16 / 88 3 Application Interface The module adopts LCC package and has 83 pins. The following chapters provide detailed descriptions about these pins below.  Power supply  Power on/down  Power saving  RTC  Serial interfaces  Audio interfaces  SIM interfaces  SD interface  PCM interface  ADC  RI  NETLIGHT  Status
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 17 / 88 3.1. Pin of Module 3.1.1. Pin Assignment Power SIM1 RESERVED PCMOtherSDRESERVEDNETLIGHTLOUDSPKNLOUDSPKPPWRKEYEMERG_OFFPCM_INPCM_CLK RESERVEDRESERVEDRESERVED SIM_GND SIM1_RST SIM1_DATASIM1_CLKSIM1_VDDRESERVEDSIM2_VDDSIM2_CLK SIM2_DATA SIM2_RST SIM1_PRESENCEGND Audio ADC1234567891011121314151617181920 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 3738394041424344454647484950515253545556575859606162636465666768697071727374Top viewRFSIM2VBAT UARTADC0RESERVEDSPK2PAGNDMIC2PMIC2NMIC1PMIC1NSPK1NSPK1PSTATUSPCM_OUTPCM_SYNCRESERVEDRESERVEDRESERVEDRESERVEDRESERVEDRESERVEDRESERVEDRESERVEDRESERVEDRESERVEDRESERVEDRESERVEDSD_CMDSD_CLKSD_DATA0GNDTXD_AUXRXD_AUXDBG_TXDDBG_RXDDCDRIDTRCTSTXDRXDRTSVRTCVDD_EXTGNDGNDRF_ANTGNDGNDGNDVBATVBATVBATVBAT7576777879808182RESERVEDRESERVEDRESERVEDRESERVEDGNDGNDGNDGNDRESERVED83 Figure 2: Pin Assignment Keep all reserved pins open. NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 18 / 88 3.1.2. Pin Description Table 3: Pin Description Power Supply PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT VBAT 67, 68, 69, 70 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 typically rises to 1.6A. VRTC 59 I/O Power supply for RTC. Charging for backup battery or golden capacitor when the VBAT is applied. VImax=3.3V VImin=1.5V VInorm=2.8V VOmax=3V VOmin=2V VOnorm=2.8V Iout(max)=2mA Iin≈10uA If unused, keep this pin open. VDD_EXT 60 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. Recommend to add a 2.2~4.7uF bypass capacitor, when using this pin for power supply. GND 37, 61, 62, 64~66, 79~82, Ground Turn on/off PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT PWRKEY 15 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 VIHmax=3.1V Emergency Shutdown
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 19 / 88 PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT EMERG_ OFF 17 I Emergency off. Pulled down for at least 40ms, which will turn off the module in case of emergency. Use it only when shutdown via PWRKEY or AT command cannot be achieved. VILmax=0.45V VIHmin=1.35V Vopenmax=1.8V 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 16 O Indicate module’s operating status. Output high level when module turns on, while output low level when module turns off. 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 9, 10 I Channel 1 positive and negative voice input Refer to Section 3.8 If unused, keep these pins open. MIC2P MIC2N 7, 8 I Channel 2 positive and negative voice input SPK1P SPK1N 12, 11 O Channel 1 positive and negative voice output 1. If unused, keep these pins open. 2. Support both voice and ringtone output. SPK2P 5 O Channel 2 voice output AGND 6 Analog ground. Separate ground connection for external audio circuits. If unused, keep this pin open. LOUDSPKN LOUDSPKP 13, 14 O Channel 3 positive and negative voice output 1. If unused, keep these pins open. 2. Integrate a Class- AB amplifier internally. 3. Support both voice and
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 20 / 88 ringtone output. Network Status Indicator PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT NETLIGHT 4 O Network status indication VOHmin= 0.85×VDD_EXT VOLmax= 0.15×VDD_EXT If unused, keep this pin open. UART Port PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT DTR 47 I Data terminal ready VILmin=0V VILmax= 0.25×VDD_EXT VIHmin= 0.75×VDD_EXT VIHmax= VDD_EXT+0.2 VOHmin= 0.85×VDD_EXT VOLmax= 0.15×VDD_EXT If only use TXD, RXD and GND to communicate, recommended connecting RTS to GND via 0R resistor and keeping other pins open. RXD 50 I Receive data TXD 49 O Transmit data RTS 51 I Request to send CTS 48 O Clear to send RI 46 O Ring indication DCD 45 O Data carrier detection Debug Port PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT DBG_TXD 42 O Transmit data Same as above If unused, keep these pins open. DBG_RXD 43 I Receive data Auxiliary Port PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT TXD_AUX 40 O Transmit data Same as above If unused, keep these pins open. RXD_AUX 41 I Receive data SIM Interface PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 21 / 88 SIM1_VDD 56 O Power supply for SIM card The voltage can be selected by software automatically. Either 1.8V or 3V. All signals of SIM interface should be protected against ESD with a TVS diode array. Maximum trace length is 200mm from the module pad to SIM card holder. SIM2_VDD 71 SIM1_CLK 55 O SIM clock VOLmax= 0.15×SIM_VDD VOHmin= 0.85×SIM_VDD SIM2_CLK 72 SIM1_ DATA 54 I/O SIM data VILmax= 0.25×SIM_VDD VIHmin= 0.75×SIM_VDD VOLmax= 0.15×SIM_VDD VOHmin= 0.85×SIM_VDD SIM2_DATA 73 SIM1_RST 53 O SIM reset VOLmax= 0.15×SIM_VDD VOHmin= 0.85×SIM_VDD SIM2_RST 74 SIM1_ PRESENCE 57 I SIM card detection VILmin=0V VILmax= 0.25×VDD_EXT VIHmin= 0.75×VDD_EXT VIHmax= VDD_EXT+0.2 If unused, keep these pins open. SIM_GND 52 SIM ground ADC PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT ADC0 2 I General purpose analog to digital converter. Voltage range: 0V to 2.8V If unused, keep this pin open. PCM PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT PCM_CLK 19 O PCM clock VILmin= 0V VILmax= 0.25×VDD_EXT If unused, keep these pins open. PCM_IN 18 I PCM data input
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 22 / 88 PCM_OUT 20 O PCM data output VIHmin= 0.75×VDD_EXT VIHmax= VDD_EXT+0.2 VOHmin= 0.85×VDD_EXT VOLmax= 0.15×VDD_EXT If unused, keep these pins open. PCM_SYNC 21 O PCM frame synchronization SD Card PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT SD_CMD 34 O SD command VILmin=0V VILmax= 0.25×VDD_EXT VIHmin= 0.75×VDD_EXT VIHmax= VDD_EXT+0.2 VOHmin= 0.85×VDD_EXT VOLmax= 0.15×VDD_EXT If unused, keep these pins open. SD_CLK 35 O SD clock SD_DATA0 36 I/O SD data Antenna Interface PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT RF_ANT 63 I/O RF antenna pad Impedance of 50Ω Other Interface PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT RESERVD 1, 3, 22~33, 38, 39, 44, 58, 75~78, 83 Keep these pins open.
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 23 / 88 3.2. Operating Modes The table below briefly summarizes the various operating modes in the following chapters. Table 4: Overview of Operating Modes Mode Function Normal Operation GSM/GPRS Sleep After enabling sleep mode by AT+QSCLK=1, 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 ongoing. 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 or 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.
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 24 / 88 Use the EMERG_OFF pin only when failing to turn off the module by the command AT+QPOWD=1 and the PWRKEY pin. For more details, please refer to the Section 3.4.2.4. 3.3. Power Supply 3.3.1. Power Features of Module The power supply is one of the key issues in designing GSM terminals. Because of the 577us radio burst in GSM every 4.615ms, power supply must be able to deliver high current peaks in a burst period. During these peaks, drops on the supply voltage must not exceed minimum working voltage of module. For the M85 module, the max current consumption could reach to 1.6A during a transmit burst. It will cause a large voltage drop on the VBAT. In order to ensure stable operation of the module, it is recommended that the max voltage drop during the transmit burst does not exceed 400mV. Vdrop4.615ms577usIBATVBATBurst:1.6A Figure 3: Voltage Ripple during Transmitting 3.3.2. Decrease Supply Voltage Drop The power supply range of the module is 3.3V to 4.6V. Make sure that the input voltage will never drop below 3.3V even in a transmitting burst. If the power voltage drops below 3.3V, the module could turn off automatically. For better power performance, it is recommended to place a 100uF tantalum capacitor with low ESR (ESR=0.7Ω) and ceramic capacitor 100nF, 33pF and 10pF near the VBAT pin. The reference circuit is illustrated in Figure 4. The VBAT route should be wide enough to ensure that there is not too much voltage drop during transmit burst. The width of trace should be no less than 2mm and the principle of the VBAT route is the longer route, the wider trace. NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 25 / 88 VBATC2C1+C3 C4GND100uF 100nF 10pF060333pF0603 Figure 4: Reference Circuit for the VBAT Input 3.3.3. Reference Design For Power Supply The power design for the module is very important, since the performance of power supply for the module largely depends on the power source. The power supply is capable of providing the sufficient current up to 2A at least. If the voltage drop between the input and output is not too high, it is suggested to use a LDO as module’s power supply. If there is a big voltage difference between the input source and the desired output (VBAT), a switcher power converter is recommended to use as a power supply. Figure 5 shows a reference design for +5V input power source. The designed output for the power supply is 4.0V and the maximum load current is 3A. In addition, in order to get a stable output voltage, a zener diode is placed close to the pins of VBAT. As to the zener diode, it is suggested to use a zener diode whose reverse zener voltage is 5.1V and dissipation power is more than 1 Watt. DC_INC1 C2MIC29302WU U1IN OUTENGNDADJ2 4135VBAT 100nFC3470uFC4100nFR2D1124K56KR3470uF 5.1VR4470RMCU_POWER_ON/OFF47K4.7KR5R6R151K Figure 5: Reference Circuit for Power Supply
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 26 / 88 It is suggested to control the module’s main power supply (VBAT) via LDO enable pin to restart the module when the module has become abnormal. Power switch circuit like P-channel MOSFET switch circuit can also be used to control VBAT. 3.3.4. Monitor Power Supply The command AT+CBC can be used to monitor the supply voltage of the module. The unit of the displayed voltage is mV. For details, please refer to the document [1]. 3.4. Power On and Down Scenarios 3.4.1. Power On The module can be turned on by driving the pin PWRKEY to a low level voltage. An open collector driver circuit is suggested to control the PWRKEY. A simple reference circuit is illustrated as below. Turn on pulsePWRKEY4.7K47K Figure 6: Turn on the Module with an Open-collector Driver 1. M85 module is set to autobauding mode (AT+IPR=0) by default. In the autobauding mode, URC ―RDY‖ is not reported to the host controller after module is powered on. When the module is powered on after a delay of 4 or 5 seconds, it can receive AT command. Host controller should first send an AT string in order that the module can detect baud rate of host controller, and it should continue to send the next AT string until receiving OK string from the module. Then enter AT+IPR=x;&W to set a fixed baud rate for the module and save the configuration to flash memory of the module. After these NOTES NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 27 / 88 configurations, the URC RDY would be received from the UART Port of the module every time when the module is powered on. For more details, refer to the section AT+IPR in document [1]. 2. AT command response indicates module is turned on successfully, or else the module fails to be turned on. The other way to control the PWRKEY is through a button directly. A TVS component is indispensable to be placed nearby the button for ESD protection. For the best performance, the TVS component must be placed nearby the button. When pressing the key, electrostatic strike may generate from finger. A reference circuit is shown in the following figure. PWRKEYK1Close to K1TVS Figure 7: Turn on the Module with a Button The turn-on timing is illustrated as the following figure. VDD_EXT(OUTPUT)VIL<0.1*VBATVIH > 0.6*VBATVBATPWRKEY(INPUT)EMERG_OFF(INPUT)54msSTATUS(OUTPUT)800ms>1sOFF BOOTINGMODULE STATUS RUNNINGT1 Figure 8: Turn-on Timing
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 28 / 88 1. Make sure that VBAT is stable before pulling down PWRKEY pin. The time of T1 is recommended as 100ms. 2. EMERG_OFF should be floated when it is unused. 3. For more details about the application of STATUS pin, please refer to the Chapter 3.15. 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. 3.4.2.1. Power Down Module Using the PWRKEY Pin It is a safe way to turn off the module by driving the PWRKEY to a low level voltage for a certain time. The power down scenario is illustrated as the following figure. VBATPWRKEY(INPUT)STATUS(OUTPUT)EMERG_OFF(INPUT)Logout net about 2s to 12s0.7s<Pulldown<1s Figure 9: Turn-off timing The power down procedure causes the module to log off from the network and allows the firmware to save important data before completely disconnecting the power supply. NOTES
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 29 / 88 Before the completion of the power down procedure, module sends out the result code shown as below: NORMAL POWER DOWN 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. 1. This unsolicited result codes do not 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. 2. As logout network time is related to the local mobile network, it is recommended to delay about 12 seconds before disconnecting the power supply or restarting the module. 3. For more details about the application of STATUS pin, please refer to the Chapter 3.15. 3.4.2.2. Power Down Module Using AT Command It is also a safe way to 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 firmware to save important data before completely disconnecting the power supply. Before the completion of the power down procedure, 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. Please refer to the 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 NOTES
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 30 / 88 The normal input voltage range is from 3.3V to 4.6V. If the voltage is >4.6V or <3.3V, the module would automatically shut down 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 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. 1. These unsolicited result codes do not 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. 2. Over-voltage warning and shutdown function is disabled by default. 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 40ms 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: An Open-collector Driver for EMERG_OFF NOTES
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 31 / 88 K2EMERG_OFFTVS2Close to K2 Figure 11: Reference Circuit for EMERG_OFF by Using Button 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 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. 3.4.3. Restart The module can be restarted by driving the PWRKEY to a low level voltage for a certain time, which is similar to the way of turning on module. In order to make the internal LDOs discharge completely after turning off the module, it is recommended to delay about 500ms before restarting the module. The restart timing is illustrated as the following figure. PWRKEY(INPUT)STATUS(OUTPUT)Delay >500msTurn off RestartPull down the PWRKEY to turn on the module Figure 12: Timing of Restarting System
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 32 / 88 The module can also be restarted by the PWRKEY after emergency shutdown. EMERG_OFF(INPUT)STATUS(OUTPUT)Delay >500msPulldown >40msPWRKEY(INPUT) Figure 13: Timing of Restarting System after Emergency Shutdown For more details about the application of STATUS pin, please refer to the Chapter 3.15. 3.5. Power Saving Based on system requirements, 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 a minimum level. The consumption of the current can be minimized when the slow clocking mode is activated at the same time. The 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 related with RF function or SIM card function will be not available. NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 33 / 88 If the module has been set by the command with AT+CFUN=4, the RF function will be disabled, but the UART port is still active. In this case, all AT commands related with RF function will be not available. 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 the document [1]. 3.5.2. SLEEP Mode The SLEEP mode is disabled by default. You can enable it 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 the module is set by the command with AT+QSCLK=1, you 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 does not work. 3.5.3. Wake up 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.  Receive a voice or GPRS data from network wakes up module.  Receive an SMS from network wakes up module. DTR pin should be held at low level during communication between the module and DTE. 3.5.4. Summary of State Transition Table 5: Summary of State Transition Current Mode Next Mode Power Down Normal Mode Sleep Mode Power Down Use PWRKEY NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 34 / 88 3.6. RTC Backup The RTC (Real Time Clock) function is supported. The RTC is designed to work with an internal power supply. There are three kinds of designs for RTC backup power:  Use VBAT as the RTC power source When the module is turned off and the main power supply (VBAT) is remained, the real time clock is still active as the RTC core is supplied by VBAT. In this case, the VRTC pin can be kept floating.  Use VRTC as the RTC power source If the main power supply (VBAT) is removed after the module is turned off, a backup supply such as a coin-cell battery (rechargeable or non-chargeable) or a super-cap can be used to supply the VRTC pin to keep the real time clock active.  Use VBAT and VRTC as the RTC power source As only power the VRTC pin to keep the RTC will lead an error about 5 minutes a day, it is recommended to power VBAT and VRTC pin at the same time when RTC function is needed. The recommended supply for RTC core circuits are shown as below. Normal Mode AT+QPOWD, use PWRKEY pin, or use EMERG_OFF pin Use AT command AT+QSCLK=1 and pull up DTR SLEEP Mode Use PWRKEY pin, or use EMERG_OFF pin Pull DTR down or incoming voice call or SMS or GPRS data transmission
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 35 / 88 Non-chargeable Backup BatteryModuleRTC CoreVBATPower SupplyLDO/DCDC LDOVRTC 1.5K Figure 14: VRTC is Supplied by a Non-chargeable Battery Rechargeable Backup BatteryModuleRTC CoreVBATPower SupplyLDO/DCDC LDOVRTC 1.5K Figure 15: VRTC is Supplied by a Rechargeable Battery
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 36 / 88 ModuleRTC CoreVBATPower SupplyLDO/DCDC LDOVRTC 1.5KLarge Capacitance Capacitor Figure 16: VRTC is Supplied by a Capacitor For the choice of a rechargeable or non-chargeable coin-cell battery, please visit http://www.sii.co.jp/en/. If you want to keep an accurate real time, please keep the main power supply VBAT alive. 3.7. Serial Interfaces The module provides three serial ports: UART Port, Debug Port and Auxiliary 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: Request to send.  CTS: Clear to send.  DTR: DTE is ready and inform DCE (this pin can wake the module up).  RI: Ring indicator (when there is a call, SMS or URC output, the module will inform DTE with the RI pin).  DCD: Data carrier detection (the validity of this pin demonstrates the communication link is set up). NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 37 / 88 Hardware flow control is disabled by 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 the document [1]. The Debug Port:  DBG_TXD: Send data to the COM port of computer.  DBG_RXD: Receive data from the COM port of computer. The Auxiliary UART Port:  TXD_AUX: Send data to the RXD of DTE.  RXD_AUX: Receive data from the TXD of DTE. The logic levels are described in the following table. Table 6: Logic Levels of the UART Interface Table 7: Pin Definition of the UART Interfaces Parameter Min. Max. Unit VIL 0 0.25×VDD_EXT V VIH 0.75×VDD_EXT VDD_EXT +0.2 V VOL 0 0.15×VDD_EXT V VOH 0.85×VDD_EXT VDD_EXT V Interface Pin Name Pin No. Description Debug Port DBG_RXD 43 Receive data DBG_TXD 42 Transmit data UART Port DCD 45 Data carrier detection RI 46 Ring indication NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 38 / 88 3.7.1. UART Port 3.7.1.1. The Features of UART Port  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, 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 and 115200.  The default setting is autobauding mode. Support the following baud rates for autobauding function: 4800, 9600, 19200, 38400, 57600 and 115200.  The module disables hardware flow control by 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. Autobauding allows the module to detect the baud rate by receiving the string 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 by default. To take advantage of the autobauding mode, special attention should be paid according to the following requirements: 1. Synchronization between DTE and DCE When DCE (the module) powers on with the autobauding enabled, it is recommended to wait 4 or 5 seconds before sending the first AT character. After receiving the OK response, DTE and DCE are correctly synchronized. DTR 47 Data terminal ready CTS 48 Clear to send TXD 49 Transmit data RXD 50 Receive data RTS 51 Request to send Auxiliary UART Port TXD_AUX 40 Transmit data RXD_AUX 41 Receive data
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 39 / 88 If the host controller needs URC in the mode of autobauding, it must be synchronized firstly. Otherwise the URC will be discarded. 2. Restrictions on autobauding operation  The UART port has to be operated at 8 data bits, no parity and 1 stop bit (factory setting).  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 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. 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 the Section AT+IPR in document [1]. 3.7.1.2. The Connection of UART Port The connection between module and host using UART Port is very flexible. Three connection styles are illustrated as below. Reference design for Full-Function UART connection is shown as below when it is applied in modulation-demodulation. TXDRXDRTSCTSDTRDCDRITXDRXDRTSCTSDTRDCDRINGModule (DCE)Serial portUART portGND GNDPC (DTE) Figure 17: Reference Design for Full-Function UART NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 40 / 88 Three-line connection is shown as below. TXDRXDGNDUART portRTS 0RTXDRXDGNDModule (DCE) Host (DTE)Controller Figure 18: Reference Design for UART Port UART Port with hardware flow control is shown as below. This connection will enhance the reliability of the mass data communication. RTSCTSRTSCTSGNDRXDTXD TXDRXDGNDModule (DCE) Host (DTE) Controller Figure 19: Reference Design for UART Port with Hardware Flow Control 3.7.1.3. Firmware Upgrade The TXD, RXD can be used to upgrade firmware. The PWRKEY pin must be pulled down before firmware upgrade. The reference circuit is shown as below:
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 41 / 88 IO Connector TXDRXDGNDPWRKEY Module (DCE) UART portTXDRXDGNDPWRKEY Figure 20: Reference Design for Firmware Upgrade The firmware of module might need to be upgraded due to certain reasons. It is recommended to reserve these pins in the host board for firmware upgrade. 3.7.2. Debug Port  Two lines: DBG_TXD and DBG_RXD  It outputs log information automatically.  Debug Port is only used for firmware debugging and its baud rate must be configured as 460800bps. The reference design for Debug Port is shown as below. PeripheralTXDRXDGND Module DBG_TXDDBG_RXD GND Figure 21: Reference Design for Debug Port NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 42 / 88 3.7.3. Auxiliary UART Port  Two data lines: TXD_AUX and RXD_AUX.  Auxiliary UART port is used for AT command only and does not support GPRS data, multiplexing function etc.  Auxiliary UART port supports the communication baud rates as the following: 1200, 2400, 4800, 9600, 14400, 19200, 28800, 38400, 57600, 115200bps.  Auxiliary UART port could be used when you send AT+QEAUART=1 string on the UART port.  The default baud rate setting is 115200bps, and does not support autobauding. The baud rate can be modified by AT+QSEDCB command. For more details, please refer to the document [1]. PeripheralTXDRXDGND Module TXD_AUXRXD_AUX GND Figure 22: Reference Design for Auxiliary UART Port 3.7.4. UART Application The reference design of 3.3V level match is shown as below. If the host is a 3V system, please change the 5.6K resistor to 10K. Peripheral/TXD/RXD1KTXDRXDRTSCTSDTRRI/RTS/CTSGPIOEINTGPIO DCDModule1K1KVoltage level:3.3V5.6K5.6K5.6K1K1K1K1KGND GND Figure 23: Level Match Design for 3.3V System
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 43 / 88 It is highly recommended to add the resistor divider circuit on the UART signal lines when the host’s level is 3V or 3.3V. For the higher voltage level system, a level shifter IC could be used between the host and the module. For more details about UART circuit design, please refer to document [11]. The following figure shows a sketch map between module and standard RS-232 interface. Since the electrical level of module is 2.8V, so a RS-232 level shifter must be used. Note that you should assure the IO voltage of level shifter which connects to module is 2.8V. TXDRXDRTSCTSDTRRIDCDModuleGNDC1+C1-C2+C2-V+VCCGNDV-3.3VT1INT2INT3INT4INR1INR2INR3INR1OUTR2OUTR3OUTT1OUTT2OUTT5OUTT3OUTT4OUTT5INGNDGND/R1OUT123456789GNDTo PC Serial PortGND1K1K1K1K1K5.6K5.6K1K1K5.6KRS-232 Level Shifter Figure 24: Sketch Map for RS-232 Interface Match Please visit vendor website to select the suitable RS-232 level shifter IC, such as: http://www.exar.com/ and http://www.maximintegrated.com. NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 44 / 88 3.8. Audio Interfaces The module provides two analogy input channels and three analogy output channels. Table 8: 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. This channel is typically used for a receiver built into a handset. AOUT1 channel is a differential channel. AOUT2 is typically used with earphone. It is a single-ended and mono channel. SPK2P and AGND can establish a pseudo differential mode. AOUT2 can also be used for output of receiver, which can be used as a single-ended channel. SPK2P and AGND can establish a pseudo differential mode. AOUT3 is used for loud speaker output as it embedded an amplifier of class AB whose maximum drive power is 870mW. All of these three audio channels support voice and ringtone output, and so on, and can be switched by AT+QAUDCH command. For more details, please refer to the document [1]. Interface Pin Name Pin No. Description AIN1/AOUT1 MIC1P 9 Channel 1 Microphone positive input MIC1N 10 Channel 1 Microphone negative input SPK1P 12 Channel 1 Audio positive output SPK1N 11 Channel 1 Audio negative output AIN2/AOUT2 MIC2P 7 Channel 2 Microphone positive input MIC2N 8 Channel 2 Microphone negative input SPK2P 5 Channel 2 Audio positive output AGND 6 Form a pseudo-differential pair with SPK2P AOUT3 LOUDSPKP 14 Channel 3 Audio positive output LOUDSPKN 13 Channel 3 Audio negative output
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 45 / 88 Use AT command AT+QAUDCH to select audio channel:  0--AIN1/AOUT1, the default value is 0.  1--AIN2/AOUT2  2--AIN2/AOUT3 For each channel, you 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+QSIDET is used to set the side-tone gain level. For more details, please refer to the document [1]. Table 9: AOUT3 Output Characteristics 3.8.1. Decrease TDD Noise and Other Noise The 33pF capacitor is applied for filtering out 900MHz RF interference when the module is transmitting at EGSM900MHz. 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, you would have to discuss with its capacitor vendor to choose the most suitable capacitor for filtering out GSM850MHz, EGSM900MHz, 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, you 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 audio interface. 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. Item Condition Min. Type Max. Unit RMS Power 8ohm load VBAT=4.2V THD+N=1% 870 mW 8ohm load VBAT=3.3V THD+N=1% 530 mW
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 46 / 88 3.8.2. Microphone Interfaces Design AIN1 and AIN2 channels come with internal bias supply for external electret microphone. A reference circuit is shown in the following figure. MICxPDifferential layoutModule 10pF 33pF33pF33pFGNDGNDElectret MicrophoneGNDGND10pF10pFGNDGNDESDESDMICxNClose to Microphone060306030603060306030603 Figure 25: Reference Design for AIN1&AIN2 3.8.3. Receiver and Speaker Interface Design SPK1PSPK1NDifferential layoutModule10pF 0603Close to speakerGNDESD 33pF 060333pF 0603GND10pF 0603 ESD 10pF 060333pF 0603 Figure 26: Handset Interface Design for AOUT1
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 47 / 88 SPK1PSPK1NDifferential layout AmplifiercircuitModule10pF 0603Close to speakerGNDESD 33pF 060333pF 0603GND10pF 0603 ESD 10pF 060333pF 0603 Figure 27: Speaker Interface Design with an Amplifier for AOUT1 SPK2PAGNDDifferential layout 10pF0603 33pF0603Close to SpeakerGNDESD Module22uF Figure 28: Handset Interface Design for AOUT2
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 48 / 88 ModuleSPK2PAGNDDifferential layout Amplifiercircuit10pF060310pF060333pF060333pF0603Close to SpeakerGNDGNDESD ESD C2C1 Figure 29: Speaker Interface Design with an Amplifier for AOUT2 The suitable differential audio amplifier can be chosen from the Texas Instrument’s website (http://www.ti.com/). There are other excellent audio amplifier vendors in the market too. 4. The value of C1 and C2 here depends on the input impedance of audio amplifier. 3.8.4. Earphone Interface Design 1243SPK2PMIC2NMIC2P22uF68RAGNDClose to SocketDifferential layoutAGNDAGNDModule4.7uFESD GND33pF 060310pF 060333pF 0603GND10pF 0603ESD Figure 30: Earphone Interface Design NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 49 / 88 3.8.5. Loud Speaker Interface Design LOUDSPKPLOUDSPKNDifferential layout 10pF10pF 33pF33pFClose to SpeakerGNDGND100pFESDESD Module0R0R06030603 06030603 Figure 31: Loud Speaker Interface Design 3.8.6. Audio Characteristics Table 10: Typical Electret Microphone Characteristics Table 11: Typical Speaker 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 kΩ Parameter Min. Typ. Max. Unit AOUT1 Output Single-ended Load resistance 32 Ohm Ref level 0 2.4 Vpp Differential Load resistance 32 Ohm Ref level 0 4.8 Vpp
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 50 / 88 3.9. SIM Card Interfaces The module contains two SIM interfaces to allow module access the two SIM cards. Only one SIM card can work at a time. Both of two SIM interfaces share the ground and only first SIM interface have card insert detection. In dual SIM card mode, configure AT+QDSIM=0 to use the SIM1 interface and configure AT+QDSIM=1 to use SIM2 interface. For more details, please refer to the document [1]. 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. The SIM interface is powered by an internal regulator in the module. Both 1.8V and 3.0V SIM Cards are supported. Table 12: Pin Definition of the SIM Interface AOUT2 Output Single-ended Load resistance 32 Ohm Ref level 0 2.4 Vpp AOUT3 Output Differential Load resistance 8 Ohm Ref level 0 2×VBAT Vpp Pin Name Pin No. Description SIM1_VDD 56 Supply power for SIM card. Automatic detection of SIM card voltage. 3.0V±10% and 1.8V±10%. Maximum supply current is around 10mA. SIM2_VDD 71 SIM1_CLK 55 SIM card clock SIM2_CLK 72 SIM1_DATA 54 SIM card data I/O SIM2_DATA 73 SIM1_RST 53 SIM card reset SIM2_RST 74
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 51 / 88 The following figure is the reference design for SIM interface, and here an 8-pin SIM card holder is used. The pin SIM1_PRESENCE is used to detect whether the tray of the Molex SIM socket, which is used for holding SIM card, is present in the card socket. When the tray is inserted in the socket, SIM1_PRESENCE is at low level. Regardless of the SIM card is in the tray or not, the change of SIM1_PRESENCE level from high to low level prompts the module to reinitialize SIM card. In default configuration, SIM card detection function is disabled. Your application can use AT+QSIMDET=1,0 and AT+QSIMDET=0,0 to switch on and off the SIM card detection function. For details of this AT command, please refer to document [1]. When AT+QSIMDET=1,0 is set and the tray with SIM card is removed from SIM socket, the following URC will be presented: +CPIN: NOT INSERTED When the tray with SIM card is inserted into SIM socket again and the module finishes reinitializing SIM card, the following URC will be presented: +CPIN: READY Call Ready VDD_EXTModuleSIM1_VDDSIM_GNDSIM1_RSTSIM1_CLKSIM1_DATASIM1_PRESENCE22R22R22R10K100nF SIM_HolderGNDGNDTVS33pF33pF 33pF33pFVCCRSTCLK IOVPPGNDGND Figure 32: Reference Circuit for SIM1 Interface with 8-pin SIM Card Holder SIM1_PRESENCE 57 SIM1 card detection SIM_GND 52 SIM card ground
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 52 / 88 If the SIM1 card detection function is not used, keep SIM1_PRESENCE pin open. The reference circuit for a 6-pin SIM card socket is illustrated as the following figure. ModuleSIM1_VDDSIM_GNDSIM1_RSTSIM1_CLKSIM1_DATASIM1_PRESENCE22R22R22R100nF SIM_HolderGNDTVS33pF33pF 33pFVCCRSTCLK IOVPPGNDGND33pF Figure 33: Reference Circuit for SIM1 Interface with the 6-pin SIM Card Holder The following figure is the reference design for SIM2 interface with the 6-pin SIM card holder. ModuleSIM2_VDDSIM_GNDSIM2_RSTSIM2_CLKSIM2_DATA 22R22R22R100nF SIM_HolderGNDTVS33pF33pF 33pFVCCRSTCLK IOVPPGNDGND33pF Figure 34: Reference Circuit for SIM2 Interface with the 6-pin SIM Card Holder For more information of SIM card holder, please visit http://www.amphenol.com and http://www.molex.com.
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 53 / 88 In order to enhance the reliability and availability of the SIM card in application. Please follow the below criteria in the SIM circuit design:  Keep layout of SIM card as close as possible to the module. Assure the length of the trace as less than 200mm as possible.  Keep SIM card signals away from RF and VBAT alignment.  Assure the ground between module and SIM cassette short and wide. Keep the width of ground no less than 0.5mm to maintain the same electric potential. The decouple capacitor of SIM_VDD is less than 1uF and must be near to SIM cassette.  To avoid cross talk between SIM_DATA and SIM_CLK. Keep them away with each other and shield them with surrounded ground.  In order to offer good ESD protection, it is recommended to add a TVS diode array. For more information of TVS diode, please visit http://www.onsemi.com/.The most important rule is to place the ESD protection device close to the SIM card socket and make sure the nets being protected will go through the ESD device first and then lead to module. The 22Ω resistors should be connected in series between the module and the SIM card so as to suppress the EMI spurious transmission and enhance the ESD protection. Please to be noted that the SIM peripheral circuit should be close to the SIM card socket.  Place the RF bypass capacitors (33pF) close to the SIM card on all signal lines for improving EMI. 3.10. SD Card Interface The module provides SD card interface that supports many types of memory, such as Memory Stick, SD/MCC card and T-Flash or Micro SD card. The following are the main features of SD card interface.  Only supports 1bit serial mode.  Not support the SPI mode for SD memory card.  Not support multiple SD memory cards.  Not support hot plug.  The data rate up to 48MHz in serial mode.  Up to 32GB maximum memory card capacity. With the SD card interface features and reference circuit shown as below, you can easily design the SD card application circuit to enhance the memory capacity of the module. The users can store some high-capacity files to external memory card. Such as in the automotive application system, the module can record and store the audio file to the SD card, and also can play the audio files in SD card.
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 54 / 88 Table 13: Pin Definition of the SD Card Interface ModuleSD_DATA0SD_CLKSD_CMDDATA2DATA1DATA0CD/DATA3CMDVSS1VDDCLKVSS247K47K 47K4.7uF 0.1nFVDD_EXT33R33R33RSD Socket123456789 Figure 35: Reference Circuit for SD Card Table 14: Pin Definition of the SD Card Interface Pin Name Pin No. Description SD_CMD 34 Command signal of SD card output SD_CLK 35 Clock signal of SD card output SD_DATA0 36 Data output and input signal of SD card Pin No. Pin Name of SD Card Pin Name of T-Flash (Micro SD) Card 1 CD/DATA3 DATA2 2 CMD CD/DATA3 3 VSS1 CMD 4 VDD VDD 5 CLK CLK 6 VSS2 VSS 7 DATA0 DATA0
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 55 / 88 In SD card interface designing, in order to ensure good communication performance with SD card, the following design principles should be complied with:  Keep all the SD card signals far away from VBAT power and RF trace.  Route all SD card signals as short as possible. Ensure the length of every trace does not exceed 10cm.  The SD_CLK, SD_DATA0 and SD_CMD trace should be routed together. Keep trace difference of SD_DATA0, SD_CMD and SD_CLK to be less than 10mm.  In order to offer good ESD protection, it is recommended to add TVS on signals with the capacitance less than 15pF.  Reserve external pull-up resistors for other data lines except the DATA0 signal.  The SD_CLK and SD_DATA0 line must be shielded by ground in order to improve EMI. 3.11. PCM Interface M85 supports PCM interface. It is used for digital audio transmission between the module and the device. This interface is composed of PCM_CLK, PCM_SYNC, PCM_IN and PCM_OUT signal lines. Pulse-code modulation (PCM) is a converter that changes the consecutive analog audio signal to discrete digital signal. The whole procedure of Pulse-code modulation contains sampling, quantizing and encoding. Table 15: Pin Definition of PCM Interface 8 DATA1 DATA1 9 DATA2 Pin Name Pin No. Description PCM_IN 18 PCM data input PCM_CLK 19 PCM clock output PCM_OUT 20 PCM data output PCM_SYNC 21 PCM frame synchronization output
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 56 / 88 3.11.1. Configuration M85 module supports 13-bit line code PCM format. The sample rate is 8 KHz, and the clock source is 256 KHz, and the module can only act as master mode. The PCM interface supports both long and short synchronization simultaneously. Furthermore, it only supports MSB first. For detailed information, please refer to the table below. Table 16: Configuration 3.11.2. Timing The sample rate of the PCM interface is 8 KHz and the clock source is 256 KHz, so every frame contains 32 bits data, since M85 supports 16 bits line code PCM format, the left 16 bits are invalid. The following diagram shows the timing of different combinations. The synchronization length in long synchronization format can be programmed by firmware from one bit to eight bits. In the Sign extension mode, the high three bits of 16 bits are sign extension, and in the Zero padding mode, the low three bits of 16 bits are zero padding. Under zero padding mode, you can configure the PCM input and output volume by executing AT+QPCMVOL command. For more details, please refer to Chapter 3.11.4. PCM Line Interface Format Linear Data Length Linear: 13 bits Sample Rate 8KHz PCM Clock/Synchronization Source PCM master mode: clock and synchronization is generated by module PCM Synchronization Rate 8KHz PCM Clock Rate PCM master mode: 256 KHz (line) PCM Synchronization Format Long/short synchronization PCM Data Ordering MSB first Zero Padding Yes Sign Extension Yes
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 57 / 88 12 11 10 9 8 7 6 5 4 3 2 1 012 11 10 9 8 7 6 5 4 3 2 1 0PCM_CLKPCM_SYNCPCM_OUTPCM_INMSBMSBSign extensionSign extension Figure 36: Long Synchronization & Sign Extension Diagram 12 11 10 9 8 7 6 5 4 3 2 1 012 11 10 9 8 7 6 5 4 3 2 1 0PCM_CLKPCM_SYNCPCM_OUTPCM_INMSBMSBZero paddingZero padding Figure 37: Long Synchronization & Zero Padding Diagram PCM_CLKPCM_SYNCPCM_OUTPCM_IN12 11 10 9 8 7 6 5 4 3 2 1 012 11 10 9 8 7 6 5 4 3 2 1 0MSBMSBSign extensionSign extension Figure 38: Short synchronization & Sign Extension Diagram
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 58 / 88 PCM_CLKPCM_SYNCPCM_OUTPCM_IN12 11 10 9 8 7 6 5 4 3 2 1 012 11 10 9 8 7 6 5 4 3 2 1 0MSBMSBZero paddingZero padding Figure 39: Short Synchronization & Zero Padding Diagram 3.11.3. Reference Design M85 can only work as a master, providing synchronization and clock source. The reference design is shown as below. PCM_SYNCPCM_CLKPCM_OUTPCM_INPCM_SYNCPCM_CLKPCM_INPCM_OUTModule(Master)Peripheral(Slave) Figure 40: Reference Design for PCM 3.11.4. AT Command There are two AT commands about the configuration of PCM are listed as below. AT+QPCMON can configure operating mode of PCM. AT+QPCMON= mode,Sync_Type,Sync_Length,SignExtension,MSBFirst.
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 59 / 88 Table 17: QPCMON Command Description AT+QPCMVOL can configure the volume of input and output. AT+QPCMVOL=vol_pcm_in, vol_pcm_out Table 18: QPCMVOL Command Description 3.12. ADC The module provides an ADC channel to measure the value of voltage. Please give priority to the use of ADC0 channel. The command AT+QADC can read the voltage value applied on ADC0 pin. For details of this AT command, please refer to the document [1]. In order to improve the accuracy of ADC, the layout of ADC should be surrounded by ground. Parameter Scope Description Mode 0~2 0: Close PCM 1: Open PCM 2: Open PCM when audio talk is set up Sync_Type 0~1 0: Short synchronization 1: Long synchronization Sync_Length 1~8 Programmed from one bit to eight bit SignExtension 0~1 0: Zero padding 1: Sign extension MSBFirst 0~1 0: MSB first 1: Not supported Parameter Scope Description vol_pcm_in 0~32767 Set the input volume vol_pcm_out 0~32767 Set the output volume The voice may be distorted when this value exceeds 16384.
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 60 / 88 Table 19: Pin Definition of the ADC Table 20: Characteristics of the ADC 3.13. Behaviors Of The RI Table 21: Behaviors of the RI If URC of SMS is disabled, the RI will not change. Pin Name Pin No. Description ADC0 2 Analog to digital converter. Item Min. Typ. Max. Units Voltage Range 0 2.8 V ADC Resolution 10 bits ADC Accuracy 2.7 mV State RI response Standby HIGH Voice Calling Change to LOW, then: 1. Change to HIGH when call is established. 2. Use ATH to hang up the call, RI changes to HIGH. 3. Calling part hangs up, RI changes to HIGH first, and changes to LOW for 120ms indicating ―NO CARRIER‖ as an URC, then changes 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. NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 61 / 88 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 as below. RIIdle RingOff-hook by“ATA”On-hook by “ATH”SMS receivedHIGHLOW Figure 41: RI Behavior of Voice Calling as a Receiver RIIdle Calling On-hookTalkingHIGHLOWIdle Figure 42: RI Behavior as a Caller RIIdle or Talking URC or SMS received HIGHLOW120ms Figure 43: RI Behavior of URC or SMS Received
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 62 / 88 3.14. Network Status Indication The NETLIGHT signal can be used to drive a network status indicator LED. The working state of this pin is listed in the following table. Table 22: Working State of the NETLIGHT A reference circuit is shown as below. ModuleNETLIGHT 4.7K47K300RVBAT Figure 44: Reference Design for NETLIGHT 3.15. Operating Status Indication The STATUS pin will output a high level after the module being turned on, but it is not recommended connecting this pin to a MCU’s GPIO to judge whether the module is turn-on or not. The following LED indicator circuit for STATUS pin can be used to indicate the state after the module has been turned on. 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 The GPRS data transmission after dialing the PPP connection.
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 63 / 88 Table 23: Pin Definition of the STATUS Module300R4.7K47KVBATSTATUS Figure 45: Reference Design for STATUS Pin Name Pin No. Description STATUS 16 Indicate module operating status
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 64 / 88 4 Antenna Interface The Pin 63 is the RF antenna pad. The RF interface has an impedance of 50Ω. Table 24: Pin Definition of the RF_ANT 4.1. Reference Design The external antenna must be matched properly to achieve best performance, so the matching circuit is necessary, the reference design for RF is shown as below. ModuleRF_ANT0RNM NM Figure 46: Reference Design for RF Pin Name Pin No. Description GND 61 Ground GND 62 Ground RF_ANT 63 RF antenna pad GND 64 Ground GND 65 Ground GND 66 Ground
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 65 / 88 M85 provides an RF antenna pad for antenna connection. The RF trace in host PCB connected to the module RF antenna pad should be coplanar waveguide line or microstrip line, whose characteristic impedance should be close to 50Ω. M85 comes with grounding pads which are next to the antenna pad in order to give a better grounding. Besides, a π type match circuit is suggested to be used to adjust the RF performance. 4.2. RF Output Power Table 25: The Module Conducted RF Output Power 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 26: The Module Conducted RF Receiving Sensitivity Frequency Max. Min. GSM850 33dBm±2dB 5dBm±5dB EGSM900 33dBm±2dB 5dBm±5dB DCS1800 30dBm±2dB 0dBm±5dB PCS1900 30dBm±2dB 0dBm±5dB Frequency Receive Sensitivity GSM850 < -109dBm EGSM900 < -109dBm DCS1800 < -109dBm PCS1900 < -109dBm NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 66 / 88 4.4. Operating Frequencies Table 27: The Module Operating Frequencies 4.5. Antenna Requirement The following table shows the requirement on GSM antenna. Table 28: Antenna Cable Requirements Type Requirements GSM850/EGSM900 Cable insertion loss <1dB DCS1800/PCS1900 Cable insertion loss <1.5dB Table 29: Antenna Requirements Type Requirements Frequency Range GSM850/EGSM900/DCS1800/PCS1900MHz. VSWR ≤ 2 Gain (dBi) 1 Max Input Power (W) 50 Input Impedance (Ω) 50 Polarization Type Vertical 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
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 67 / 88 4.6. RF Cable Soldering Soldering the RF cable to RF pad of module correctly will reduce the loss on the path of RF, please refer to the following example of RF soldering. Figure 47: RF Soldering Sample
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 68 / 88 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 30: 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 3.08 V Voltage at analog pins -0.3 3.08 V Voltage at digital/analog pins in power down mode -0.25 0.25 V
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 69 / 88 5.2. Operating Temperature The operating temperature is listed in the following table: Table 31: Operating Temperature 1) When the module works within this temperature range, the deviation from the GSM specification may occur. For example, the frequency error or the phase error will be increased. 5.3. Power Supply Ratings Table 32: The Module Power Supply Ratings Parameter Min. Typ. Max. Unit Normal Temperature -35 +25 +80 ℃ Restricted Operation1) -40 ~ -35 +80 ~ +85 ℃ Storage Temperature -45 +90 ℃ 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 Voltage drop during transmitting burst Maximum power control level on GSM850 and EGSM900. 400 mV IVBAT Average supply current Power down mode SLEEP mode @DRX=5 150 1.3 uA mA Minimum functionality mode AT+CFUN=0 IDLE mode SLEEP mode 13 0.98 mA mA NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 70 / 88 1. 1) Power control level PCL 5. 2. 2) Power control level PCL 0. 3. 3) Under the GSM850 and EGSM900 spectrum, the power of 1Rx and 4Tx has been reduced. 5.4. Current Consumption The values of current consumption are shown as below. Table 33: The Module Current Consumption AT+CFUN=4 IDLE mode SLEEP mode 13 1.0 mA mA TALK mode GSM850/EGSM9001) DCS1800/PCS19002) 223/219 153/151 mA mA DATA mode, GPRS (3Rx,2Tx) GSM850/EGSM9001) DCS1800/PCS19002) 363/393 268/257 mA mA DATA mode, GPRS (2Rx,3Tx) GSM850/EGSM9001) DCS1800/PCS19002) 506/546 366/349 mA mA DATA mode, GPRS (4Rx,1Tx) GSM850/EGSM9001) DCS1800/PCS19002) 217/234 172/170 mA mA DATA mode, GPRS (1Rx,4Tx) GSM850/EGSM9001) DCS1800/PCS19002) 458/4853) 462/439 mA mA Peak supply current (during transmission slot) Maximum power control level on GSM850 and EGSM900. 1.6 2 A Condition Current Consumption Voice Call GSM850 @power level #5 <300mA, Typical 223mA NOTES
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 71 / 88 @power level #12, Typical 83mA @power level #19, Typical 62mA EGSM900 @power level #5 <300mA, Typical 219mA @power level #12, Typical 83mA @power level #19, Typical 63mA DCS1800 @power level #0 <250mA, Typical 153mA @power level #7, Typical 73mA @power level #15, Typical 60mA PCS1900 @power level #0 <250mA, Typical 151mA @power level #7, Typical 76mA @power level #15, Typical 61mA GPRS Data DATA Mode, GPRS (3Rx, 2Tx) CLASS 12 GSM850 @power level #5 <550mA, Typical 363mA @power level #12, Typical 131mA @power level #19, Typical 91mA EGSM900 @power level #5 <550mA, Typical 393mA @power level #12, Typical 132mA @power level #19, Typical 92mA DCS1800 @power level #0 <450mA, Typical 268mA @power level #7, Typical 112mA @power level #15, Typical 88mA PCS1900 @power level #0 <450mA, Typical 257mA @power level #7, Typical 119mA @power level #15, Typical 89mA DATA Mode, GPRS (2Rx, 3Tx) CLASS 12 GSM850 @power level #5 <640mA, Typical 506mA @power level #12, Typical 159mA @power level #19, Typical 99mA EGSM900 @power level #5 <600mA, Typical 546mA @power level #12, Typical 160mA @power level #19, Typical 101mA DCS1800 @power level #0 <490mA, Typical 366mA @power level #7, Typical 131mA @power level #15, Typical 93mA PCS1900 @power level #0 <480mA, Typical 348mA @power level #7, Typical 138mA @power level #15, Typical 94mA DATA Mode, GPRS (4Rx, 1Tx) CLASS 12
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 72 / 88 GPRS Class 12 is the default setting. The module can be configured from GPRS Class 1 to Class 12. Setting to lower GPRS class would make it easier to design the power supply for the module. 5.5. Electro-static Discharge Although the GSM engine is generally protected against Electro-static 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. GSM850 @power level #5 <350mA, Typical 216mA @power level #12, Typical 103mA @power level #19, Typical 83mA EGSM900 @power level #5 <350mA, Typical 233mA @power level #12, Typical 104mA @power level #19, Typical 84mA DCS1800 @power level #0 <300mA, Typical 171mA @power level #7, Typical 96mA @power level #15, Typical 82mA PCS1900 @power level #0 <300mA, Typical 169mA @power level #7, Typical 98mA @power level #15, Typical 83mA DATA Mode, GPRS (1Rx, 4Tx) CLASS 12 GSM850 @power level #5 <660mA, Typical 457mA @power level #12, Typical 182mA @power level #19, Typical 106mA EGSM900 @power level #5 <660mA, Typical 484mA @power level #12, Typical 187mA @power level #19, Typical 109mA DCS1800 @power level #0 <530mA, Typical 461mA @power level #7, Typical 149mA @power level #15, Typical 97mA PCS1900 @power level #0 <530mA, Typical 439mA @power level #7, Typical 159mA @power level #15, Typical 99mA NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 73 / 88 The measured ESD values of module are shown as the following table: Table 34: The ESD Endurance (Temperature: 25ºC , Humidity: 45%) Tested Point Contact Discharge Air Discharge VBAT, GND ±5KV ±10KV RF_ANT ±5KV ±10KV TXD, RXD ±2KV ±4KV Others ±0.5KV ±1KV
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 74 / 88 6 Mechanical Dimensions This chapter describes the mechanical dimensions of the module. 6.1. Mechanical Dimensions of Module Figure 48: M85 Module Top and Side Dimensions (Unit: mm)
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 75 / 88 Figure 49: M85 Module Bottom Dimensions (Unit: mm) Figure 50: The PAD Dimensions (Unit: mm)
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 76 / 88 6.2. Recommended Footprint Figure 51: Recommended Footprint (Unit: mm) The module should keep about 3mm away from other components in the host PCB. NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 77 / 88 6.3. Top View of the Module Figure 52: Top View of the Module 6.4. Bottom View of the Module Figure 53: Bottom View of the Module
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 78 / 88 7 Storage and Manufacturing 7.1. Storage M85 module is distributed in a vacuum-sealed bag. The restriction for storage is shown as below. Shelf life in the vacuum-sealed bag: 12 months at environments of <40ºC temperature and < 90%RH. After the vacuum-sealed bag is opened, devices that need to be mounted directly must be:  Mounted within 72 hours at the factory environment of ≤30ºC temperature and <60% RH.  Stored at <10% RH. Devices require baking before mounting, if any circumstance below occurs.  When the ambient temperature is 23ºC ±5 ºC , humidity indication card shows the humidity is >10% before opening the vacuum-sealed bag.  If ambient temperature is <30ºC and the humidity is <60%, the devices have not been mounted during 72hours.  Stored at >10% RH. If baking is required, devices should be baked for 48 hours at 125ºC ±5 ºC . As plastic container cannot be subjected to high temperature, devices must be removed prior to high temperature (125ºC ) bake. If shorter bake times are desired, refer to the IPC/JEDECJ-STD-033 for bake procedure. NOTE
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 79 / 88 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 0.2 mm for M85. For more details, please refer to document [13]. It is suggested that peak reflow temperature is from 235ºC to 245ºC (for SnAg3.0Cu0.5 alloy). Absolute max reflow temperature is 260ºC. 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. Time(s)50 100 150 200 250 30050100150200250 160℃ 200℃217070s~120s40s~60sBetween 1~3℃/SPreheat Heating Cooling℃sLiquids Temperature Figure 54: Ramp-Soak-Spike Reflow Profile
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 80 / 88 7.3. Packaging M85 modules are shipped in tape and reel form. The reel is 330mm in diameter and each reel contains 250pcs modules. This is especially suitable for the M85 according to SMT assembly processes requirements. The tape is packed in a vacuum-sealed bag which is ESD protected. Furthermore, it should not be opened until the devices are ready to be soldered onto the application. Direction of SMT
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 81 / 88 DC圆盘44PS6DETAIL:ADETAIL:A Figure 55: Tape and Reel Information Table 35: Reel Packing Model Name MOQ for MP Minimum Package: 250pcs Minimum Package×4=1000pcs M85 250pcs Size: 370 × 350 × 56mm N.W: 0.78kg G.W: 1.54kg Size: 380 × 250 × 365mm N.W: 3.10kg G.W: 6.80kg
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 82 / 88 8 Appendix A Reference Table 36: Related Documents SN Document Name Remark [1] Quectel_M85_AT_Commands_Manual AT commands manual [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] Quectel_GSM_UART_Application_Note UART port application note [11] Quectel_GSM_Module_Digital_IO_Application_Note GSM Module Digital IO Application Note
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 83 / 88 Table 37: Terms and Abbreviations [12] Quectel_GSM_EVB_User_Guide GSM EVB user guide [13] Quectel_Module_Secondary_SMT_User_Guide Module secondary SMT user guide 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
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 84 / 88 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 G.W Gross Weight 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 Li-Ion Lithium-Ion MO Mobile Originated MOQ Minimum Order Quantity MP Manufacture Product MS Mobile Station (GSM engine) MT Mobile Terminated N.W Net Weight
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 85 / 88 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
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 86 / 88 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 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 SM SIM phonebook
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 87 / 88 9 Appendix B GPRS Coding Scheme Four coding schemes are used in GPRS protocol. The differences between them are shown in the following table. Table 38: 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 the figure below. Figure 56: Radio Block Structure of CS-1, CS-2 and CS-3 Rate 1/2 convolutional coding Puncturing 456 bits USF BCS Radio Block
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 88 / 88 Radio block structure of CS-4 is shown as the following figure. Figure 57: Radio Block Structure of CS-4 Block Code No coding 456 bits USF BCS Radio Block
GSM/GPRS Module Series M85 Hardware Design M85_Hardware_Design Confidential / Released 89 / 88 10 Appendix C GPRS Multi-slot Class 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 the following table. Table 39: 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

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