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Quectel M85 Hardware Design

Gsm/gprs module series
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M85
Hardware Design
GSM/GPRS Module Series
Rev. M85_Hardware_Design_V1.0
Date: 2013-07-17
www.quectel.com

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Summary of Contents for Quectel M85

  • Page 1 Hardware Design GSM/GPRS Module Series Rev. M85_Hardware_Design_V1.0 Date: 2013-07-17 www.quectel.com...
  • Page 2 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.

  • Page 3: About The Document

    GSM/GPRS Module M85 Hardware Design About the document History Revision Date Author Description 2012-07-17 Winter CHEN Initial M85_Hardware_Design Confidential / Released 2 / 92...

  • Page 4: Table Of Contents

    GSM/GPRS Module M85 Hardware Design Contents About the document ........................... 2 Table Index ..............................6 Figure Index ..............................7 Introduction ............................9 1.1. Safety Information ........................9 Product Concept ..........................11 2.1. General Description ....................... 11 2.2. Key Features ......................... 11 2.3.
  • Page 5 GSM/GPRS Module M85 Hardware Design 3.7.4. UART Application ......................43 3.8. Audio Interfaces ........................45 3.8.1. Decrease TDD Noise and Other Noise ................46 3.8.2. Microphone Interfaces Design ..................47 3.8.3. Receiver and Speaker Interface Design ................ 48 3.8.4. Earphone Interface Design .................... 49 3.8.5.
  • Page 6 GSM/GPRS Module M85 Hardware Design 7.3. Packaging ..........................83 Appendix A Reference ........................85 Appendix B GPRS Coding Scheme ....................90 10 Appendix C GPRS Multi-slot Class ....................92 M85_Hardware_Design Confidential / Released 5 / 92...
  • Page 7 TABLE 1: MODULE KEY FEATURES ........................ 11 TABLE 2: CODING SCHEMES AND MAXIMUM NET DATA RATES OVER AIR INTERFACE ......13 TABLE 3: M85 PIN ASSIGNMENT ........................17 TABLE 4: PIN DESCRIPTION ........................... 18 TABLE 5: OVERVIEW OF OPERATING MODES ..................... 23 TABLE 6: SUMMARY OF STATE TRANSITION ....................
  • Page 8 GSM/GPRS Module M85 Hardware Design Figure Index FIGURE 1: MODULE FUNCTIONAL DIAGRAM ....................14 FIGURE 2: PIN ASSIGNMENT ......................... 16 FIGURE 3: VOLTAGE RIPPLE DURING TRANSMITTING ................25 FIGURE 4: REFERENCE CIRCUIT FOR THE VBAT INPUT ................26 FIGURE 5: REFERENCE CIRCUIT FOR POWER SUPPLY ................26 FIGURE 6: TURN ON THE MODULE WITH AN OPEN-COLLECTOR DRIVER ..........
  • Page 9 FIGURE 50: REFERENCE DESIGN FOR RF ....................68 FIGURE 51: RF SOLDERING SAMPLE ......................70 FIGURE 52: M85 MODULE TOP AND SIDE DIMENSIONS (UNIT: MM) ............77 FIGURE 53: M85 MODULE BOTTOM DIMENSIONS (UNIT: MM) ..............78 FIGURE 54: THE PAD DIMENSIONS (UNIT: MM) ................... 78 FIGURE 55: RECOMMENDED FOOTPRINT ( UNIT: MM ) ................

  • Page 10: Introduction

    If not so, Quectel does not take on any liability for customer failure to comply with these precautions.
  • Page 11 GSM/GPRS Module M85 Hardware Design GSM cellular terminals or mobiles operate over radio frequency signal and cellular network and cannot be guaranteed to connect in all conditions, for example no mobile fee or an invalid SIM card. While you are in this condition and need emergent help, Please Remember using emergency call.

  • Page 12: Product Concept

    M85 is an SMD type module with LCC package, which can be easily embedded into applications. It provides abundant hardware interfaces like PCM and Dual SIM 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.
  • Page 13 GSM/GPRS Module M85 Hardware Design  Quad-band: GSM850, GSM900, DCS1800, PCS1900.  The module can search these frequency bands automatically Frequency bands  The frequency bands can be set by AT command.  Compliant to GSM Phase 2/2+ GSM class Small MS ...

  • Page 14: Functional Diagram

    CS-3 15.6kbps 31.2kbps 62.4kbps CS-4 21.4kbps 42.8kbps 85.6kbps 2.3. Functional Diagram The following figure shows a block diagram of M85 and illustrates the major functional parts.  Serial Flash  Radio frequency part Power management  The Peripheral interface ...

  • Page 15: Evaluation Board

    Figure 1: Module functional diagram 2.4. 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.

  • Page 16: Application Interface

    GSM/GPRS Module M85 Hardware Design 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   Serial interfaces  Audio interfaces ...
  • Page 17 GSM/GPRS Module M85 Hardware Design RESERVED SIM1_VDD ADC0 SIM1_CLK RESERVED Top view SIM1_DATA NETLIGHT SIM1_RST SPK2P SIM_GND AGND RESERVED MIC2P MIC2N RESERVED MIC1P RESERVED MIC1N SPK1N RESERVED SPK1P RESERVED LOUDSPKN RESERVED DBG_RXD LOUDSPKP DBG_TXD PWRKEY RXD_AUX STATUS TXD_AUX EMERG_OFF PCM_IN...
  • Page 18 GSM/GPRS Module M85 Hardware Design Table 3: M85 Pin Assignment PIN NO. PIN NAME PIN NO. PIN NAME PIN NO. PIN NAME RESERVED ADC0 RESERVED NETLIGHT SPK2P AGND MIC2P MIC2N MIC1P MIC1N SPK1N SPK1P LOUDSPKN LOUDSPKP PWRKEY STATUS EMERG_OFF PCM_IN...

  • Page 19: Pin Description

    GSM/GPRS Module M85 Hardware Design VBAT SIM2_VDD SIM2_CLK SIM2_DATA SIM2_RST RESERVED RESERVED RESERVED RESERVED RESERVED NOTE Keep all reserved pins open. 3.1.2. Pin Description Table 4: Pin Description Power supply DESCRIPTION COMMENT NAME CHARACTERISTICS Make sure that supply sufficient Main power supply of module: Vmax= 4.6V...
  • Page 20 GSM/GPRS Module M85 Hardware Design when using this pin for power supply. 37,61, 62,64~ Ground 79~82, Turn on/off PIN NAME DESCRIPTION COMMENT CHARACTERISTICS VILmax= Power on/off key. PWRKEY 0.1×VBAT should be pulled down for a Pulled up to VBAT PWRKEY...
  • Page 21 GSM/GPRS Module M85 Hardware Design SPK1P Channel 1 positive and 1. If unused, keep SPK1N negative voice output these pins open. 2. Support both voice and ringtone SPK2P Channel 2 voice output output. Analog ground. Separate 1. If unused, keep...
  • Page 22 GSM/GPRS Module M85 Hardware Design PIN NAME DESCRIPTION COMMENT CHARACTERISTICS DBG_ Transmit data If unused, keep Same as above these pins open. DBG_ Receive data Auxiliary Port PIN NAME DESCRIPTION COMMENT CHARACTERISTICS TXD_ Transmit data If unused, keep Same as above these pins open.
  • Page 23 GSM/GPRS Module M85 Hardware Design SIM_VDD-0.4 3V： SIM1_RST VOLmax=0.36 VOHmin= 0.9×SIM_VDD SIM reset 1.8V: SIM2_RST VOLmax= 0.2×SIM_VDD VOHmin= 0.9×SIM_VDD VILmin=0V VILmax= 0.25×VDD_EXT SIM1_ If unused, keep SIM card detection VIHmin= PRESENCE these pins open. 0.75×VDD_EXT VIHmax= VDD_EXT+0.3 SIM_ SIM ground...

  • Page 24: Operating Modes

    GSM/GPRS Module M85 Hardware Design DESCRIPTION COMMENT NAME CHARACTERISTICS VILmin=0V SD command VILmax= 0.25×VDD_EXT SD clock VIHmin= 0.75×VDD_EXT VIHmax= VDD_EXT+0.3 SD data VOHmin= DATA0 0.85×VDD_EXT VOLmax= 0.15×VDD_EXT RF interface DESCRIPTION COMMENT NAME CHARACTERISTICS RF antenna pad Impedance of 50Ω Other interface...
  • Page 25 GSM/GPRS Module M85 Hardware Design 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. Software is active. The module has registered to the GSM...

  • Page 26: Power Supply

    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.

  • Page 27: Reference Design For Power Supply

    GSM/GPRS Module M85 Hardware Design VBAT 100uF 100nF 10pF 33pF 0603 0603 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.

  • Page 28: Monitor Power Supply

    Figure 6: Turn on the Module with an Open-collector Driver NOTE 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 receives AT command, it will be powered on after a delay of 2 or 3 seconds.
  • Page 29 GSM/GPRS Module M85 Hardware Design ―AT‖ or ―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 configurations, the URC ―RDY‖...

  • Page 30: Power Down

    GSM/GPRS Module M85 Hardware Design NOTES 1. Make sure that VBAT is stable before pulling down PWRKEY pin. The time of T is recommended 30ms. EMERG_OFF should be floated when it is unused 3.4.2. Power Down The following procedures can be used to turn off the module: ...

  • Page 31: Power Down Module Using At Command

    GSM/GPRS Module M85 Hardware Design 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. Before the completion of the power down procedure, the module sends out the result code shown below:...

  • Page 32: Emergency Shutdown Using Emerg_Off Pin

    GSM/GPRS Module M85 Hardware Design If the voltage is ≥ 4.5V, the following URC will be presented: OVER_VOLTAGE WARNING 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 shutdown itself.

  • Page 33: Restart

    GSM/GPRS Module M85 Hardware Design EMERG_OFF TVS2 Close to S2 Figure 11: Reference Circuit for EMERG_OFF by Using Button 3.4.3. Restart Customer can restart the module by driving the PWRKEY to a low level voltage for a certain time, which is similar to the way of turning on module.

  • Page 34: Power Saving

    GSM/GPRS Module M85 Hardware Design Pulldown Delay >2s EMERG_OFF >20ms (INPUT) STATUS (OUTPUT) PWRKEY (INPUT) Figure 13: Timing of Restarting System after Emergency Shutdown 3.5. Power Saving Based on system requirements, there are several actions to drive the module to enter low current consumption status.

  • Page 35: Sleep Mode

    GSM/GPRS Module M85 Hardware Design 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.

  • Page 36: Rtc Backup

    GPRS 3.6. RTC Backup The RTC (Real Time Clock) function is supported by M85 module. The RTC is designed to work with an external 32.768KHZ crystal and an internal power supply. If VBAT voltage is not present, a backup power supply such as a coin-cell battery (rechargeable or non-chargeable) or a super-cap can be used.

  • Page 37: Serial Interfaces

    GSM/GPRS Module M85 Hardware Design Module 1.5K VRTC RTC Core Large Capacitance Capacitor Figure 16: RTC Supply from a Capacitor The following figure shows the charging characteristics of a coin-type rechargeable battery XH414H-IV01E from Seiko. Figure 17: Charging Characteristics of Seiko’s XH414H-IV01E 3.7.
  • Page 38 GSM/GPRS Module M85 Hardware Design  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 the call, SMS, data of the module are coming, the module will output signal to inform DTE).

  • Page 39: Uart Port

    GSM/GPRS Module M85 Hardware Design DBG_TXD Transmit data Data carrier detection Ring indication Data terminal ready UART Port Clear to send Transmit data Receive data Request to send TXD_AUX Transmit data Auxiliary UART Port RXD_AUX Receive data 3.7.1. UART Port 3.7.1.1.

  • Page 40: The Connection Of Uart

    GSM/GPRS Module M85 Hardware Design Synchronization between DTE and DCE: When DCE (the module) powers on with the autobauding enabled, it is recommended to wait 2 to 3 seconds before sending the first AT character. After receiving the ―OK‖ response, DTE and DCE are correctly synchronized.
  • Page 41 GSM/GPRS Module M85 Hardware Design Module (DCE) PC (DTE) UART port Serial port RING Figure 18: Reference Design for Full-Function UART Three-line connection is shown as below. Module (DCE) Host (DTE) Controller UART port Figure 19: Reference Design for UART Port UART Port with hardware flow control is shown as below.

  • Page 42: Firmware Upgrade

    GSM/GPRS Module M85 Hardware Design Host (DTE) Module (DCE) Controller Figure 20: 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.

  • Page 43: Debug Port

    GSM/GPRS Module M85 Hardware Design 3.7.2. Debug Port 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.

  • Page 44: Uart Application

    GSM/GPRS Module M85 Hardware Design Module Peripheral TXD_AUX RXD_AUX Figure 23: 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.
  • Page 45 GSM/GPRS Module M85 Hardware Design As to the circuit below, VDD_EXT supplies power for the I/O of module, while VCC_MCU supplies power for the I/O of the peripheral. 4.7K VDD_EXT VCC_MCU 5.6K Module Peripheral 4.7K /TXD /RXD 4.7K 4.7K VDD_EXT...

  • Page 46: Audio Interfaces

    GSM/GPRS Module M85 Hardware Design 3.8. Audio Interfaces The module provides two analogy input channels and three analogy output channels. Table 9: Pin definition of Audio interface Interface Name Pin NO. Description MIC1P Channel 1 Microphone positive input MIC1N Channel 1 Microphone negative input...

  • Page 47: Decrease Tdd Noise And Other Noise

    GSM/GPRS Module M85 Hardware Design 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‖...

  • Page 48: Microphone Interfaces Design

    GSM/GPRS Module M85 Hardware Design 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.

  • Page 49: Receiver And Speaker Interface Design

    GSM/GPRS Module M85 Hardware Design 3.8.3. Receiver and Speaker Interface Design Close to speaker 10pF 33pF Differential layout 0603 0603 Module SPK1P 33pF 10pF 0603 0603 SPK1N 10pF 33pF 0603 0603 Figure 28: Reference Design for AOUT1 Close to Speaker...

  • Page 50: Earphone Interface Design

    GSM/GPRS Module M85 Hardware Design Close to Speaker Differential layout Amplifier 10pF 33pF 0603 circuit 0603 SPK2P Module AGND 33pF 10pF 0603 0603 Figure 30: Speaker Interface Design with an Amplifier for AOUT2 Texas Instrument’s TPA6205A1is recommended for a suitable differential audio amplifier. There are plenty of excellent audio amplifiers in the market.

  • Page 51: Loud Speaker Interface Design

    GSM/GPRS Module M85 Hardware Design 3.8.5. Loud Speaker Interface Design Close to Speaker Differential layout 10pF 33pF 0603 0603 LOUDSPKP Module 100pF LOUDSPKN 10pF 33pF 0603 0603 Figure 32: Loud Speaker Interface Design 3.8.6. Audio Characteristics Table 11: Typical Electret Microphone Characteristics Parameter Min.

  • Page 52: Dual-Sim Card Interface

    In dual SIM card mode, configure ―AT + QDSIM = 0‖ to use the SIM1 interface and configure ―AT + QDSIM= 1‖ to use SIM2 interface. M85 is set to SIM1 Mode by default. For more details, please refer to the document [1].
  • Page 53 GSM/GPRS Module M85 Hardware Design SIM1_RST SIM card reset. SIM2_RST SIM1_PRESENCE SIM1 card detection. SIM_GND SIM card ground. In Figure 33, the pin SIM_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 or not. When the tray is inserted in the socket, SIM_PRESENCE is at low level.
  • Page 54 GSM/GPRS Module M85 Hardware Design NOTE Please do not use ―AT+QSIMDET=1,1‖ which causes to initialize SIM card when Figure 33 circuit is adopted. If the SIM1 card detection function is not used, keep SIM_PRESENCE pin open. The reference circuit for a 6-pin SIM card socket is illustrated as the following figure.

  • Page 55: Pin Sim Cassette

    GSM/GPRS Module M85 Hardware Design In order to enhance the reliability and availability of the SIM card in application. Please follow the below criterion in the SIM circuit design.  Keep layout of SIM card as close as possible to the module. Assure the possibility of the length of the trace is less than 200mm.
  • Page 56 GSM/GPRS Module M85 Hardware Design Figure 36: Amphenol C707 10M006 512 2 SIM Card Holder Table 14: Pin Description of Amphenol SIM Card Holder Name Description SIM_VDD SIM card power supply SIM_RST SIM card reset SIM_CLK SIM card clock Ground...

  • Page 57: 8-Pin Sim Card Holder

    GSM/GPRS Module M85 Hardware Design 3.9.3. 8-Pin SIM Card Holder As to 8-pin SIM card holder, it is recommended to use Molex 91228. Please visit http://www.molex.com for more information. Figure 37: Molex 91228 SIM card holder Table 15: Pin Description of Molex SIM Card Holder...

  • Page 58: Sd Card Interface

    GSM/GPRS Module M85 Hardware Design SIM_DATA SIM card data I/O SIM_DETECT Pulled down GND with external circuit. When the tray is present, C4 is connected to C8. 3.10. SD Card Interface The module provides SD card interface that support many types of memory, such as Memory Stick, SD/MCC card and T-Flash or Micro SD card.
  • Page 59 GSM/GPRS Module M85 Hardware Design VDD_EXT 47K 47K SD Socket Module DATA2 CD/DATA3 SD_CMD VSS1 SD_CLK VSS2 DATA0 SD_DATA DATA1 4.7uF 0.1nF Figure 38: Reference Circuit for Micro SD Card Table 17: Pin Definition for SD/MMC Pin name Pin NO.

  • Page 60: Pcm Interface

    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.

  • Page 61: Timing

    GSM/GPRS Module M85 Hardware Design Table 19: Configuration Line interface Format Linear Data length Linear：13 bits Sample rate 8KHz PCM master mode: clock and synchronization is PCM clock/synchronization source generated by module PCM synchronization rate 8KHz PCM clock rate PCM master mode:256 KHz(line)
  • Page 62 GSM/GPRS Module M85 Hardware Design PCM_CLK PCM_SYN PCM_OUT Zero padding PCM_IN Zero padding Figure 40: Long Synchronization & Zero Padding Diagram PCM_CLK PCM_SYN PCM_OUT Sign extension PCM_IN Sign extension Figure 41: Short synchronization & Sign Extension Diagram PCM_CLK PCM_SYN PCM_OUT...

  • Page 63: Reference Design

    GSM/GPRS Module M85 Hardware Design 3.11.3. Reference Design M85 can only work as a master, providing synchronization and clock source. The reference design is shown as below. Peripheral Module (Slave) (Master) PCM_CLK PCM_CLK PCM_SYNC PCM_SYNC PCM_OUT PCM_IN PCM_OUT PCM_IN Figure 43: Reference Design for PCM 3.11.4.

  • Page 64: Adc

    GSM/GPRS Module M85 Hardware Design NOTES 1. ―AT+QPCMVOL‖ can configure the volume of input and output. 2. AT+QPCMVOL=vol_pcm_in,vol_pcm_out Table 21: QPCMVOL Command Description Parameter scope Description vol_pcm_in 0~32767 Set the input volume Set the output volume vol_pcm_out 0~32767 The voice may be distorted when this value exceeds 16384.

  • Page 65: Behaviors Of The Ri

    GSM/GPRS Module M85 Hardware Design 3.13. Behaviors Of The RI Table 24: Behaviors of the RI State RI response Standby HIGH Change to LOW, then: 1. Change to HIGH when call is established. 2. Use ATH to hang up the call, RI changes to HIGH.
  • Page 66 GSM/GPRS Module M85 Hardware Design HIGH Data calling establish On-hook by “ATH” SMS received Idle Ring Figure 45: RI Behavior of Data Calling as a Receiver HIGH Idle Calling Talking Idle On-hook Figure 46: RI Behavior as a Caller 120ms...

  • Page 67: Network Status Indication

    GSM/GPRS Module M85 Hardware Design 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 25: Working State of the NETLIGHT...
  • Page 68 GSM/GPRS Module M85 Hardware Design Table 26: Pin Definition of the STATUS Name Description STATUS Indicate module operating status VBAT 300R Module 4.7K STATUS Figure 49: Reference Design for STATUS M85_Hardware_Design Confidential / Released 67 / 92...

  • Page 69: Antenna Interface

    GSM/GPRS Module M85 Hardware Design Antenna Interface The Pin 63 is the RF antenna pad. The RF interface has an impedance of 50Ω. Table 27: Pin Definition of the RF_ANT Name Description Ground Ground RF_ANT RF antenna pad Ground Ground Ground 4.1.

  • Page 70: Rf Output Power

    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 ∏ type match circuit is suggested to be used to adjust the RF performance.

  • Page 71: Operating Frequencies

    GSM/GPRS Module M85 Hardware Design DCS1800 < -108.5dBm PCS1900 < -108.5dBm 4.4. Operating Frequencies Table 30: The Module Operating Frequencies Frequency Receive Transmit ARFCH GSM850 869~894MHz 824~849MHz 128~251 EGSM900 925~960MHz 880~915MHz 0~124, 975~1023 DCS1800 1805~1880MHz 1710~1785MHz 512~885 PCS1900 1930~1990MHz 1850~1910MHz 512~810 4.5.

  • Page 72: Electrical, Reliability And Radio Characteristics

    GSM/GPRS Module M85 Hardware Design 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 31: Absolute Maximum Ratings...

  • Page 73: Power Supply Ratings

    GSM/GPRS Module M85 Hardware Design Storage Temperature ℃ NOTE 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...

  • Page 74: Current Consumption

    GSM/GPRS Module M85 Hardware Design GSM850/EGSM 900 435/400 DCS1800/PCS1900 313/337 DATA mode, GPRS(2 Rx,3Tx) GSM850/EGSM 900 605/558 DCS1800/PCS1900 399/460 DATA mode, GPRS (4 Rx,1Tx) GSM850/EGSM 900 265/240 DCS1800/PCS1900 200/212 DATA mode, GPRS (1Rx,4Tx) GSM850/EGSM 900 615/560 DCS1800/PCS1900 420/470 Peak supply...
  • Page 75 GSM/GPRS Module M85 Hardware Design @power level #15,Typical 70mA @power level #0 <250mA,Typical 202mA PCS1900 @power level #7,Typical 95mA @power level #15,Typical 71mA GPRS Data DATA mode, GPRS ( 1 Rx,1 Tx ) CLASS 12 @power level #5 <350mA,Typical 199mA...
  • Page 76 GSM/GPRS Module M85 Hardware Design @power level #7,Typical 150mA @power level #15,Typical 94mA @power level #0 <480mA,Typical 460mA PCS 1900 @power level #7,Typical 166mA @power level #15,Typical 98mA DATA mode, GPRS ( 4 Rx,1 Tx ) CLASS 12 @power level #5 <350mA,Typical 265mA...

  • Page 77: Electro-Static Discharge

    GSM/GPRS Module M85 Hardware Design 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.

  • Page 78: Mechanical Dimensions

    GSM/GPRS Module M85 Hardware Design Mechanical Dimensions This chapter describes the mechanical dimensions of the module. 6.1. Mechanical Dimensions Of Module Figure 52: M85 Module Top and Side Dimensions (Unit: mm) M85_Hardware_Design Confidential / Released 77 / 92...
  • Page 79 GSM/GPRS Module M85 Hardware Design Figure 53: M85 Module Bottom Dimensions (Unit: mm) Figure 54: The PAD Dimensions (Unit: mm) M85_Hardware_Design Confidential / Released 78 / 92...

  • Page 80: Recommended Footprint

    GSM/GPRS Module M85 Hardware Design 6.2. Recommended Footprint Figure 55: Recommended Footprint ( Unit: mm ) NOTE The module should keep about 3mm away from other components in the host PCB. M85_Hardware_Design Confidential / Released 79 / 92...

  • Page 81: Top View Of The Module

    GSM/GPRS Module M85 Hardware Design 6.3. Top View of the Module Figure 56: Top View of the Module 6.4. Bottom View of the Module Figure 57: Bottom View of the Module M85_Hardware_Design Confidential / Released 80 / 92...

  • Page 82: Storage And Manufacturing

    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 <40℃ temperature and < 90%RH. After the vacuum-sealed bag is opened, devices that need to be mounted directly must be: ...

  • Page 83: Soldering

    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 235 º C to 245º C (for SnAg3.0Cu0.5 alloy). Absolute max reflow temperature is 260º...
  • Page 84 GSM/GPRS Module M85 Hardware Design 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.
  • Page 85 GSM/GPRS Module M85 Hardware Design DETAIL:A DC 圆盘44 DETAIL:A Figure 59: Tape and Reel Information M85_Hardware_Design Confidential / Released 84 / 92...
  • Page 86 GSM/GPRS Module M85 Hardware Design Appendix A Reference Table 36: Related Documents Document name Remark M85_AT_Commands_Manual AT commands manual ITU-T Draft new recommendation Serial asynchronous automatic dialing and control V.25ter Digital cellular telecommunications (Phase 2+); AT GSM 07.07 command set for GSM Mobile Equipment (ME) GSM 07.10...
  • Page 87 GSM/GPRS Module M85 Hardware Design Table 37: Terms and Abbreviations Abbreviation Description Analog-to-Digital Converter Adaptive Multi-Rate Antenna Reference Point ASIC Application Specific Integrated Circuit Bit Error Rate Bill Of Material Base Transceiver Station CHAP Challenge Handshake Authentication Protocol Coding Scheme...
  • Page 88 GSM/GPRS Module M85 Hardware Design Federal Communications Commission (U.S.) FDMA Frequency Division Multiple Access Full Rate GMSK Gaussian Minimum Shift Keying GPRS General Packet Radio Service Global System for Mobile Communications Gross Weight Half Rate Input/Output Integrated Circuit IMEI International Mobile Equipment Identity...
  • Page 89 GSM/GPRS Module M85 Hardware Design Protocol Data Unit Point-to-Point Protocol Radio Frequency Root Mean Square (value) Real Time Clock Receive Direction Subscriber Identification Module Short Message Service TDMA Time Division Multiple Access Terminal Equipment Transmitting Direction UART Universal Asynchronous Receiver & Transmitter...
  • Page 90 GSM/GPRS Module M85 Hardware Design VOHmin Minimum Output High Level Voltage Value VOLmax Maximum Output Low Level Voltage Value VOLmin Minimum Output Low Level Voltage Value Phonebook Abbreviations SIM Last Dialing phonebook (list of numbers most recently dialed) Mobile Equipment list of unanswered MT Calls (missed calls)
  • Page 91 GSM/GPRS Module M85 Hardware Design 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 Radio Pre-co Data Code Block...
  • Page 92 GSM/GPRS Module M85 Hardware Design Radio block structure of CS-4 is shown as the following figure. Radio Block Block No coding Code 456 bits Figure 61: Radio Block Structure of CS-4 M85_Hardware_Design Confidential / Released 91 / 92...
  • Page 93 GSM/GPRS Module M85 Hardware Design 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.

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