M85 Hardware Design GSM/GPRS Module Series Rev. M85_Hardware_Design_V3.0 Date: 2015-10-22 www.quectel.
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GSM/GPRS Module Series M85 Hardware Design 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 1. 2. 3. 4. 3.0 2015-03-13 Stone YU/ Hollis WANG 5. 6. 7. 8. 9.
GSM/GPRS Module Series M85 Hardware Design Contents About the Document ................................................................................................................................... 2 Contents ....................................................................................................................................................... 3 Table Index ...................................................................................................................................
GSM/GPRS Module Series M85 Hardware Design 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 ................................
GSM/GPRS Module Series M85 Hardware Design 6.4. Bottom View of the Module ................................................................................................... 77 7 Storage and Manufacturing .............................................................................................................. 78 7.1. Storage .................................................................................................................................. 78 7.2. Soldering ...........................
GSM/GPRS Module Series M85 Hardware Design 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 .........................
GSM/GPRS Module Series M85 Hardware Design Figure Index FIGURE 1: MODULE FUNCTIONAL DIAGRAM ............................................................................................... 15 FIGURE 2: PIN ASSIGNMENT ......................................................................................................................... 17 FIGURE 3: VOLTAGE RIPPLE DURING TRANSMITTING ..............................................................................
GSM/GPRS Module Series M85 Hardware Design 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 ............................................
GSM/GPRS Module Series M85 Hardware Design 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 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.
GSM/GPRS Module Series M85 Hardware Design 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.
GSM/GPRS Module Series M85 Hardware Design 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.
GSM/GPRS Module Series M85 Hardware Design GPRS multi-slot class 12 (default) GPRS multi-slot class 1~12 (configurable) GPRS mobile station class B GPRS data downlink transfer: max. 85.6kbps GPRS data uplink transfer: max. 85.
GSM/GPRS Module Series M85 Hardware Design 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 NOTE 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.
GSM/GPRS Module Series M85 Hardware Design —RF interface RF_ANT ESD RF PAM VBAT PWRKEY PMU EMERG_OFF Reset VRTC RTC SIM Interfaces GPIO& Status& Netlight UART RF Transceiver BB&RF SIM Interface GPIO&PWM Serial Interface MEMORY 26MHz ADC ADC PCM Interface PCM SD Interface SD Audio Audio Serial Flash Figure 1: Module Functional Diagram 2.5.
GSM/GPRS Module Series M85 Hardware Design 3 Application Interface The module adopts LCC package and has 83 pins. The following chapters provide detailed descriptions about these pins below.
GSM/GPRS Module Series M85 Hardware Design 3.1. Pin of Module SIM1_PRESENCE VRTC RESERVED VDD_EXT GND RF_ANT GND GND GND VBAT GND VBAT VBAT VBAT SIM2_CLK SIM2_VDD SIM2_DATA SIM2_RST 3.1.1.
GSM/GPRS Module Series M85 Hardware Design 3.1.2. Pin Description Table 3: Pin Description Power Supply PIN NAME VBAT VRTC PIN NO. I/O 67, 68, 69, 70 I 59 VDD_EXT 60 GND 37, 61, 62, 64~66, 79~82, I/O O DC CHARACTERISTICS COMMENT 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. Power supply for RTC. Charging for backup battery or golden capacitor when the VBAT is applied.
GSM/GPRS Module Series M85 Hardware Design PIN NAME EMERG_ OFF PIN NO. 17 DC CHARACTERISTICS I/O DESCRIPTION COMMENT 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 I/O DESCRIPTION DC CHARACTERISTICS COMMENT O Indicate module’s operating status. Output high level when module turns on, while output low level when module turns off.
GSM/GPRS Module Series M85 Hardware Design ringtone output. Network Status Indicator PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT If unused, keep this pin open. 4 O Network status indication VOHmin= 0.85×VDD_EXT VOLmax= 0.15×VDD_EXT PIN NAME PIN NO.
GSM/GPRS Module Series M85 Hardware Design SIM1_VDD 56 O SIM2_VDD 71 SIM1_CLK 55 O SIM2_CLK SIM1_ DATA Power supply for SIM card The voltage can be selected by software automatically. Either 1.8V or 3V. SIM clock VOLmax= 0.15×SIM_VDD VOHmin= 0.85×SIM_VDD SIM data VILmax= 0.25×SIM_VDD VIHmin= 0.75×SIM_VDD VOLmax= 0.15×SIM_VDD VOHmin= 0.85×SIM_VDD SIM reset VOLmax= 0.15×SIM_VDD VOHmin= 0.85×SIM_VDD SIM card detection VILmin=0V VILmax= 0.25×VDD_EXT VIHmin= 0.75×VDD_EXT VIHmax= VDD_EXT+0.
GSM/GPRS Module Series M85 Hardware Design PCM_OUT PCM_SYNC 20 O PCM data output 21 O PCM frame synchronization PIN NO. I/O DESCRIPTION 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. DC CHARACTERISTICS COMMENT 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.
GSM/GPRS Module Series M85 Hardware Design 3.2. Operating Modes The table below briefly summarizes the various operating modes in the following chapters. Table 4: Overview of Operating Modes Mode Normal Operation Function 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).
GSM/GPRS Module Series M85 Hardware Design NOTE 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.
GSM/GPRS Module Series M85 Hardware Design VBAT + C1 100uF C2 100nF C3 C4 10pF 33pF 0603 0603 GND 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.
GSM/GPRS Module Series M85 Hardware Design NOTE 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.
GSM/GPRS Module Series M85 Hardware Design 2. 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]. 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.
GSM/GPRS Module Series M85 Hardware Design NOTES 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.
GSM/GPRS Module Series M85 Hardware Design 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. NOTES 1. 2. 3.
GSM/GPRS Module Series M85 Hardware Design 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. NOTES 1.
GSM/GPRS Module Series M85 Hardware Design K2 EMERG_OFF TVS2 Close 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.
GSM/GPRS Module Series M85 Hardware Design The module can also be restarted by the PWRKEY after emergency shutdown. EMERG_OFF (INPUT) Pulldown >40ms Delay >500ms STATUS (OUTPUT) PWRKEY (INPUT) Figure 13: Timing of Restarting System after Emergency Shutdown NOTE 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.
GSM/GPRS Module Series M85 Hardware Design 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.
GSM/GPRS Module Series M85 Hardware Design Normal Mode SLEEP Mode Use AT command AT+QSCLK=1 and pull up DTR AT+QPOWD, use PWRKEY pin, or use EMERG_OFF pin Use PWRKEY pin, or use EMERG_OFF pin Pull DTR down or incoming voice call or SMS or GPRS data transmission 3.6. RTC Backup The RTC (Real Time Clock) function is supported. The RTC is designed to work with an internal power supply.
GSM/GPRS Module Series M85 Hardware Design Module RTC Core Power Supply LDO/DCDC VBAT VRTC LDO 1.5K Non-chargeable Backup Battery Figure 14: VRTC is Supplied by a Non-chargeable Battery Module RTC Core Power Supply LDO/DCDC VBAT VRTC LDO 1.
GSM/GPRS Module Series M85 Hardware Design Module RTC Core Power Supply LDO/DCDC VBAT VRTC LDO 1.5K Large 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/. NOTE 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.
GSM/GPRS Module Series M85 Hardware Design NOTE 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.
GSM/GPRS Module Series M85 Hardware Design DTR 47 Data terminal ready CTS 48 Clear to send TXD 49 Transmit data RXD 50 Receive data RTS 51 Request to send TXD_AUX 40 Transmit data RXD_AUX 41 Receive data Auxiliary UART Port 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.
GSM/GPRS Module Series M85 Hardware Design 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‖).
GSM/GPRS Module Series M85 Hardware Design Three-line connection is shown as below. Host (DTE) Controller Module (DCE) UART port TXD TXD RXD RXD GND GND 0R RTS 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. Host (DTE) Controller Module (DCE) TXD TXD RXD RXD RTS RTS CTS CTS GND GND Figure 19: Reference Design for UART Port with Hardware Flow Control 3.7.1.3.
GSM/GPRS Module Series M85 Hardware Design Module (DCE) IO Connector UART port TXD TXD RXD RXD GND GND PWRKEY PWRKEY Figure 20: Reference Design for Firmware Upgrade NOTE 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.
GSM/GPRS Module Series M85 Hardware Design 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.
GSM/GPRS Module Series M85 Hardware Design NOTE 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.
GSM/GPRS Module Series M85 Hardware Design 3.8. Audio Interfaces The module provides two analogy input channels and three analogy output channels. Table 8: Pin Definition of Audio Interface Interface Pin Name Pin No.
GSM/GPRS Module Series 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 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].
GSM/GPRS Module Series M85 Hardware Design 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. Close to Microphone GND Differential layout GND GND 10pF 0603 33pF 0603 10pF 0603 33pF 0603 10pF 0603 33pF 0603 ESD MICxP Module MICxN GND Electret Microphone ESD GND GND Figure 25: Reference Design for AIN1&AIN2 3.8.3.
GSM/GPRS Module Series M85 Hardware Design Close to speaker GND Differential layout 10pF 0603 33pF 0603 10pF 0603 33pF 0603 10pF 0603 33pF 0603 ESD Amplifier circuit SPK1P Module SPK1N ESD GND Figure 27: Speaker Interface Design with an Amplifier for AOUT1 Close to Speaker GND Differential layout SPK2P Module 10pF 0603 33pF 0603 ESD 22uF AGND Figure 28: Handset Interface Design for AOUT2 M85_Hardware_Design Confidential / Released 47 / 88
GSM/GPRS Module Series M85 Hardware Design Close to Speaker GND Differential layout Amplifier circuit 10pF 0603 33pF 0603 10pF 0603 33pF 0603 ESD C1 SPK2P Module AGND C2 ESD GND 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.
GSM/GPRS Module Series M85 Hardware Design 3.8.5. Loud Speaker Interface Design Close to Speaker GND Differential layout 10pF 0603 33pF 0603 0R ESD LOUDSPKP Module 100pF 0R LOUDSPKN 10pF 0603 33pF 0603 ESD GND Figure 31: Loud Speaker Interface Design 3.8.6. Audio Characteristics Table 10: Typical Electret Microphone Characteristics Parameter Min. Typ. Max. Unit Working Voltage 1.2 1.5 2.0 V Working Current 200 500 uA External Microphone Load Resistance 2.
GSM/GPRS Module Series M85 Hardware Design AOUT2 Output AOUT3 Output Load resistance 32 Ohm Single-ended Ref level 0 Load resistance 2.4 8 Vpp Ohm Differential Ref level 0 2×VBAT Vpp 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.
GSM/GPRS Module Series M85 Hardware Design SIM1_PRESENCE 57 SIM1 card detection SIM_GND 52 SIM card ground 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.
GSM/GPRS Module Series M85 Hardware Design 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.
GSM/GPRS Module Series M85 Hardware Design 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.
GSM/GPRS Module Series M85 Hardware Design Table 13: 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 VDD_EXT 47K 47K 9 1 2 3 4 5 6 7 8 33R SD_CMD 33R SD_CLK 33R SD_DATA0 SD Socket 47K Module 4.7uF DATA2 CD/DATA3 CMD VSS1 VDD CLK VSS2 DATA0 DATA1 0.
GSM/GPRS Module Series M85 Hardware Design 8 DATA1 9 DATA2 DATA1 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.
GSM/GPRS Module Series M85 Hardware Design 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.
GSM/GPRS Module Series M85 Hardware Design PCM_CLK PCM_SYNC MSB PCM_OUT Sign extension 12 11 10 9 8 7 6 5 4 3 2 1 0 12 11 10 9 8 7 6 5 4 3 2 1 0 MSB PCM_IN Sign extension Figure 36: Long Synchronization & Sign Extension Diagram PCM_CLK PCM_SYNC MSB PCM_OUT 12 11 10 9 8 7 6 5 4 3 2 1 0 Zero padding 8 7 6 5 4 3 2 1 0 Zero padding MSB PCM_IN 12 11 10 9 Figure 37: Long Synchronization & Zero Padding Diagram PCM_CLK PCM_SYNC MSB PCM_OUT Sign extension 12 1
GSM/GPRS Module Series M85 Hardware Design PCM_CLK PCM_SYNC MSB PCM_OUT 12 11 10 9 8 7 6 5 4 3 2 1 0 Zero padding 9 8 7 6 5 4 3 2 1 0 Zero padding MSB PCM_IN 12 11 10 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.
GSM/GPRS Module Series M85 Hardware Design Table 17: QPCMON Command Description 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 AT+QPCMVOL can configure the volume of input and output.
GSM/GPRS Module Series M85 Hardware Design Table 19: Pin Definition of the ADC Pin Name Pin No. Description ADC0 2 Analog to digital converter. Table 20: Characteristics of the ADC Item Min. Voltage Range 0 Typ. Max. Units 2.8 V ADC Resolution 10 bits ADC Accuracy 2.7 mV 3.13. Behaviors Of The RI Table 21: Behaviors of the RI State RI response Standby HIGH Voice Calling Change to LOW, then: 1. Change to HIGH when call is established. 2.
GSM/GPRS Module Series M85 Hardware Design 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.
GSM/GPRS Module Series 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 22: Working State of the NETLIGHT State Module function Off The module is not running. 64ms On/800ms Off The module is not synchronized with network. 64ms On/2000ms Off The module is synchronized with network.
GSM/GPRS Module Series M85 Hardware Design Table 23: Pin Definition of the STATUS Pin Name Pin No. Description STATUS 16 Indicate module operating status VBAT 300R Module 4.
GSM/GPRS Module Series M85 Hardware Design 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 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 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.
GSM/GPRS Module Series M85 Hardware Design 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.
GSM/GPRS Module Series M85 Hardware Design 4.4. Operating Frequencies Table 27: 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. Antenna Requirement The following table shows the requirement on GSM antenna.
GSM/GPRS Module Series M85 Hardware Design 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.
GSM/GPRS Module Series M85 Hardware Design 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.
GSM/GPRS Module Series M85 Hardware Design 5.2. Operating Temperature The operating temperature is listed in the following table: Table 31: Operating Temperature Parameter Min. Typ. Max. Unit Normal Temperature -35 +25 +80 ℃ Restricted Operation1) -40 ~ -35 +80 ~ +85 ℃ Storage Temperature -45 +90 ℃ NOTE 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.
GSM/GPRS Module Series M85 Hardware Design Peak supply current (during transmission slot) AT+CFUN=4 IDLE mode SLEEP mode 13 1.
GSM/GPRS Module Series M85 Hardware Design @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,
GSM/GPRS Module Series M85 Hardware Design 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) CL
GSM/GPRS Module Series M85 Hardware Design 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.
GSM/GPRS Module Series M85 Hardware Design 6 Mechanical Dimensions This chapter describes the mechanical dimensions of the module. 6.1.
GSM/GPRS Module Series M85 Hardware Design Figure 49: M85 Module Bottom Dimensions (Unit: mm) Figure 50: The PAD Dimensions (Unit: mm) M85_Hardware_Design Confidential / Released 75 / 88
GSM/GPRS Module Series M85 Hardware Design 6.2. Recommended Footprint Figure 51: Recommended Footprint (Unit: mm) NOTE The module should keep about 3mm away from other components in the host PCB.
GSM/GPRS Module Series M85 Hardware Design 6.3. Top View of the Module Figure 52: Top View of the Module 6.4.
GSM/GPRS Module Series M85 Hardware Design 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.
GSM/GPRS Module Series M85 Hardware Design 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].
GSM/GPRS Module Series 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. 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.
GSM/GPRS Module Series M85 Hardware Design DETAIL:A 6 PS DC圆盘44 DETAIL:A Figure 55: Tape and Reel Information Table 35: Reel Packing Model Name M85 MOQ for MP Minimum Package: 250pcs Minimum Package×4=1000pcs 250pcs Size: 370 × 350 × 56mm N.W: 0.78kg G.W: 1.54kg Size: 380 × 250 × 365mm N.W: 3.10kg G.W: 6.
GSM/GPRS Module Series M85 Hardware Design 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 GSM 07.
GSM/GPRS Module Series M85 Hardware Design [12] Quectel_GSM_EVB_User_Guide GSM EVB user guide [13] Quectel_Module_Secondary_SMT_User_Guide Module secondary SMT user guide Table 37: Terms and Abbreviations Abbreviation Description ADC Analog-to-Digital Converter AMR Adaptive Multi-Rate ARP Antenna Reference Point ASIC Application Specific Integrated Circuit BER Bit Error Rate BOM Bill Of Material BTS Base Transceiver Station CHAP Challenge Handshake Authentication Protocol CS Coding
GSM/GPRS Module Series M85 Hardware Design 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.
GSM/GPRS Module Series M85 Hardware Design 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 & Tra
GSM/GPRS Module Series M85 Hardware Design 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 Numb
GSM/GPRS Module Series M85 Hardware Design 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 Radio Block excl.USF and BCS BCS Tail Coded Bits Punctured Bits Data Rate Kb/s 40 4 456 0 9.05 268 16 4 588 132 13.4 6 312 16 4 676 220 15.6 12 428 16 - 456 - 21.
GSM/GPRS Module Series M85 Hardware Design Radio block structure of CS-4 is shown as the following figure.
GSM/GPRS Module Series M85 Hardware Design 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.
