Simcom 201607 GSM/GPRS+GPS module User Manual UDV 201607 SIM868 REV2 4

Shanghai Simcom Ltd. GSM/GPRS+GPS module UDV 201607 SIM868 REV2 4

UDV-201607 SIM868_User Manual_REV2-4

      SIM868_User Manual_REV2
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      2                                                                2016-06-20   General Notes SIMCom offers this information as a service to its customers, to support application and engineering efforts that use  the  products  designed  by  SIMCom.  The  information  provided  is  based  upon  requirements  specifically provided  to  SIMCom  by  the  customers.  SIMCom  has  not  undertaken  any  independent  search  for  additional relevant  information,  including  any  information that  may be in  the customer’s possession.  Furthermore, system validation of this product designed by SIMCom within a larger electronic system remains the responsibility of the customer or the customer’s system integrator. All specifications supplied herein are subject to change.      Copyright This document contains proprietary technical information which is the property of SIMCom Limited, copying of this  document  and  giving  it  to  others  and  the  using  or  communication  of  the  contents  thereof,  are  forbidden without express authority. Offenders are liable to the payment of damages. All rights reserved in the event of grant of a patent or the registration of a utility model or design. All specification supplied herein are subject to change without notice at any time.    Copyright © Shanghai SIMCom Wireless Solutions Ltd. 2016   Compliance Information FCC Compliance Statement: This device complies with Part 15 of the FCC Rules . Operation is subject to the following two conditions: 1. This device may not cause harmful interference, and 2. This device must accept any interference received, including interference that may cause undesired operation. This device must accept any interference received, including interference that may cause undesired operation. Product that is a radio transmitter is labeled with FCC ID. FCC Caution (1) Exposure to Radio Frequency Radiation. This equipment must be installed and operated in accordance with provided instructions and the antenna(s) used for this transmitter must be installed to provide a separation distance of at least 20 cm from all persons and must not be collocated or operating in conjunction with any other antenna or transmitter. End-users and installers must be provided with antenna installation instructions and transmitter operating conditions for satisfying RF exposure compliance. (2) Any changes or modifications not expressly approved by the grantee of this device could void the user's authority to operate the equipment. (3) This Transmitter must not be co-located or operating in conjunction with any other antenna or transmitter. (4) Changes or modifications to this unit not expressly approved by the party responsible for compliance could void the user authority to operate the equipment. (5) The modules FCC ID is not visible when installed in the host, or (6) If the host is marketed so that end users do not have straight forward commonly used methods for access to remove the module so that the FCC ID of the module is visible; then an additional permanent label referring to the enclosed module Contains Transmitter Module FCC ID: UDV-201607 or Contains UDV-201607 must be used.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      3                                                                2016-06-20 Contents Version History ........................................................................................................ 9 1. Introduction .................................................................................................... 10 2. SIM868 Overview ........................................................................................... 10 2.1. SIM868 .......................................................................................................................... 10 2.2. SIM868 Key Features ..................................................................................................... 10 2.3. Operating Mode .............................................................................................................. 13 2.4. Functional Diagram ........................................................................................................ 14 3. Package Information ...................................................................................... 15 3.1. Pin Out Diagram ............................................................................................................. 15 3.2. Pin Description ............................................................................................................... 15 3.3. Package Dimensions ....................................................................................................... 18 4. Application Interface ...................................................................................... 20 4.1. Power Supply ................................................................................................................. 20 4.1.1. Power Supply Pin ................................................................................................................................ 21 4.1.2. Monitoring Power Supply ................................................................................................................... 22 4.2. Power on/off SIM868 ..................................................................................................... 22 4.2.1. Power on SIM868 ............................................................................................................................... 22 4.2.2. Power off SIM868 ............................................................................................................................... 23 4.3. Power Saving Mode........................................................................................................ 25 4.3.1. Minimum Functionality Mode ............................................................................................................ 25 4.3.2. Sleep Mode 1 (AT+CSCLK=1) .......................................................................................................... 25 4.3.3. Wake Up SIM868 from Sleep Mode 1 ................................................................................................ 25 4.3.4. Sleep Mode 2 (AT+CSCLK=2) .......................................................................................................... 26 4.3.5. Wake Up SIM868 from Sleep Mode 2 ................................................................................................ 26 4.4. Power Saving Mode........................................................................................................ 26 4.5. Serial Port and USB Interface ......................................................................................... 27 4.5.1 Function of Serial Port ........................................................................................................................ 28 4.5.2 Serial Interfaces ................................................................................................................................... 29 4.5.3 Debug Interface ................................................................................................................................... 30 4.5.4 Software Upgrade ................................................................................................................................ 31 4.6. UART1_RI Behaviors .................................................................................................... 31 4.7. Audio Interfaces ............................................................................................................. 32 4.7.1. Speaker Interfaces Configuration ........................................................................................................ 33 4.7.2. Microphone Interfaces Configuration ................................................................................................. 34 4.7.3. Audio Electronic Characteristic .......................................................................................................... 34 4.7.4. TDD .................................................................................................................................................... 34 4.8. SIM Card Interface ......................................................................................................... 35 4.8.1. SIM Card Application ......................................................................................................................... 35
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      4                                                                2016-06-20 4.8.2. SIM Card Design Guide ...................................................................................................................... 36 4.8.3. Design Considerations for SIM Card Holder ...................................................................................... 37 4.9. SD Interface ................................................................................................................... 39 4.10. I2C Bus .......................................................................................................................... 39 4.10.1. I2C Multiplexing Function .............................................................................................................. 39 4.11. ADC ............................................................................................................................... 40 4.12. Network Status Indication............................................................................................... 40 4.13. Operating Status Indication ............................................................................................. 41 4.14. RF Synchronization Signal ............................................................................................. 41 4.14.1. RF_SYNC Multiplexing Function ................................................................................................... 42 4.15. GNSS ............................................................................................................................. 42 4.15.1. GNSS Overview .............................................................................................................................. 42 4.15.2. Power on/down GNSS ..................................................................................................................... 42 4.15.3. 1PPS Output..................................................................................................................................... 42 4.16. Antenna Interface ........................................................................................................... 42 4.16.1. GSM Antenna Interface ................................................................................................................... 43 4.16.2. GNSS Antenna Interface .................................................................................................................. 46 5. PCB Layout ..................................................................................................... 48 5.1 Pin Assignment .............................................................................................................. 48 5.2 Principle of PCB Layout ................................................................................................. 49 5.2.1 Antenna Interface ................................................................................................................................ 49 5.2.2 Power Supply ...................................................................................................................................... 49 5.2.3 SIM Card Interface .............................................................................................................................. 49 5.2.4 Audio Interface.................................................................................................................................... 49 5.2.5 Others .................................................................................................................................................. 49 6. Electrical, Reliability and Radio Characteristics .......................................... 50 6.1 Absolute Maximum Ratings ........................................................................................... 50 6.2 Recommended Operating Conditions .............................................................................. 50 6.3 Digital Interface Characteristics ...................................................................................... 50 6.4 SIM Card Interface Characteristics ................................................................................. 50 6.5 SIM_VDD Characteristics .............................................................................................. 51 6.6 VDD_EXT Characteristics ............................................................................................. 51 6.7 Current Consumption(VBAT=4.0V) .......................................................................... 51 6.8 Electro-Static Discharge ................................................................................................. 52 6.9 Radio Characteristics ...................................................................................................... 52 6.9.1 Module RF Output Power ................................................................................................................... 52 6.9.2 Module RF Receive Sensitivity ........................................................................................................... 54 6.9.3 Module Operating Frequencies ........................................................................................................... 54 7. Manufacturing ................................................................................................ 55 7.1. Top and Bottom View of SIM868 ................................................................................... 55 7.2. Typical Solder Reflow Profile ........................................................................................ 55 7.3. The Moisture Sensitivity Level ....................................................................................... 55 7.4. Baking Requirements ..................................................................................................... 56
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      5                                                                2016-06-20 8. Appendix ......................................................................................................... 57 I. Related Documents ......................................................................................................... 57 II. Multiplexing Function .................................................................................................... 58 III. Terms and Abbreviations ................................................................................................ 58 IV. Safety Caution ................................................................................................................ 60
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      6                                                                2016-06-20 Table Index TABLE 1: MODULE INFORMATION ......................................................................................................................10 TABLE 2: SIM868 KEY FEATURES .........................................................................................................................10 TABLE 3: GNSS ENGINE PERFORMANCE ............................................................................................................12 TABLE 4: CODING SCHEMES AND MAXIMUM NET DATA RATES OVER AIR INTERFACE ...........................13 TABLE 5: OVERVIEW OF OPERATING MODES....................................................................................................13 TABLE 6: PIN DESCRIPTION ..................................................................................................................................15 TABLE 7: RECOMMENDED ZENER DIODE ..........................................................................................................20 TABLE 8: THE CURRENT CONSUMPTION OF FUNCTION MODE .....................................................................25 TABLE 9: SERIAL PORT AND USB PIN DEFINITION ...........................................................................................27 TABLE 10: SERIAL PORT CHARACTERISTICS.....................................................................................................27 TABLE 11: USB_VBUS OPERATION VOLTAGE ....................................................................................................31 TABLE 12: RI BEHAVIORS......................................................................................................................................31 TABLE 13: AUDIO INTERFACE DEFINITION........................................................................................................32 TABLE 14: PERFORMANCE OF AUDIO AMPLIFIER ............................................................................................33 TABLE 15: MICROPHONE INPUT CHARACTERISTICS .......................................................................................34 TABLE 16: AUDIO OUTPUT CHARACTERISTICS ................................................................................................34 TABLE 17: SIM PIN DEFINITION ...........................................................................................................................35 TABLE 18: PIN DESCRIPTION (MOLEX SIM CARD HOLDER) ...........................................................................37 TABLE 19: PIN DESCRIPTION (AMPHENOL SIM CARD HOLDER) ....................................................................38 TABLE 20: SD MULTIPLEXING FUNCTION ..........................................................................................................39 TABLE 21: PIN DEFINITION OF THE I2C ..............................................................................................................39 TABLE 22: I2C MULTIPLEXING FUNCTION .........................................................................................................39 TABLE 23: PIN DEFINITION OF THE ADC ............................................................................................................40 TABLE 24: ADC SPECIFICATION ...........................................................................................................................40 TABLE 25: PIN DEFINITION OF THE NETLIGHT .................................................................................................40 TABLE 26: STATUS OF THE NETLIGHT PIN .........................................................................................................40 TABLE 27: NETLIGHT MULTIPLEXING FUNCTION ............................................................................................41 TABLE 28: PIN DEFINITION OF THE STATUS ......................................................................................................41 TABLE 29: DEFINITION OF THE RF_SYNC PIN ...................................................................................................41 TABLE 30: RF_SYNC MULTIPLEXING FUNCTION ..............................................................................................42 TABLE 31: RECOMMENDED TVS COMPONENT .................................................................................................46 TABLE 32: ABSOLUTE MAXIMUM RATINGS ......................................................................................................50 TABLE 33: RECOMMENDED OPERATING CONDITIONS ....................................................................................50 TABLE 34: DIGITAL INTERFACE CHARACTERISTICS ........................................................................................50 TABLE 35: SIM CARD INTERFACE CHARACTERISTICS ....................................................................................50 TABLE 36: SIM_VDD CHARACTERISTICS ...........................................................................................................51 TABLE 37: VDD_EXT CHARACTERISTICS ...........................................................................................................51 TABLE 38: CURRENT CONSUMPTION..................................................................................................................51 TABLE 39: THE ESD CHARACTERISTICS (TEMPERATURE: 25℃, HUMIDITY: 45 %) ......................................52 TABLE 40: GSM850 AND EGSM900 CONDUCTED RF OUTPUT POWER............................................................53 TABLE 41: DCS1800 AND PCS1900 CONDUCTED RF OUTPUT POWER ............................................................53 TABLE 42: CONDUCTED RF RECEIVE SENSITIVITY..........................................................................................54 TABLE 43: OPERATING FREQUENCIES ................................................................................................................54 TABLE 44: MOISTURE SENSITIVITY LEVEL AND FLOOR LIFE ........................................................................56 TABLE 45: BAKING REQUIREMENTS...................................................................................................................56 TABLE 46: RELATED DOCUMENTS ......................................................................................................................57
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      7                                                                2016-06-20 TABLE 47: MULTIPLEXING FUNCTION................................................................................................................58 TABLE 48: TERMS AND ABBREVIATIONS ...........................................................................................................58 TABLE 49: SAFETY CAUTION ...............................................................................................................................60
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      8                                                                2016-06-20 Figure Index FIGURE 1: SIM868 FUNCTIONAL DIAGRAM .......................................................................................................14 FIGURE 2: PIN OUT DIAGRAM (TOP VIEW).........................................................................................................15 FIGURE 3: DIMENSIONS OF SIM868 (UNIT: MM) ................................................................................................18 FIGURE 4: RECOMMENDED PCB FOOTPRINT OUTLINE (UNIT: MM) ..............................................................19 FIGURE 5: REFERENCE CIRCUIT OF THE VBAT/GPS_VBAT INPUT .................................................................20 FIGURE 6: REFERENCE CIRCUIT OF THE LDO POWER SUPPLY ......................................................................20 FIGURE 7: REFERENCE CIRCUIT OF THE DC-DC POWER SUPPLY ..................................................................21 FIGURE 8: VBAT VOLTAGE DROP DURING TRANSMIT BURST ........................................................................21 FIGURE 9: THE MINIMAL VBAT VOLTAGE REQUIREMENT AT VBAT DROP...................................................21 FIGURE 10: POWERED ON/DOWN MODULE USING TRANSISTOR ..................................................................22 FIGURE 11: POWERED ON/DOWN MODULE USING BUTTON ..........................................................................22 FIGURE 12: TIMING OF POWER ON MODULE.....................................................................................................22 FIGURE 13: TIMING OF POWER OFF SIM868 BY PWRKEY ................................................................................23 FIGURE 14: TIMING OF RESTART SIM868 ............................................................................................................24 FIGURE 15: RTC SUPPLY FROM CAPACITOR ......................................................................................................26 FIGURE 16: RTC SUPPLY FROM NON-CHARGEABLE BATTERY .......................................................................26 FIGURE 17: RTC SUPPLY FROM RECHARGEABLE BATTERY ...........................................................................27 FIGURE 18: CONNECTION OF THE SERIAL INTERFACES .................................................................................29 FIGURE 19: RESISTOR MATCHING CIRCUIT .......................................................................................................29 FIGURE 20 : DIODE ISOLATION CIRCUIT ............................................................................................................29 FIGURE 21: TX LEVEL MATCHING CIRCUIT .......................................................................................................30 FIGURE 22: RX LEVEL MATCHING CIRCUIT .......................................................................................................30 FIGURE 23: USB REFERENCE CIRCUIT ................................................................................................................30 FIGURE 24: CONNECTION FOR SOFTWARE UPGRADING AND DEBUGGING ................................................31 FIGURE 25: UART1_RI BEHAVIOUR OF VOICE CALLING AS A RECEIVER .....................................................32 FIGURE 26: UART1_RI BEHAVIOUR OF URC OR RECEIVE SMS .......................................................................32 FIGURE 27: UART1_RI BEHAVIOUR AS A CALLER .............................................................................................32 FIGURE 28: SPEAKER REFERENCE CIRCUIT ......................................................................................................33 FIGURE 29: MICROPHONE REFERENCE CIRCUIT ..............................................................................................34 FIGURE 30: REFERENCE CIRCUIT OF THE 8-PIN SIM CARD HOLDER ............................................................35 FIGURE 31: REFERENCE CIRCUIT OF THE 6-PIN SIM CARD HOLDER ............................................................36 FIGURE 32: MOLEX 91228 SIM CARD HOLDER ..................................................................................................37 FIGURE 33: AMPHENOL C707 10M006 512 SIM CARD HOLDER ........................................................................38 FIGURE 34: SD REFERENCE CIRCUIT ..................................................................................................................39 FIGURE 35: REFERENCE CIRCUIT OF NETLIGHT...............................................................................................41 FIGURE 36: RF_SYNC SIGNAL DURING TRANSMIT BURST .............................................................................42 FIGURE 37: GSM ANTENNA MATCHING CIRCUIT ..............................................................................................43 FIGURE 38: GSM ANTENNA MATCHING CIRCUIT WITHOUT RF CONNECTOR..............................................43 FIGURE 39: GNSS PASSIVE ANTENNA MATCHING CIRCUIT ............................................................................47 FIGURE 40: GNSS ACTIVE ANTENNA MATCHING CIRCUIT..............................................................................47 FIGURE 41: PIN ASSIGNMENT ..............................................................................................................................48 FIGURE 42: TOP AND BOTTOM VIEW OF SIM868 ...............................................................................................55 FIGURE 43: TYPICAL SOLDER REFLOW PROFILE OF LEAD-FREE PROCESS .................................................55
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      9                                                                2016-06-20 Version History Date  Version  Description of change  Author 2016-06-20 1.00  Origin  Yanwu.Wang; Xiaoxu.Chen
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      10                                                                2016-06-20 1. Introduction   This document describes SIM868 hardware interface in great detail. The document can help customer to quickly understand  SIM868 interface specifications,  electrical and  mechanical  details. With the  help  of  this document and other SIM868 application notes, customer guide, customers can use SIM868 to design various applications quickly.  2. SIM868 Overview Designed  for  global  market,  SIM868  is  integrated  with  a  high  performance  GSM/GPRS  engine  and  a  GNSS engine. SIM868 is a quad-band GSM/GPRS module that works on frequencies GSM 850MHz, EGSM 900MHz, DCS 1800MHz and PCS 1900MHz. SIM868 features GPRS multi-slot class 12/class 10 (optional) and supports the GPRS coding schemes CS-1, CS-2, CS-3 and CS-4. The GNSS solution offers best-in-class acquisition and tracing sensitivity, Time-To-First-Fix (TTFF) and accuracy.  With  a  tiny  configuration  of  17.6*15.7*2.3mm,  SIM868  can  meet  almost  all  the  space  requirements  in customers’ applications, such as smart phone, PDA and other mobile devices.  SIM868 is a SMT+LGA package with 77 pads, and provides all hardware interfaces between the module and customers’ boards.  One 3 lines serial port and one full modem serial port;  USB interface which can be used for debugging and upgrading firmware;  Audio channels which include a microphone input and two speakers output;  Programmable general purpose input and output;  Two SIM cards interface;  Support GNSS function;  SD card interface;  I2C interface;  ADC interface.  SIM868 is designed with power saving technique so that the current consumption is as low as 0.65 mA in sleep mode (with GNSS engine powered down).   SIM868 integrates TCP/IP  protocol and extended TCP/IP AT  commands which are very  useful  for data transfer applications. For details about TCP/IP applications, please refer to document [2].  2.1. SIM868 Table 1: Module Information Information  SIM868 GSM  850,900,1800 and 1900MHz GNSS  GNSS interface FLASH  32Mbit RAM  32Mbit  2.2. SIM868 Key Features Table 2: SIM868 Key Features
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      11                                                                2016-06-20 Feature  Implementation Power supply  3.4V ~4.2V Power saving  Typical power consumption in sleep mode is 0.65 mA (AT+CFUN=0 ) Frequency bands  Quad-band: GSM 850, EGSM 900, DCS 1800, PCS 1900. SIM868 can search the 4 frequency bands automatically. The frequency bands can also be set by AT command “AT+CBAND”. For details, please refer to document [1].  Compliant to GSM Phase 2/2+ Transmitting power    Class 4 (2W) at GSM 850 and EGSM 900  Class 1 (1W) at DCS 1800 and PCS 1900 GPRS connectivity  GPRS multi-slot class 12(default)  GPRS multi-slot class 1~12 (option) Temperature range  Normal operation: -40°C ~ +85°C  Storage temperature -45°C ~ +90°C Data GPRS  GPRS data downlink transfer: max. 85.6 kbps    GPRS data uplink transfer: max. 85.6 kbps      Coding scheme: CS-1, CS-2, CS-3 and CS-4  PAP protocol for PPP connect  Integrate the TCP/IP protocol.  Support Packet Broadcast Control Channel (PBCCH) USSD   Unstructured Supplementary Services Data (USSD) support SMS  MT, MO, CB, Text and PDU mode  SMS storage: SIM card SIM interface  Support SIM card: 1.8V, 3V External antenna  Antenna pad Audio features Speech codec modes:  Half Rate (ETS 06.20)  Full Rate (ETS 06.10)  Enhanced Full Rate (ETS 06.50 / 06.60 / 06.80)  Adaptive multi rate (AMR)  Echo Cancellation  Noise Suppression Serial port and   USB port Serial port:  Default one Full modem serial port  Can be used for AT commands or data stream  Support RTS/CTS hardware handshake and software ON/OFF flow control  Multiplex ability according to GSM 07.10 Multiplexer Protocol  Autobauding supports baud rate from 1200 bps to 115200bps  upgrading firmware USB port:  Can be used for debugging and upgrading firmware Phonebook management Support phonebook types: SM, FD, LD, RC, ON, MC SIM application toolkit  GSM 11.14 Release 99 Physical characteristics  Size:17.6*15.7*2.3mm  Weight:1.5g Firmware upgrade  Full modern serial port or USB interface (recommend to use USB port)
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      12                                                                2016-06-20 Table 3: GNSS engine Performance Parameter  Description  Performance Min  Type  Max  Unit Horizontal Position Accuracy(1) Autonomous    <2.5    m Velocity Accuracy(2) Without Aid    0.1    m/s DGPS    0.05    m/s Acceleration Accuracy Without Aid    0.1    m/s2 DGPS    0.05    m/s2 Timing Accuracy      10    nS Backup batter voltage V_BACKUP  2.3    4.3  V Dynamic Performance  Maximum Altitude      18000  m Maximum Velocity      515  m/s Maximum Acceleration     4  G TTFF with GPS only(3) Hot start    0.7    s Warm start    21.4    s Cold start    22.3    s TTFF with GLONASS only(3) Hot start    0.7    s Warm start    21.2    s Cold start    21.68    s TTFF with GPS and GLONASS (3) Hot start    0.6    s Warm start    21.54    s Cold start    21.67    s A-GPS TTFF(EPO in flash mode) Hot start    0.6    s Warm start    21.32    s Cold start    22.17    s Sensitivity with GPS only mode Autonomous acquisition(cold start)  -148   dBm Re-acquisition    -158    dBm Tracking    -166    dBm Sensitivity with GLONASS only mode Autonomous acquisition(cold start)  -147   dBm Re-acquisition    -155    dBm Tracking    -160    dBm Sensitivity with GPS and GLONASS   Autonomous acquisition(cold start)  -149   dBm Re-acquisition    -157    dBm Tracking    -162    dBm Receiver Channels    22/66     Update rate      5  Hz Tracking L1, CA Code        Protocol support
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      13                                                                2016-06-20 NMEA Power consumption With GPS only mode(4) Acquisition      23.4    mA Continuous tracking    22.6    mA Sleep current    650    uA Power consumption With GLONASS only mode(4) Acquisition      24    mA Continuous tracking    21    mA Sleep current    650    uA Power consumption With GPS and GLONASS (4)   Acquisition      31    mA Continuous tracking    26    mA Sleep current    650    uA (1) 50% 24hr static, -130dBm (2) 50% at 30m/s (3) GPS signal level: -130dBm (4) Single Power supply 3.8V@-130dBm,GSM IDLE Table 4: Coding schemes and maximum net data rates over air interface Coding scheme  1 timeslot  2 timeslot  4 timeslot CS-1  9.05kbps  18.1kbps  36.2kbps CS-2  13.4kbps  26.8kbps  53.6kbps CS-3  15.6kbps  31.2kbps  62.4kbps CS-4  21.4kbps  42.8kbps  85.6kbps  2.3. Operating Mode  The table below summarizes the various operating modes of SIM868. Table 5: Overview of operating modes Mode Function Normal operation GSM/GPRS SLEEP Module  will  automatically  go  into  sleep  mode  if  the  conditions  of  sleep mode are enabling and there aren’t on air and  hardware  interrupt (such as GPIO interrupt or data on serial port).   In this case, the current consumption of module will reduce to the minimal level. In sleep mode, the module can still receive paging message and SMS. GSM IDLE  Software is active. Module is registered to the GSM network, and the module is ready to communicate. GSM TALK Connection between two subscribers is in progress. In this case, the power consumption depends on network settings such as DTX off/on, FR/EFR/HR, hopping sequences, antenna. GPRS STANDBY Module is ready for GPRS data transfer, but no data is currently sent or received. In this case, power consumption depends on network settings and GPRS configuration. GPRS DATA There is GPRS data transfer (PPP or TCP or UDP) in progress. In this case,
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      14                                                                2016-06-20 power consumption is related with network settings (e.g. power control level); uplink/downlink data rates and GPRS configuration (e.g. used multi-slot settings). Power off Normal power off by sending AT command “AT+CPOWD=1” or using the PWRKEY. The power management unit shuts down the power supply for the baseband part of the module. Software  is  not  active.  The  serial  port  is  not  accessible.  Power  supply  (connected  to  3V) remains applied. Minimum functionality mode AT command “AT+CFUN” can be used to set the module to a minimum functionality mode without removing the power supply. In this mode, 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 closed, and the serial  port  is  still  accessible.  The  power  consumption  in  this  mode  is  lower  than  normal mode. 2.4. Functional Diagram The following figure shows a functional diagram of SIM868:  GSM baseband  PMU  The GSM Radio Frequency part  Antenna interface  GNSS interface  Other interface  Figure 1: SIM868 functional diagram
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      15                                                                2016-06-20 3. Package Information  3.1. Pin Out Diagram    Figure 2: Pin out Diagram (Top view) 3.2. Pin Description Table 6: Pin description Pin name  Pin number  I/O Description  Comment Power supply GPS_VBAT  34  I  Power supply for GNSS   VBAT  35  I  Power supply for GSM   VDD_EXT  40  O  2.8V power output If  these  pins  are  unused, keep open.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      16                                                                2016-06-20 GND 8,13,19,21,27,30, 31,33,36,37,45,63,66,67,69,70,71,72,73,74,75,76,77   Ground  GND for VBAT recommend to use 36,37pin Power on/down PWRKEY  39  I PWRKEY  should  be  pulled  low and  then  released  to  power on/down the module.   Internally pulled up to 3V. Audio interfaces MICP  9  I  Differential audio input If  these  pins  are  unused, keep open. MICN  10 SPK1P  11 O  Differential audio output SPK1N  12 SPK2P  44 SPK2N  43 GNSS interface GPS_RXD  62  I  Receive data If  these  pins  are  unused, keep open. GPS_TXD  61  O  Transmit data 1PPS  60  O  Time  Mark  outputs  timing  pulse related to receiver time GPS_EN  59  I  GNSS power enable VRTC  28  I/O Power supply for GNSS RTC  It  is  recommended  to connect with a battery. SD interface MCCA3  46  I/O SD serial data I/O If  these  pins  are  unused, keep open. MCCA2  47  I/O MCCA1  48  I/O MCCA0  49  I/O MCCK  50  I/O SD serial clock MCCM0  51  I/O SD command output GPIO NETLIGHT  41  O  Network status If  these  pins  are  unused, keep open. STATUS  42  O  Power on status GPIO1  57  I/O Programmable  general  purpose input and output. GPIO2  58  I/O Serial port UART1_DTR 6  I  Data terminal ready If  these  pins  are  unused, keep open. UART1_RI  7  O  Ring indicator UART1_DCD 5  O  Data carrier detect UART1_CTS 4  O  Clear to send UART1_RTS 3  I  Request to send   UART1_TXD 1  O  Transmit data
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      17                                                                2016-06-20 UART1_RXD 2  I  Receive data UART2_TXD 22  O  Transmit data UART2_RXD 23  I  Receive data Debug interface USB_VBUS  24  I Debug and download  If  these  pins  are  unused, keep open. USB_DP  25  I/O USB_DM  26  I/O ADC ADC  38  I  10bit  general  analog  to  digital converter If  these  pins  are  unused, keep open. I2C SDA  64  I/O I2C serial bus data  Internal  pulled  up  to  2.8V via 4.7KΩ SCL  65  O  I2C serial bus clock SIM card interface SIM1_VDD  18  O  Voltage  supply  for  SIM  card. Support 1.8V or 3V SIM card  All signals of SIM interface should  be  protected  against ESD  with  a  TVS  diode array. SIM1_DATA  15  I/O SIM data input/output SIM1_CLK  16  O  SIM clock SIM1_RST  17  O  SIM reset SIM1_DET  14  I  SIM card detection  If  these  pins  are  unused, keep open. SIM2_VDD  56  O  Voltage  supply  for  SIM  card. Support 1.8V or 3V SIM card  All signals of SIM interface should  be  protected  against ESD  with  a  TVS  diode array. SIM2_DATA  53  I/O SIM data input/output SIM2_CLK  54  O  SIM clock SIM2_RST  55  O  SIM reset SIM2_DET  52  I  SIM card detection  If  these  pins  are  unused, keep open. Antenna interface GSM_ANT  32  I/O Connect GSM antenna If  these  pins  are  unused, keep open. NC  20  I/O Connect Bluetooth antenna GPS_ANT  68  I  Connect GNSS antenna Synchronizing signal of RF RF_SYNC  29  O  Synchronizing signal of RF
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      18                                                                2016-06-20 3.3. Package Dimensions  Figure 3: Dimensions of SIM868 (Unit: mm)
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      19                                                                2016-06-20    Figure 4: Recommended PCB footprint outline (Unit: mm)
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      20                                                                2016-06-20 4. Application Interface  4.1. Power Supply  The power supply range of SIM868 is from 3.4V to 4.2V. Recommended voltage is 4.0V. The transmitting burst will cause voltage drop and the power supply must be able to provide sufficient current up to 2A. For the VBAT /GPS_VBAT input, a bypass capacitor (low ESR) such as a 100 µF is strongly recommended.  For  the  VBAT/GPS_VBAT  input,  a  100uF  Tantalum  capacitor  (CA  low  ESR)  and  a  1uF~10uF  Ceramics capacitor CB are strongly recommended. Increase the 33pF and 10pF capacitors can effectively eliminate the high frequency interference. A 5.1V/500mW Zener diode is strongly recommended, the diode can prevent chip from damaging by the voltage surge. These capacitors and Zener diode should be placed as close as possible to SIM868 VBAT pins.    Figure 5: Reference circuit of the VBAT/GPS_VBAT input Table 7: Recommended zener diode   Vendor  Part number  Power(watts)  Packages 1  On semi  MMSZ5231BT1G  500mW  SOD123 2  Prisemi  PZ3D4V2H  500mW  SOD323 3  Vishay  MMSZ4689-V  500mW  SOD123 4  Crownpo  CDZ55C5V1SM  500mW  0805  The following figure is the reference design of +5V input power supply. The output power supply is 4.1V, thus a linear regulator can be used.  Figure 6: Reference circuit of the LDO power supply
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      21                                                                2016-06-20 If  there  is  a high  drop-out between the input  and the  desired  output (VBAT), a DC-DC  power supply  will be preferable because of its better efficiency especially with the 2A peak current in burst mode of the module. The following figure is the reference circuit.  Figure 7: Reference circuit of the DC-DC power supply The single 3.7V Li-ion cell battery can be connected to SIM868 VBAT/GPS_VBAT pins directly. But the Ni-Cd or  Ni-MH  battery  must  be  used  carefully,  since  their  maximum  voltage  can  rise  over  the  absolute  maximum voltage of the module and damage it.  When battery  is  used,  the total impedance between  battery and  VBAT/GPS_VBAT  pins should  be less  than 150mΩ. The following figure shows the VBAT voltage drop at the maximum power transmit phase, and the test condition is as following:   VBAT=4.0V,   A VBAT bypass capacitor CA=100µF tantalum capacitor (ESR=0.7Ω), Another VBAT bypass capacitor CB=1uF~10uF.    577us 4.615msBurst:2AIVBATVBATMax:350mV Figure 8: VBAT voltage drop during transmit burst 4.1.1. Power Supply Pin  Pin34  and  Pin35  are  GPS_VBAT  and  VBAT  input;  Pin36  and  Pin37  are  GND  of  power  supply.  VDD_EXT output 2.8V when module is in normal operation mode.      When designing the power supply in customers’ application, pay special attention to power losses. Ensure that the input voltage never drops below 3.0V even when current consumption rises to 2A in the transmit burst. If the power voltage drops below 3.0V, the module may be shut down automatically. The PCB traces from the VBAT pins to the power supply  must be wide enough (at least 60mil) to  decrease voltage drops in the transmit burst. The power IC and the bypass capacitor should be placed to the module as close as possible. VBATMIN:3.0V  Figure 9: The minimal VBAT voltage requirement at VBAT drop
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      22                                                                2016-06-20 Note: Hardware power off voltage is 3.0V. 4.1.2. Monitoring Power Supply  AT command “AT+CBC” can be used to monitor the VBAT voltage. For detail, please refer to document [1].  4.2. Power on/off SIM868  4.2.1. Power on SIM868  Customer can power on SIM868 by pulling down the PWRKEY pin for at least 1 second and release. This pin is already pulled up to 3V in the module internal, so external pull up is not necessary. Reference circuits are shown as below. 4.7K47KTurn on/off impulsePWRKEY Power on/off logic100K3VModule1K Figure 10: Powered on/down module using transistor PWRKEY Power on/off logic100K3VModule1K Figure 11: Powered on/down module using button The power on timing is illustrated as in the following figure.  Figure 12: Timing of power on module
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      23                                                                2016-06-20 When power on procedure is completed, SIM868 will send following URC to indicate that the module is ready to operate at fixed baud rate. RDY This URC does not appear when autobauding function is active. Note:  Customer can use  AT  command “AT+IPR=x” to  set  a  fixed  baud rate  and  save  the configuration  to non-volatile flash  memory.  After the  configuration  is saved as fixed  baud rate, the  Code  “RDY” should be received from the serial port every time when SIM868 is powered on. For details, please refer to the chapter “AT+IPR” in document [1].  4.2.2. Power off SIM868  SIM868 will be powered off in the following situations:  Normal power off procedure: power off SIM868 by the PWRKEY pin.    Normal power off procedure: power off SIM868 by AT command “AT+CPOWD=1”.    Abnormal power off: over-voltage or under-voltage automatic power off.  Abnormal power off: over-temperature or under-temperature automatic power off.  4.2.2.1. Power off SIM868 by the PWRKEY Pin  Customer can power off SIM868 by pulling down the PWRKEY pin for at least 1 second and release. Please refer to the power on circuit. The power off timing is illustrated in the following figure.    Figure 13: Timing of power off SIM868 by PWRKEY Note: 1. the module will restart after pull down the pwrkey over 33 seconds. 2. VDD_EXT will power off after STATUS change into low level and the PWRKEY release 55ms..     If 1s<T1<2s,T2>2s; If 2s≤T1<33s,T2>T1+55ms This procedure makes the module log off from the network and allows the software to enter into a secure state to save data before completely shut down.  Before the completion of the power off procedure, the module will send URC: NORMAL POWER OFF At this moment, AT commands can’t be executed any more. Power off mode can also be indicated by STATUS pin, which is at low level at this time.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      24                                                                2016-06-20 4.2.2.2. Power off SIM868 by AT Command  SIM868 can be powered off by AT command “AT+CPOWD=1”. This procedure makes the module log off from the network and allows the software to enter into a secure state to save data before completely shut down. Before the completion of the power off procedure, the module will send URC: NORMAL POWER OFF At this moment, AT commands can’t be executed any more. Power off mode can also be indicated by STATUS pin, which is at low level at this time.  For detail about AT command “AT+CPOWD”, please refer to document [1].  4.2.2.3. Over-Temperature or Under-Temperature Power off  The module will constantly monitor the temperature of the module,   If the temperature ≥ +80℃, the following URC will be reported: +CMTE: 1 If the temperature ≤ -30℃, the following URC will be reported: +CMTE:-1 If the temperature > +85℃, the following URC will be reported, and the module will be automatically powered off. +CMTE: 2 If the temperature < -40℃, the following URC will be reported, and the module will be automatically powered off. +CMTE:-2 At this moment, AT commands can’t be executed any more. Power off mode can also be indicated by STATUS pin, which is at low level at this time.  Note:The  default  temperature  detect  is  disable,  AT  command  “AT+CMTE”  could  be  used  to  read  the temperature when the module is running.For details please refer to document [1].  4.2.2.4. Restart SIM868 by PWRKEY Pin:  When the module works normally, if the customer wants to restart the module, follow the procedure below: 1) Power off the module. 2) Wait for at least 800ms after STATUS pin changed to low level. 3) Power on the module.  Figure 14: Timing of restart SIM868
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      25                                                                2016-06-20 4.3. Power Saving Mode  SIM868  has  two  power  saving  modes:  Minimum  functionality  mode  and  sleep  mode.  AT  command “AT+CSCLK=1”can be used to set SIM868 into sleep mode. AT command “AT+CFUN=<fun>“can be used to set SIM868 into minimum functionality. When SIM868 is in sleep mode and minimum functionality mode, the current of module is lowest.  4.3.1. Minimum Functionality Mode  There are three functionality modes, which could be set by AT command “AT+CFUN=<fun>“. The command provides the choice of the functionality levels <fun>=0, 1, 4.  AT+CFUN=0:  Minimum functionality.  AT+CFUN=1:  Full functionality (default).  AT+CFUN=4:  Flight mode (disable RF function). Table 8: The current consumption of Function Mode <fun> BS-PA-MFRMS  Current consumption(mA) 0  /  0.65 1 9  0.86 5  1.02 2  1.42 4  /  0.69 Minimum  functionality  mode  minimizes  the  current  consumption  to  the  lowest  level.  If  SIM868  is  set  to minimum  functionality by  “AT+CFUN=0”,  the  RF function and  SIM  card  function  will  be  disabled.  In this case, the serial port is still accessible, but partial AT commands and correlative to RF function and SIM card function will not be accessible.    For detailed information about AT command “AT+CFUN=<fun>“, please refer to document [1].  4.3.2. Sleep Mode 1 (AT+CSCLK=1)  Customer can control SIM868 module to enter or exit the sleep mode (AT+CSCLK=1) by DTR signal. When DTR is in high level and without interrupt (on air and hardware such as GPIO interrupt or data in serial port), SIM868  will  enter  sleep  mode  automatically.  In  this  mode,  SIM868  can  still  receive  paging  or  SMS  from network but the serial port is not accessible.  4.3.3. Wake Up SIM868 from Sleep Mode 1    When SIM868 is in sleep mode 1(AT+CSCLK=1), the following methods can wake up the module:  Pull down DTR pin.         The serial port will be active after DTR pin is pulled to low level for about 50ms.  Receive a voice or data call from network.  Receive a SMS from network.  Receive external interrupt. Note: After module has received incoming call or new SMS, serial port can report URC, but the serial port can not input AT command. Only after the DTR pin is pulled to low level for 50ms, the serial port can input AT
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      26                                                                2016-06-20 command.  4.3.4. Sleep Mode 2 (AT+CSCLK=2)  In this mode, SIM868 will continuously monitor the serial port data signal. When there is no data transfer over 5 seconds on the RXD signal and there is no on air and hardware interrupts (such as GPIO interrupt), SIM868 will enter sleep mode 2 automatically. In this mode, SIM868 can still receive paging or SMS from network.  4.3.5. Wake Up SIM868 from Sleep Mode 2    When SIM868 is in sleep mode 2 (AT+CSCLK=2), the following methods can wake up the module:  Send data to SIM868 via main serial port (the first character will lose).    Receive a voice or data call from network.  Receive a SMS from network.  Note: Autobauding is default. It cannot enter sleep mode in the absence of synchronous serial port baud rate after module power on.    4.4. Power Saving Mode  Current input for GNSS RTC when the GPS_VBAT is not supplied for the GNSS power system. Current output for  backup battery when  the  GPS_VBAT  power supply  is  in  present  and the backup battery  is  in low  voltage state. The RTC power supply of GNSS can be provided by an external capacitor or a battery (non-chargeable or rechargeable) through the VRTC. The following figures show various reference circuits for RTC back up.   External capacitor backup  Figure 15: RTC supply from capacitor  Non-chargeable battery backup    Figure 16: RTC supply from non-chargeable battery
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      27                                                                2016-06-20  Rechargeable battery backup  Figure 17: RTC supply from rechargeable battery   4.5. Serial Port and USB Interface  SIM868 default provides one unbalanced asynchronous serial ports. The module is designed as a DCE (Data Communication Equipment). The following figure shows the connection between module and client (DTE). Table 9: Serial port and USB pin definition  Note: Hardware flow control is disabled by default. AT command “AT+IFC=2, 2”can enable hardware flow control. AT command “AT+IFC=0,0”can disable hardware flow control. For more details please refer to document [1]. Table 10: Serial port characteristics Symbol  Min  Max  Unit VIL  -0.3  0.7  V VIH  2.1  3.1    V VOL  -  0.4  V   Pin name  Pin number Function Serial port UART1_DTR  6  Data terminal ready UART1_RI  7  Ring indicator UART1_DCD  5  Data carrier detect UART1_CTS  4  Clear to send UART1_RTS  3  Request to send   UART1_TXD  1  Transmit data UART1_RXD  2  Receive data UART2_TXD  22  Transmit data UART2_RXD  23  Receive data GPS_TXD  61  Transmit data GPS_RXD  62  Receive data Debug port USB_VBUS  24  USB power supply USB_DP  25  D+ data input/output USB_DM  26  D- data input/output
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      28                                                                2016-06-20 VOH  2.4  -  V 4.5.1 Function of Serial Port Serial port:  Full mode device.  Contain  data lines UART1_TXD/UART1_RXD,  hardware flow control  lines  UART1_RTS/UART1_CTS, status lines UART1_DTR、UART1_DCD and UART1_RI.  Serial  port  can  be  used  for  GPRS  service  and  AT  communication.  It  can  also  be  used  for  multiplexing function. For details about multiplexing function, please refer to table 11.  Autobauding supports the following baud rates: 1200, 2400, 4800, 9600, 19200, 38400, 57600 and 115200bps  Autobauding allows SIM868 to automatically detect the baud rate of the host device. Pay more attention to the following requirements:  Synchronization between DTE and DCE: When DCE powers on with autobauding enabled, it is recommended to send "AT" or "at" or "aT" or "At" to  synchronize  the  baud  rate,  until  DTE  receives  the  "OK"  response,  which  means  DTE  and  DCE  are correctly synchronized. For more information please refer to AT command "AT+IPR".  Restrictions of autobauding operation: The DTE serial port must be set at 8 data bits, no parity and 1 stop bit. The URC such as "RDY", "+CFUN: 1" and "+CPIN: READY” will not be reported.  Note: Customer can use AT command “AT+IPR=x” to  set a fixed baud rate  and the setting will be saved to non-volatile flash memory automatically. After the configuration is set as fixed baud rate, the URC such as "RDY", "+CFUN: 1" and "+CPIN: READY” will be reported when SIM868 is powered on.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      29                                                                2016-06-20 4.5.2 Serial Interfaces The following figure shows the connection between module and client (DTE). UART1_TXDUART1_RXDUART1_RTSUART1_CTSUART1_DTRUART1_DCDUART1_RITXDRXDRTSCTSDTRDCDRINGSerial Port Serial PortModule(DCE) Customer(DTE)GND GND Figure 18: Connection of the serial interfaces If the voltage of UART is 3.3V, the following reference circuits are recommended. If the voltage is 3.0V, please change the resistors in the following figure from 5.6K to 14K. 1K5.6KRXDTXDRTSCTSGPIOGPIOEINTDTE(3.3V)5.6K5.6K1K1K1K1K1K1KModuleUART1_TXDUART1_RXDUART1_RTSUART1_CTSUART1_DTRUART1_DCDUART1_RIGND GND Figure 19: Resistor matching circuit If the voltage of UART is 3V or3.3V, the following reference circuits are recommended: UART1_TXD RXDModule DTETXDUART1_RXDVDD_EXT10K10KGND GND Figure 20 : Diode isolation circuit Note: please make sure the minimum of client high limit should be less than 2.8V minus the diode drop.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      30                                                                2016-06-20 If the voltage of UART is 5V, the following reference circuits are recommended: VDD_EXT4.7K47KUART1_TXD4.7KModuleVDD_EXTRXDVDDDTE Figure 21: TX level matching circuit VDD_EXT4.7K47K4.7KDTEUART1_RXDModuleVDD_EXTTXDVDD Figure 22: RX level matching circuit 4.5.3 Debug Interface  SIM868 could achieve software debug function through USB interface. When powering on the module, connect USB_VBUS, USB_DP, USB_DM, and GND to PC, then install the driver following the prompts, a UART port could be recognized by PC, customer could achieve the software Debug with this UART port. SIMCom recommended the following connected diagram:  MODULE USBGNDGND22RUSB_VBUS VBUS1uFUSB_DMUSB_DPUSB_DM22RUSB_DP Figure 23: USB reference circuit The TVS on USB data line should be less than 5pF, and traced by differential forms.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      31                                                                2016-06-20 Note: please reserve the USB interface or test point for the further debugging  Table 11: USB_VBUS operation voltage Pin    Min  Typ  Max  Unit USB_VBUS  4.3  5.0  7.0  V  4.5.4 Software Upgrade  Customer could upgrade module’s firmware through USB or UART interface.  If  upgrading through USB interface,  it  is  necessary to  power on SIM868 first, and  then connect  USB_VBUS, USB_DP, USB_DM, and GND to PC. There is no need to operate PWRKEY pin in the whole procedure, when SIM868 detects USB_VBUS and could communicate normally with USB_DP and USB_DM, it will enter USB download mode automatically.  If customer upgrades the software through UART interface, it is strongly recommended to lead the UART1_TXD, UART1_RXD, GND and PWRKEY pin to IO connector for the upgrading, and PWRKEY pin should connect to GND while upgrading. Refer to the following figure for debugging and upgrading software. UART1_TXDModule(DCE)UART1_RXDGNDPWRKEYTXDRXDGNDSerial PortPWRKEYI/O Connector Figure 24: Connection for software upgrading and debugging The UART interface supports the CMOS level. If customer connects the module to the computer, the level shifter should be added between the DCE and DTE.  4.6. UART1_RI Behaviors  Table 12: RI behaviors State  RI response Standby  High Voice call The pin is changed to low. When any of the following events occur, the pin will be changed to high: (1)Establish the call (2)Hang up the call SMS  The pin is changed to low, and kept low for 120ms when a SMS is received. Then it is changed to high. Others  For more details, please refer to document [2].
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      32                                                                2016-06-20    The behavior of the RI pin is shown in the following figure when the module is used as a receiver.  HIGHLOWIdle RingHang up the callEstablish the callRI Figure 25: UART1_RI behaviour of voice calling as a receiver HIGHLOWIdleRI120msReceive SMSURC  Figure 26: UART1_RI behaviour of URC or receive SMS However, if the module is used as caller, the UART1_RI will remain high. Please refer to the following figure. HIGHLOWIdle Ring Establish the callHang up the callIdleRI Figure 27: UART1_RI behaviour as a caller 4.7. Audio Interfaces  SIM868 provides an analog input (MICP; MICN), which could be used for electret microphone. The module also provides two analog outputs (SPK1P/2P; SPK1N/2N). Table 13: Audio interface definition          SPK1P/1N output can directly drive 32Ω receiver.  Pin name  Pin number  Function MICP  9  Audio input positive MICN  10  Audio input negative SPK1P  11  Audio output positive SPK1N  12  Audio output negative SPK2P  44  Audio output positive SPK2N  43  Audio output negative
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      33                                                                2016-06-20 SIM868 internal has class-AB audio amplifier, the following table is class-AB performance: Table 14: Performance of audio amplifier Test Conditions  Class-AB AMP 4.2V 8Ω THD+N=1%  0.87W 3.3V 8Ω THD+N=1%  0.53W 4.2V 8Ω THD+N=10%  1.08W 3.3V 8Ω THD+N=10%  0.65W SPK2P/2N output can directly drive 8Ω speaker.  AT command “AT+CMIC” is used to adjust the input gain level of microphone. AT command “AT+SIDET” is used to set the side-tone level. In addition, AT command “AT+CLVL” is used to adjust the output gain level. For more details, please refer to document [1].  In  order  to  improve  audio  performance,  the  following  reference  circuits  are  recommended.  The  audio  signals have to be layout according to differential signal layout rules as shown in following figures.    4.7.1. Speaker Interfaces Configuration  SPK1P/2PClose to speakerESDESD10pF33pF33pF33pFModuleSPK1N/2N10pF10pF10pF33pF33pF33pF10pF10pF Figure 28: Speaker reference circuit
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      34                                                                2016-06-20 4.7.2. Microphone Interfaces Configuration Electret MicrophoneThe lines in bold type should be accorded to differential signal layout rulesThese components should be placed to microphone as close as possibleMICPModuleMICNESDESD10pF33pF33pF33pF10pF10pF Figure 29: Microphone reference circuit 4.7.3. Audio Electronic Characteristic Table 15: Microphone input characteristics Parameter    Min  Typ  Max  Unit Microphone biasing voltage  -  1.9  2.2  V Working current  -  -  2.0  mA Input impedance(differential)  13  20  27  KΩ Idle channel noise  -  -  -67  dBm0 SINAD  Input level:-40dBm0  29  -  -  dB Input level:0dBm0  -  69  -  dB Table 16: Audio output characteristics Parameter  Conditions  Min  Typ  Max  Unit Normal output  RL=32 Ω receiver  -  15  90  mW RL=8 Ω speaker  -  -  1080  mW  4.7.4. TDD  Audio  signal could  be interferenced by RF signal. Coupling noise  could be  filtered by adding  33pF and  10pF capacitor  to  audio  lines.  33pF  capacitor  could  eliminate  noise  from  GSM850/EGSM900MHz,  while  10pF capacitor  could  eliminate  noise  from  DCS1800/PCS1900Mhz  frequency.  Customer  should  develop  this  filter solution according to field test result.  GSM antenna is the key coupling interfering source of TDD noise. Thereat, pay attention to the layout of audio lines which should be far away from RF cable, antenna and VBAT pin. The bypass capacitor for filtering should be placed near module and another group needs to be placed near to connector.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      35                                                                2016-06-20 Conducting noise is  mainly caused by the VBAT  drop.  If audio PA was powered by VBAT directly, then there will be some cheep noise from speaker output easily. So it is better to put big capacitors and ferrite beads near audio PA input.  TDD noise has something to do with GND signal. If GND plane is not good, lots of high-frequency noises will interference  microphone  and  speaker  over  bypass  capacitor.  So  a  good  GND  during  PCB  layout  could  avoid TDD noise.  4.8. SIM Card Interface  The SIM interface complies with the GSM Phase 1 specification and the new GSM Phase 2+ specification for FAST  64kbps SIM card. Both  1.8V  and 3.0V  SIM  card are  supported.  The SIM interface is  powered  from  an internal regulator in the module.  4.8.1. SIM Card Application Table 17: SIM pin definition   Pin name  Pin number Function SIM1_VDD  18  Voltage supply for SIM card. Support 1.8V or 3V SIM card SIM1_DATA  15  SIM data input/output SIM1_CLK  16  SIM clock SIM1_RST  17  SIM reset SIM1_DET  14  SIM card detection SIM2_VDD  56  Voltage supply for SIM card. Support 1.8V or 3V SIM card SIM2_DATA  53  SIM data input/output SIM2_CLK  54  SIM clock SIM2_RST  55  SIM reset SIM2_DET  52  SIM card detection It is  recommended to  use an ESD  protection component such  as  ST  (www.st.com  )  ESDA6V1-5W6 or ON SEMI (www.onsemi.com ) SMF05C. The SIM card peripheral components should be placed close to the SIM card holder. The reference circuit of the 8-pin SIM card holder is illustrated in the following figure. ModulePRESENCE100nFMOLEX-91228SIM Card22pFVCC GNDRST VPPCLK I/OGNDVDD_EXTSIM_VDDSIM_RSTSIM_CLKSIM_DATA4.7KESDA6V1SIM_DET51O51O22pF51O22pF Figure 30: Reference circuit of the 8-pin SIM card holder The SIM_DET pin is used for detection of the SIM card hot plug in. Customer can select the 8-pin SIM card
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      36                                                                2016-06-20 holder to implement SIM card detection function. AT command “AT+CSDT” is used to enable or disable SIM card detection function. For details of this AT command, please refer to document [1]. If the SIM card detection function is not used, customer can keep the SIM_DET pin open. The reference circuit of 6-pin SIM card holder is illustrated in the following figure. Module100nFMOLEX-91228C107 10M 006 51222pFVCC GNDRST VPPCLK I/OSIM_VDDSIM_RSTSIM_CLKSIM_DATAESDA6V1SIM_DET51O51O22pF51O22pF Figure 31: Reference circuit of the 6-pin SIM card holder 4.8.2. SIM Card Design Guide  SIM  card  signal  could  be  interferenced  by  some  high  frequency  signal,  it  is  strongly  recommended  to  follow these guidelines while designing:   SIM card holder should be far away from GSM antenna  SIM traces should keep away from RF lines, VBAT and high-speed signal lines  The traces should be as short as possible  Keep SIM card holder’s GND connect to main ground directly  Shielding the SIM card signal by ground well    Recommended to place a 100nF capacitor on SIM_VDD line and keep close to the SIM card holder  Add some TVS which parasitic capacitance should not exceed 50pF  Add 51Ω resistor to (SIM_RST/SIM_CLK/SIM_DATA) signal could enhance ESD protection  Add 22pf capacitors to (SIM_RST/SIM_CLK/SIM_DATA) signal to reduce RF interference
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      37                                                                2016-06-20 4.8.3. Design Considerations for SIM Card Holder  For  8  pins  SIM  card  holder,  SIMCom  recommends  to  use  Molex  91228.Customer  can  visit http://www.molex.com for more information about the holder.  Figure 32: Molex 91228 SIM card holder Table 18: Pin description (Molex SIM card holder) Pin name Signal  Description C1  SIM_VDD  SIM card power supply C2  SIM_RST  SIM card reset C3  SIM_CLK  SIM card clock C4  GND  Connect to GND C5  GND  Connect to GND C6  VPP  Not connect C7  SIM_DATA  SIM card data I/O C8  SIM_DET  Detect SIM card presence
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      38                                                                2016-06-20 For  6-pin SIM  card holder, SIMCom  recommends to  use Amphenol C707 10M006 512 .Customer  can visit http://www.amphenol.com for more information about the holder.   Figure 33: Amphenol C707 10M006 512 SIM card holder Table 19: Pin description (Amphenol SIM card holder) Pin name  Signal  Description C1  SIM_VDD  SIM card power supply C2  SIM_RST  SIM card reset C3  SIM_CLK  SIM card clock C5  GND  Connect to GND C6  VPP  Not connect C7  SIM_DATA  SIM card data I/O Note: Every time plug SIM card interval advice is greater than 2s. Otherwise may not be able to correct detection.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      39                                                                2016-06-20 4.9. SD Interface  SD interface can be configured as PCM interface; the following table shows the detailed multiplexing function. Table 20: SD multiplexing function Pin name    Pin number  Mode 0(default)  Mode 1  Mode 2  Mode 3 MCCA3  46  MCCA3  DAIPCMOUT(1.8V)  GPIO  EINT19 MCCA2  47  MCCA2  DAICLK(1.8v)  GPIO  EINT18 MCCA1  48  MCCA1  DAIPCMIN(1.8v)  GPIO  EINT17 MCCA0  49  MCCA0  DAISYNC (1.8v)  GPIO   MCCK  50  MCCK    GPIO   MCCM0  51  MCCM0    GPIO   Note: Customer can use AT command set mode. For detail, please refer to document [1]. SIM868 provides a hardware SD interface:  Figure 34: SD reference circuit If power supply is 2.8V for SD card, customer can use VDD_EXT; if power supply is 3.3V, please use external design LDO.    4.10. I2C Bus  The SIM868 provides an I2C interface which is only used in the embedded AT application. Table 21: Pin definition of the I2C Note:   1. I2C should be pulled up to 2.8V via 4.7K externally.   2. I2C function is not supported in the standard firmware. If you need, please contact SIMCom. 4.10.1. I2C Multiplexing Function Table 22: I2C multiplexing function Pin name  Pin number  Description SCL  65  I2C serial bus clock(open drain output) SDA  64  I2C serial bus data(open drain output)
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      40                                                                2016-06-20 Pin name  Pin number  Mode 0(default)  Mode 1 SCL  65  SCL  GPIO SDA  64  SDA  GPIO Note: Customer can use AT command set mode. For detail, please refer to document t[1].  4.11. ADC Table 23: Pin definition of the ADC SIM868 provides an auxiliary ADC, which can be used to measure the voltage. Customer can use AT command “AT+CADC” to read the voltage value.   Note: Customer can use AT command set mode. For detail, please refer to document t[1]. Table 24: ADC specification Parameter  Min  Typ  Max  Unit Voltage range  0  -  2.8  V ADC Resolution  -  10  -  bits RIN Input resistance Unselected channel Selected channel    400 1    M M CIN Input capacitance Unselected channel Selected channel       50 4  fF pF Sampling rate  -  -  1.08  MHz ADC precision    10  30  mV  4.12. Network Status Indication Table 25: Pin definition of the NETLIGHT  The  NETLIGHT  pin  can  be  used to  drive a  network  status  indication LED.  The status  of this  pin is listed  in following table: Table 26: Status of the NETLIGHT pin Status SIM868 behavior Off Powered off 64ms On/ 800ms Off Not registered the network 64ms On/ 3000ms Off Registered to the network 64ms On/ 300ms Off GPRS communication is established  Pin name  Pin number  Description ADC  38  Analog voltage input Pin name  Pin number  Description NETLIGHT 41 Network Status Indication
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      41                                                                2016-06-20 Reference circuit is recommended in the following figure: ModuleNETLIGHTVBAT4.7K47KR Figure 35: Reference circuit of NETLIGHT Table 27: NETLIGHT multiplexing function Pin name  Pin number  Mode 0(default)  Mode 1 NETLIGHT  41  NETLIGHT  GPIO Note: Customer can use AT command set mode. For detail, please refer to document t[1].  4.13. Operating Status Indication  The pin42 is for operating status indication of the module. The pin output is high when module is powered on, and output is low when module is powered off. Table 28: Pin definition of the STATUS Pin name  Pin number  Description STATUS  42  Operating status indication Note: For timing about STATUS, please reference to the chapter “4.2 power on/down scenarios”  4.14. RF Synchronization Signal  The synchronization signal serves to indicate growing power consumption during the transmit burst. Table 29: Definition of the RF_SYNC pin  The timing of the synchronization signal is shown  in the following  figure. High level  of the RF_SYNC signal indicates increased power consumption during transmission. Pin name  Pin number  Description RF_SYNC  29  Transmit synchronization signal
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      42                                                                2016-06-20 Transmit burstRF_SYNC577us220us Figure 36: RF_SYNC signal during transmit burst 4.14.1. RF_SYNC Multiplexing Function  RF_SYNC can also be  used as  GPIO to indicate the  RF  Jamming.  The RF_SYNC  function and  RF Jamming Detection function can be switched by AT+SJDR command. Table 30: RF_SYNC Multiplexing function Pin name  Pin number  Mode 0(default)  Mode 1 RF_SYNC  29  RF Synchronization Signal JD(RF jamming detection) Note: About AT+SJDR, please refer to document [1].  4.15. GNSS   4.15.1. GNSS Overview  SIM868  provide  a  high-performance  L1  GNSS  solution  for  cellular  handset  applications.  The  solution  offers best-in-class  acquisition  and  tracking  sensitivity,  Time-To-First-Fix  (TTFF)  and  accuracy.  The  GNSS  engine supports  both  fully-autonomous  operations  for  use  in  handheld  consumer  navigation  devices  and  other standalone navigation systems. GNSS engine Performance, please refer to Table 3.  GNSS NMEA information is output by serial port. The default baud rate is 115200bps.  4.15.2. Power on/down GNSS  The GNSS engine is controlled by GNSS_EN PIN, so when it is necessary to run GNSS,the GNSS_EN must be pulled up to 2.8V. When it is necessary to power off GNSS,the GNSS_EN must be pulled down to GND.  4.15.3. 1PPS Output  The 1PPS pin outputs  pulse-per-second (1PPS) pulse signal for precise timing  purposes. It will  come  out after successfully  positioning  .The  1PPS  signal  can  be  provided  through  designated  output  pin  for  many  external applications.    4.16. Antenna Interface  There are two antenna interfaces, GSM_ANT、GPS_ANT.  The input impendence of the two antenna should be 50Ω, and the VSWR should be less than 2.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      43                                                                2016-06-20  It is recommended that the GSM antenna should be placed as far as possible.  The isolations of the two antenna should be bigger than 30dB  The modular connection to the antenna is made through a host’s printed board microstrip trace layout,the impendence of the microstrip trace is control in 50Ω,the series connection component in the trace is 0Ω  resistors for default, the size of series connection componentcan be 0402 or 0201.the length of the microstrip trace should be as short as possible for reduce insertion loss.  4.16.1. GSM Antenna Interface  There  is  a  GSM  antenna  pad  named  GSM_ANT  to  connect  an  external  GSM  antenna,  the  connection  of  the antenna must be decoupled from DC voltage. This is necessary because the antenna connector is DC coupled to ground via an inductor for ESD protection. The external antenna must be matched properly to achieve the best performance, so the matching circuit is necessary. It is recommended to reserve the matching circuit as following:  Figure 37: GSM antenna matching circuit The  RF  connector  is  used  for  conduction  test.  If  the  space  between  RF  pin  and  antenna  is  not  enough,  the matching circuit should be designed as in the following figure:  Figure 38: GSM antenna matching circuit without RF connector In above figure, the components R101, C101 and C102 are used for antenna matching, the value of components can only be got after the antenna tuning, usually, they are provided by antenna vendor. By default, the R101 is 0Ω resistors, and the C101, C102 are reserved for tuning.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      44                                                                2016-06-20         Dipole    Antenna    Reference    PCBLayout    Requirements.   Dipole Antenna Reference Design PCB Mount these devices with brown mark facing up. Units: mm Line width should be designed to provide 50Ωimpedance matching characteristics.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      45                                                                2016-06-20
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      46                                                                2016-06-20   The RF test connector in the figure is used for the conducted RF performance test, and should be placed as close as  to  the  module’s  antenna  pin.  The  traces  impedance  between  components  must  be  controlled  in  50Ω. The component  D101  is  a  bidirectional  TVS  component,  which  is  used  for  ESD  protection,  the  recommended  part numbers of the TVS are listed in the following table: Table 31: Recommended TVS component Package  Type  Supplier 0201  LXES03AAA1-098  Murata 0201  LXES03AAA1-154  Murata 0402  LXES15AAA1-153  Murata 0402  LXES15AAA1-100  Murata 0402  LXES15AAA1-017  Murata  4.16.2. GNSS Antenna Interface  The module also provides a GNSS antenna interface named GPS_ANT to connect the antenna on the customer’s application board.    To  obtain  excellent GNSS  reception performance,  a  good  antenna will always be required. Proper choice and placement of the antenna will ensure that satellites at all elevations can be seen, and therefore, accurate  fix  measurements  are  obtained.    There  are  two  normal  options:  passive  antenna  and  active  antenna.   GNSS  antenna  choice  should  be  based  on  the  designing  product  and  other  conditions.    For  detailed  Antenna designing consideration, please refer to related antenna vendor’s design recommendation. The antenna vendor will offer  further  technical  support  and  tune  their  antenna  characteristic  to  achieve  successful  GNSS  reception performance.  SIM868 provides GSM antenna named GSM_ANT, customer could use 50Ω microstrip line or stripline antenna connect to the module. The maximum gain of the Main  antenna gain should not exceed 3dBi considering the SAR radio. No antenna gain may be used that would exceed the 2W EIRP power limit in 1900MHz band。
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      47                                                                2016-06-20 It  have  according  to  reference  trace  and  matching  circuit  testing  all  FCC  items,and   all  items  satisfy  FCC requirements.Only  the  reference  trace  and  matching circuit  is  certified,  antenna  design  must  refer  to  it,  any other  deviations  require  testing  Class  II  applications  as  required  by  FCC.    The  certified  matching  circuit  as following:   The external antenna must be matched properly to achieve best performance, so the matching circuit is necessary, the connection is recommended as the following figure:  Figure 39: GNSS passive antenna matching circuit  The  components  R101,  C101 and  C102 are  used for antenna  matching,  the components’  value only can be  got after the antenna tuning. Normally R101 is 0Ω, C101 and C102 are not mounted.   Figure 40: GNSS active antenna matching circuit  Active antennas have an integrated Low-Noise Amplifier (LNA). VCC_ANT is needed on customer’s application board  for the  active antenna power input, as  shown in  Figure  40.  The inductor  L101 is used  to  prevent  the RF signal from leaking into the VCC_ANT pass and route the bias supply to the active antenna, the recommended value of L101 is no less than 27nH.    R102 can protect the whole circuit in case the active antenna is shorted to ground.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      48                                                                2016-06-20 5. PCB Layout This section will give some guidelines on PCB layout, in order to eliminate interfere or noise.  5.1 Pin Assignment  Before  PCB  layout,  we  should  learn  about  pin  assignment  in  order  to  get  reasonable  layout  with  so  many external components. Following figure is the overview of pin assignment of the module.  Figure 41: PIN assignment
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      49                                                                2016-06-20 5.2 Principle of PCB Layout  During  layout,  attention  should  be  paid  to  the  following  interfaces,  like  Antenna,  power  supply,  SIM  card interface, audio interface, and so on.  5.2.1 Antenna Interface   The length of trace between pin output and connector should be as short as possible;  Do not trace RF signal over across the board;    The RF signal should be far away from SIM card, power ICs.  5.2.2 Power Supply   VBAT and return GND are very important in layout;    The positive line of VBAT should be as short and wide as possible;  The correct flow from source to VBAT pin should go though Zener diode then huge capacitor;  Pin 36 and Pin37 are GND signals, and shortest layout to GND of power source should be designed;  There are 23 GND pads in the module; these pads could enhance the GND performances. On the upper layer of these pads, do not trace any signal if possible.  5.2.3 SIM Card Interface   SIM card holder has no anti-EMI component inside. Thus SIM card interface maybe interfered, please pay more attention on this interface during layout;    Ensure SIM card holder is far way from antenna or RF cable inside;  Put SIM card holder near the module, as nearer as possible;    Add ESD component to protect SIM_CLK, SIM_DATA, SIM_RST and SIM_VDD signals which should be far away from power and high-speed-frequency signal.  5.2.4 Audio Interface   The signal trace of audio should far away from antenna and power;    The audio signal should avoid to parallel with VBAT trace.  5.2.5 Others   It is better to trace signal lines of UART bunched, as well as signals of USB.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      50                                                                2016-06-20 6. Electrical, Reliability and Radio Characteristics  6.1 Absolute Maximum Ratings  The  absolute  maximum  ratings  stated  in  following  table  are  stress  ratings  under  non-operating  conditions. Stresses beyond any of these limits will cause permanent damage to SIM868.   Table 32: Absolute maximum ratings Symbol  Min  Typ  Max  Unit VBAT  -  -  4.5  V Current    0  -  2.0  A USB_VBUS  -  -  7  V II*  -  4  16  mA IO*  -  4  16  mA These parameters are for digital interface pins, GPIO, and UART.  6.2 Recommended Operating Conditions Table 33: Recommended operating conditions Symbol  Parameter  Min  Typ  Max  Unit VBAT  Power supply voltage  3.4  4.0  4.4  V TOPER  Operating temperature  -40  +25  +85  ℃ TSTG  Storage temperature  -45    +90  ℃  6.3 Digital Interface Characteristics Table 34: Digital interface characteristics Symbol  Parameter  Min  Typ  Max  Unit VIH  High-level input voltage  2.1  -  3.1  V VIL  Low-level input voltage  -0.3  -  0.7  V VOH  High-level output voltage  2.4  -  -  V VOL  Low-level output voltage  -  -  0.4  V Note: These parameters are for digital interface pins, such as keypad, GPIO and UART.  6.4 SIM Card Interface Characteristics Table 35: SIM card interface characteristics Symbol  Parameter  Min  Typ  Max  Unit IIH  High-level input current  -1.0  -  1.0  uA IIL  Low-level input current  -1.0  -  1.0  uA
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      51                                                                2016-06-20 VIH  High-level input voltage  1.4  -  -  V 2.4  -  -  V VIL  Low-level input voltage  -  -  0.27  V     0.4  V VOH  High-level output voltage  1.62  -  -  V 2.7  -  -  V VOL  Low-level output voltage  -  -  0.36  V -  -  0.4  V  6.5 SIM_VDD Characteristics Table 36: SIM_VDD characteristics Symbol  Parameter  Min  Typ  Max  Unit VO  Output voltage  -  3.0  -  V -  1.8  - IO  Output current  -  -  10  mA  6.6 VDD_EXT Characteristics Table 37: VDD_EXT characteristics Symbol  Parameter  Min  Typ  Max  Unit VO  Output voltage  2.7  2.8  2.9  V IO  Output current  -  -  50  mA  6.7       Current Consumption(VBAT=4.0V) Table 38: Current consumption Symbol Parameter  Conditions  Min    Typ  Max  Unit VBAT Voltage      4.0    V Power drop  PCL=5      350  mV Voltage ripple PCL=5 @ f<200kHz @ f>200kHzss                                                                                                                                 50                       2.0  mV mV IVBAT  Average current Power off mode    130  150  uA     Sleep mode (AT+CFUN=1): ( BS-PA-MFRMS=9 ) ( BS-PA-MFRMS=5) ( BS-PA-MFRMS=2)    0.86 1.02 1.42    mA mA mA Idle mode (AT+CFUN=1): GSM850 EGSM900 DCS1800    13.7 13.7 13.7    mA mA mA
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      52                                                                2016-06-20 PCS1900  13.7  mA Voice call (PCL=5): GSM850 EGSM900 Voice call (PCL=0): DCS1800 PCS1900    223 234  162 170    mA mA  mA mA Data mode GPRS (1Rx,4Tx): GSM850 EGSM900 DCS1800 PCS1900    378 414 270 308    mA mA mA mA Data mode GPRS (3Rx,2Tx): GSM850 EGSM900 DCS1800 PCS1900    323 340 212 236    mA mA mA mA Data mode GPRS (4Rx,1Tx): GSM850 EGSM900 DCS1800 PCS1900    217 223 153 163    mA mA mA mA IMAX  Peak current  During Tx burst      2.0  A Note: In above table the current consumption value is the typical one of the module tested in laboratory. In the mass production stage, there may be differences among each individual.  6.8   Electro-Static Discharge  SIM868 is an ESD sensitive component, so attention should be paid to the procedure of handling and packaging. The ESD test results are shown in the following table.   Table 39: The ESD characteristics (Temperature: 25℃, Humidity: 45 %) Pin name  Contact discharge  Air discharge VBAT  ±5KV  ±10KV GND  ±5KV  ±10KV UART1_TXD /UART1_RXD  ±4KV  ±8KV Antenna port  ±5KV  ±10KV SPKP/SPKN/MICP/MICN  ±4KV  ±8KV PWRKEY  ±4KV  ±8KV  6.9 Radio Characteristics 6.9.1 Module RF Output Power The following table shows the module conducted output power, it is followed by the 3GPP TS 05.05 technical
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      53                                                                2016-06-20 specification requirement. Table 40: GSM850 and EGSM900 conducted RF output power GSM850,EGSM900 PCL  Nominal output power (dBm)  Tolerance (dB) for conditions Normal  Extreme 5  33  ±2  ±2.5 6  31  ±3  ±4 7  29  ±3  ±4 8  27  ±3  ±4 9  25  ±3  ±4 10  23  ±3  ±4 11  21  ±3  ±4 12  19  ±3  ±4 13  17  ±3  ±4 14  15  ±3  ±4 15  13  ±3  ±4 16  11  ±5  ±6 17  9  ±5  ±6 18  7  ±5  ±6 19-31  5  ±5  ±6  Table 41: DCS1800 and PCS1900 conducted RF output power DCS1800,PCS1900 PCL  Nominal output power (dBm)  Tolerance (dB) for conditions Normal  Extreme 0  30  ±2  ±2.5 1  28  ±3  ±4 2  26  ±3  ±4 3  24  ±3  ±4 4  22  ±3  ±4 5  20  ±3  ±4 6  18  ±3  ±4 7  16  ±3  ±4 8  14  ±3  ±4 9  12  ±4  ±5 10  10  ±4  ±5 11  8  ±4  ±5 12  6  ±4  ±5 13  4  ±4  ±5
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      54                                                                2016-06-20 14  2  ±5  ±6 15  0  ±5  ±6 For the module’s output power, the following should be noted:    At GSM900 and GSM850 band, the module is a class 4 device, so the module’s output power should not exceed 33dBm,  and  at  the  maximum  power  level,  the  output  power tolerance should  not  exceed +/-2dB  under normal condition and +/-2.5dB under extreme condition.  At DCS1800 and PCS1900 band, the module is a class 1 device, so the module’s output power should not exceed 30dBm, and at the maximum  power level, the output power  tolerance should  not exceed  +/-2dB under normal  condition and +/-2.5dB under  extreme condition. 6.9.2 Module RF Receive Sensitivity The following table shows the module’s conducted receiving sensitivity, it is tested under static condition. Table 42: Conducted RF receive sensitivity Frequency    Receive sensitivity(Typical) Receive sensitivity(Max) GSM850,EGSM900  < -109dBm  < -107dBm DCS1800,PCS1900  < -109dBm  < -107dBm 6.9.3 Module Operating Frequencies The  following  table  shows  the  module’s  operating  frequency  range;  it  is  followed  by  the  3GPP  TS  05.05 technical specification requirement. Table 43: Operating frequencies Frequency    Receive    Transmit   GSM850  869    ~  894MHz  824    ~  849MHz EGSM900  925    ~  960MHz  880    ~  915MHz DCS1800  1805  ~  1880MHz  1710  ~  1785MHz PCS1900  1930  ~  1990MHz  1850  ~  1910MHz
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      55                                                                2016-06-20 7. Manufacturing 7.1. Top and Bottom View of SIM868     Figure 42: Top and bottom view of SIM868 7.2. Typical Solder Reflow Profile   Figure 43: Typical solder reflow profile of lead-free process  7.3. The Moisture Sensitivity Level  The  moisture sensitivity level  of SIM868 module is 3. The modules should be mounted within 168 hours after unpacking  in  the  environmental  conditions  of  temperature  <30℃  and  relative  humidity  of  <60%  (RH).  It  is necessary to bake the module if the above conditions are not met:
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      56                                                                2016-06-20 Table 44: Moisture sensitivity level and floor life Moisture  Sensitivity  Level (MSL) Floor Life (out of bag) at factory ambient≤30°C/60% RH or as stated 1  Unlimited at  ≦30℃/85% RH 2  1 year 2a  4 weeks 3  168 hours 4  72 hours 5  48 hours 5a  24 hours 6  Mandatory bake before use. After bake, it must be reflowed within the time limit specified on the label. NOTES: 1.  If  the  vacuum  package  is  not  open  for  3  months  or  longer  than  the  packing  date,  baking  is  also recommended before re-flow soldering. 2. For product handling, storage, processing, IPC / JEDEC J-STD-033 must be followed.  7.4. Baking Requirements  SIM868 modules are vacuum packaged, and guaranteed for 6 months storage without opening or leakage under the following conditions: the environment temperature is lower than 40℃, and the air humidity is less than 90%.  If the condition meets one of the following ones shown below, the modules should be baked sufficiently before re-flow soldering, and the baking condition is shown in below table; otherwise the module will be at the risk of permanent damage during re-flow soldering.   If the vacuum package is broken or leakage;  If the vacuum package is opened after 6 months since it’s been packed;  If the vacuum package is opened within 6 months but out of its Floor Life at factory ambient≦30℃/60%RH or as stated.  Table 45: Baking requirements Baking temperature  Moisture  Time   40℃±5℃  <5%  192 hours 120℃±5℃  <5%  4 hours Note:  Care  should  be  taken  if  that  plastic  tray  is  not  heat-resistant,  the  modules  should  be  taken  out  for preheating, otherwise the tray may be damaged by high-temperature heating.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      57                                                                2016-06-20 8. Appendix I. Related Documents Table 46: Related documents SN  Document name  Remark [1]  SIM800_Series_AT_Command_Manual   [2]  SIM800  Series  Port Application Note_V1 02.doc   [3]  ITU-T  Draft  new recommendation V.25ter: Serial asynchronous automatic dialing and control [4]  GSM 07.07: Digital cellular telecommunications (Phase 2+); AT command set for GSM Mobile Equipment (ME) [5]  GSM 07.10:  Support GSM 07.10 multiplexing protocol   [6]  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) [7]  GSM 11.14: Digital  cellular  telecommunications  system  (Phase  2+); Specification  of  the  SIM  Application  Toolkit  for  the  Subscriber Identity Module – Mobile Equipment (SIM – ME) interface [8]  GSM 11.11: Digital  cellular  telecommunications  system  (Phase  2+); Specification  of  the  Subscriber  Identity  Module  –  Mobile Equipment (SIM – ME) interface [9]  GSM 03.38: Digital  cellular  telecommunications  system  (Phase  2+);  Alphabets and language-specific information [10]  GSM 11.10 Digital  cellular  telecommunications  system  (Phase  2);    Mobile Station  (MS)  conformance  specification;  Part  1:  Conformance specification [11]  AN_Serial Port  AN_Serial Port [12]  SIM868_GNSS_Application Note
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      58                                                                2016-06-20 II. Multiplexing Function Table 47: Multiplexing function Pin name  Reset Pin number Mode 0(default) Mode 1  Mode 2 Mode 3 SIM1_DET  I/PD  14  SIM1_DET  GPIO  EINT14  SIM2_DET  I/PD  52  SIM2_DET  GPIO  EINT16  NETLIGHT  I/PD  41  NETLIGHT  GPIO  UTXD   UART1_DTR I/PD  6  UART1_DTR  GPIO  EINT13  UART1_RI  I/PD  7  UART1_RI  GPIO  EINT11  UART1_DCD I/PD  5  UART1_DCD  GPIO  URXD   UART1_CTS I/PD  4  UART1_CTS  GPIO  EINT12  UART1_RTS I/PD  3  UART1_RTS  GPIO     MCCA3  I/PD  46  MCCA3  DAIPCMOUT(1.8V) GPIO  EINT19 MCCA2  I/PD  47  MCCA2  DAICLK(1.8v)  GPIO  EINT18 MCCA1  I/PD  48  MCCA1  DAIPCMIN(1.8v)  GPIO  EINT17 MCCA0  I/PD  49  MCCA0  DAISYNC (1.8v)  GPIO   MCCK  I/PD  50  MCCK    GPIO   MCCM0  I/PD  51  MCCM0    GPIO   Note: Multiplexing function need different software supply.  III. Terms and Abbreviations Table 48: Terms and abbreviations Abbreviation    Description ADC   Analog-to-Digital Converter AMR  Adaptive Multi-Rate CS    Coding Scheme CTS    Clear to Send DTE    Data Terminal Equipment (typically computer, terminal, printer) DTR    Data Terminal Ready DTX    Discontinuous Transmission EFR    Enhanced Full Rate EGSM    Enhanced GSM ESD    Electrostatic Discharge ETS    European Telecommunication Standard FR    Full Rate GPRS    General Packet Radio Service GSM    Global Standard for Mobile Communications HR    Half Rate MO    Mobile Originated MS    Mobile Station (GSM engine), also referred to as TE MT    Mobile Terminated
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      59                                                                2016-06-20 PAP    Password Authentication Protocol PBCCH    Packet Broadcast Control Channel PCB    Printed Circuit Board PCL  Power Control Level PCS    Personal Communication System, also referred to as GSM 1900 PDU    Protocol Data Unit PPP    Point-to-point protocol RF    Radio Frequency RMS    Root Mean Square (value) RX    Receive Direction SIM    Subscriber Identification Module SMS    Short Message Service TE    Terminal Equipment, also referred to as DTE TX    Transmit Direction SINAD  Signal to Noise and Distortion Ratio UART  Universal Asynchronous Receiver & Transmitter URC    Unsolicited Result Code USSD    Unstructured Supplementary Service Data Phonebook abbreviations FD  SIM fix dialing phonebook LD    SIM last dialing phonebook (list of numbers most recently dialed) MC    Mobile Equipment list of unanswered MT calls (missed calls) ON  SIM (or ME) own numbers (MSISDNs) list RC    Mobile Equipment list of received calls SM    SIM phonebook NC  Not connect
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      60                                                                2016-06-20 IV. Safety Caution  Table 49: Safety caution Marks  Requirements  When in a hospital or other health care facility, observe the restrictions about the use of mobiles. Switch  the  cellular  terminal  or  mobile  off,  medical  equipment  may  be  sensitive  to  not  operate normally for RF energy interference.  Switch off the cellular terminal or mobile before boarding an aircraft. Make sure it is switched off. The  operation  of  wireless  appliances  in  an  aircraft  is  forbidden  to  prevent  interference  with communication systems. Forget to think much of these instructions may lead to the flight safety or offend against local legal action, or both.  Do not operate the cellular terminal or mobile in the presence of flammable gases or fumes. Switch off the cellular terminal when you are  near petrol stations, fuel depots, chemical plants or where blasting operations are in progress. Operation of any electrical equipment in potentially explosive atmospheres can constitute a safety hazard.  Your cellular terminal or mobile receives and transmits radio frequency energy while switched on. RF  interference  can  occur  if  it  is  used  close  to  TV  sets,  radios,  computers  or  other  electric equipment.  Road  safety  comes  first!  Do  not  use  a  hand-held  cellular  terminal  or  mobile  when  driving  a vehicle, unless it is securely mounted in a holder  for hands  free  operation. Before  making a call with a hand-held terminal or mobile, park the vehicle.  GSM cellular terminals or mobiles operate over radio frequency signals and cellular networks and cannot be guaranteed to connect in all conditions, for example no mobile fee or a invalid SIM card. While you are in this condition and need emergent help, please remember using emergency calls. In  order  to  make  or  receive  calls,  the  cellular  terminal  or  mobile  must  be  switched  on  and  in  a service area with adequate cellular signal strength. Some networks do not allow for emergency call if certain network services or phone features are in use (e.g. lock functions, fixed dialing etc.). You may have to deactivate those features before you can make an emergency call. Also, some networks require that a valid SIM card be properly inserted in the cellular terminal or mobile.
                                                                      Smart Machine Smart Decision SIM868_Hardware_Design_V1.00                      61                                                                2016-06-20 Contact us: Shanghai SIMCom Wireless Solutions Co.,Ltd. Address: Building A, SIM Technology Building, No. 633, Jinzhong Road, Shanghai, P. R. China 200335 Tel: +86 21 3252 3300 Fax: +86 21 3252 3020 URL: www.sim.com/wm

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