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SIM908-C_Hardware Design_V1.01

1. 39 5 GPS Application Interface eese eese eene N 41 2 GPS Operating MOUS ERE P LES WIS d 41 5 2 Power on down 5 8 41 5 2 1 Power on GPS engine pp 41 5 22 Power down GPS 42 5 3 GPS VCC RF and GPS VAN We 42 5 4 GPS Antenna In nterl qge 42 5 4 1 GPS Antenna aene denne 42 5 4 2 GPS Antenna Choice Consideration RN 43 6 Electrical Reliability and Radio Characteristics 44 6 1 Absolute Maximum 1 20 11 20 00 1 nest rere 44 6 2 Recommended Operating Conditions e a 44 6 3 Digital Interface Characteristics UULLL GA u 44 6 4
2. 32 FIGURE 28 EARPHONE REFERENKE CIRCUIT ten 32 FIGURE 29 REFERENCE CIRCUIT OF THE 8 PIN SIM CARD HOLDER ene 34 FIGURE 30 REFERENCE CIRCUIT OF THE 6 PIN SIM CARD eee 34 FIGURE 31 AMPHENOL 707 10 006 5122 SIM CARD eene nennen een eren 35 FIGURE 32 MOLEX 91228 SIM CARD HOLDER eene tenni nonton nno tetro intanto 36 FIGURE 33 RFBEHAVIOUR OF VOICE CALLING AS A eene eene enne 37 FIGURE 34 RI BEHAVIOUR OF DATA CALLING AS A RECEIVER eee eee enne enne 38 FIGURE 35 RI BEHAVIOUR OF URC OR RECEIVE 5 85 38 FIGURE 36 RI BEHAVIOUR AS A CALDER eres sete tne retento ttt petuo soie 38 FIGURE 37 REFERENCE CIRCUIT OF NETLIGHT eese nennen nennen eerte nnne 39 FIGURE 38 THE RF INTERFACE OF 770707 3 40 FIGURE 39 GSM ANTENNA MATCHING CIRCUIT 40 FIGURE 40 GPS ANTENNA MATCHING 42 FIGURE 41 TOP VIEW OF SIM908 C 49 SIM908 C_Hardware Design_V1 01 6 2011 09 09 ersion Histor Smart Machine Smart Decision 1 Introduction This document describes SIM908 C hardware interface in great detail This document can help user to quickly under
3. of SIM Tech SIM908 C Hardware Design V1 01 Smart Machine Smart Decision Document Title SIM908 C Hardware Design Version 1 01 Date 2011 09 09 Status Release Document Control ID SIM908 C_Hardware Design V1 01 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 the contents thereof are forbidden without express authority Offenders are liable to the payment of damages rights reserved in the event of grant of a patent or the registration of a utility model or design specification supplied herein are subject to change without notice at any time Copyright Shanghai SIMCom W
4. u aaa 26 445 a 27 4 5 RUC Backup ETE 27 4 6 Seal Ugutio N E E E E E 29 4 6 1 Function of Serial Port and Debug 29 462 Software Upgrade and ERE NIE ENS 30 4 7 Audio ICEL ACES onte teilen 31 4 7 1 Speaker Interface Configuration pe 31 4 7 2 Microphone Interfaces Configuration 32 4 7 3 Earphone Interface 32 SIM908 C_Hardware Design_V1 01 3 2011 09 09 B Smart Machine Smart Decision 4 74 Audio Electronic 33 4 8 SUMUGaidJnteriaee uuu ususi sasa sas 33 481 SIM Card Applications en enano ho 33 482 Design Considerations for SIM Card 1 1 200202 001 400 00000 enne 34 4 9 LCD Display ySPI Interia Ce 36 TIO 37 4 11 OBIECIT 37 412 Network Status Indication et 38 4 13 General Purpose Input Output GPIO 0 999599995999 5909959594955999 5999 5999 59999599995 39 BUZZER 39 415 GSM Antenna
5. chargeable Battery Figure 19 RTC supply from non chargeable battery Rechargeable battery backup MODULE VRIC 10K RTC Rechargeable i Backup Battery 12 Figure 20 RTC supply from rechargeable battery Coin type rechargeable 15 recommended such as XH414H IVO1E form Seiko can be used Typical charge discharge curves for this battery are shown in the following figure Charge Discharge Characteristics 3 5 T T T T i i 3 0 4 4 2 5 N 5 2 25 2555 gt 20 2 4 icem S 1651 Am Charge 3 3V 50uA Shr RT CC CV 5 Discharge 20uA cov 10 w 1 1 05 14 4 0 0 0 20 40 60 80 100 Capacity SIM908 C_Hardware Design_V1 01 28 2011 09 09 Smart Machine Smart Decision Figure 21 Seiko 414 01 Charge Discharge Characteristic 4 6 Serial Interfaces SIM908 C provides two unbalanced asynchronous serial ports One 15 the serial port and the other is the debug port The module is designed as a DCE Data Communication Equipment The following figure shows the connection between module and client DTE If only and TXD are u
6. om E ven e vsar ano ono es vr 7 s vear qo VLVd WIS WIS XN 849 154 WIS XL 549 Figure 2 SIM908 C pin out diagram BOTTOM view SIM908 C Hardware Design V1 01 12 2011 09 09 ez Smart Machine Smart Decision 32 Pin Description Table 5 Pin description VBAT 2 4 6 8 1 Power supply 3 2V 4 8 It is recommended to VRTC 11 10 Power supply for RTC connect with a battery or a capacitor e g 4 7uF GPS_VCC_ RF 56 O 2 8V output for GPS active antenna If it is unused keep open GPS_VANT 58 I GPS active antenna power supply If it is unused keep open GND 1 3 5 7 39 40 Ground VCHG 10 12 I Charger input TEMP BAT 14 Battery temperature sensor PWRKEY should be pulled low at PWRKEY 13 I least 1 second and then released to Pulled up internally power on down the module MICIP 42 d I Differential audio input MICIN 44 SPKIP 41 Differential audio output SPKIN 43 If these pins are unused MIC2P 46 EL keep open I Differential audio input MIC2N 48 SPK2P 45 0 Differential audio output SPK2N 47 STATUS 20 Power on status If these pins are unused NETLIGHT 16 0 Network status keep open DISP_CLK 26 0 DISP DATA 28 N If these pins are unused Display interface DISP D C 30 0 DISP CS 24 O GPIOO 34 lO GPIOO If these pins are unused GPIOI 22 GPIOI keep open
7. please refer to document 1 Table 6 The Current consumption of Minimum Functionality Mode fun Current consumption uA sleep mode 0 651 1 1500 4 715 4 3 3 Sleep Mode 1 1 User control SIM908 C module to enter exit sleep mode 1 AT CSCLK 1 signal When is in high level and without interrupt on air and hardware such as interrupt or data in serial port SIM908 C will enter sleep mode automatically In this mode SIM908 C can still receive paging or SMS from network but the serial port is not accessible Note For SIM908 C it requests to set AT command AT CSCLK 1 and ensure DTR at high level to enable the sleep mode 1 the default value is 0 which can not make the module to enter sleep mode For more details please refer to document 1 4 3 3 Wake Up SIM908 C from Sleep Mode 1 AT CSCLK 1 When SIM908 C 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 SIM908 C Hardware Design V1 01 23 2011 09 09 Smart Machine Smart Decision 4 34 Sleep Mode 2 AT CSCLK 2 In this mode SIM908 C 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
8. SIM908 C Hardware Design V1 01 13 2011 09 09 Smart Machine Smart Decision SIM908 C Hardware Design_V1 01 14 2011 09 09 3 3 Package Dimensions P inii E Smart Machine Smart Decision Eii 8 8 8 8 8 8 8 888888 nau UU UH UU gt Figure 3 Dimensions of SIM908 C Unit mm 3 4 Board to board connector ASTRON Company s1491060 09T R and 1590060 09T R are recommended as the board to board connector These high density SMT connectors are designed for parallel PCB to PCB applications SIM908 C_Hardware Design_V1 01 2011 09 09 Smart Machine Smart Decision 3 4 1 Mechanical dimensions of the ASTRON 1590060 09T R 2 0111 70 0 00 2 26 33 45 31 75 agaigai zas iow 419271762126 21071 39 37 L2 08 10 59 8 69 2533 42 34 40 64 A Moa dii ieii iLa 2 10 13 13 11 43 2 35 44 88 43 18 FORE ERT 5 0040 2
9. 5 4 2 GPS Antenna Choice Consideration To obtain excellent GPS reception performance a good antenna will always be required The antenna is the most critical item for successful GPS reception in a weak signal environment Proper choice and placement of the antenna will ensure that satellites at all elevations can be seen and therefore accurate fix measurements are obtained Most customers contract with antenna design houses to properly measure the radiation pattern of the final mounted configuration in a plastic housing with associated components near the antenna Linear antennas are becoming more popular and the gain is reasonable since a smaller ground plane can be used User can consider following factors as Choose a linear antenna with a reasonably uniform hemispherical gain pattern of gt 4dBi Use of an antenna with lower gain then this will give less than desirable results Please note that a RHCP antenna with a gain of 3dBi equates to a linear polarized antenna of OdBi Proper ground plane sizing is a critical consideration for small GPS antennas Proper placement of the GPS antenna should always be the FIRST consideration in designing with SIM908 If the customer s design will allow for a ceramic RHCP patch antenna with an appropriately sized ground plane and the patch is normally oriented towards the sky then that particular solution usually works the best Note that if the patch antenna ground plane is le
10. Smart Machine Smart Decision N PWRKEY Power on down logic ESD ANTI MODULE Figure 13 Powered on down module using button The power on scenarios is illustrated as following figure Tpulldown gt 1S Tdelay gt 2 25 VBAT gt PWRKEY Input Vou 2 7V STATUS Output Undefined P Active Figure 14 Timing of power on module When power on procedure is completed SIM908 C 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 User can use AT command 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 should be received from the serial port every time when SIM908 C is powered on For details please refer to the chapter AT IPR in document 1 4 2 1 2 Turn on the SIM908 C using the VCHG signal The SIM908 C will be automatically turned on when a charger is connected to the switched off SIM908 C of which VBAT pin voltage is greater than 3 2V SIM908 C will go into the Charge only Mode In this mode the module does not register to the network and has only a few AT commands available When module is powered on using the VCHG si
11. T E F 9 500 Z 24 Vo 620 138100 Figure 6 U FL R SMT Unit mm Pius P N 20278 0 20351 1 37 4 0 4 1 20278 18 08 13 32 Plus 4 73 0 4 at 20278 18 18 4750 4 at 4 g6 2 5 MAX at 20278 18 08 13 32 2 5 at 20351 18 37 2 7 at 20278 1R 18 P N 203017 1R 08 _ 3 8 20 3 Plug im ku Receptacle Figure 7 U FL series RF adapter cable Unit mm SIM908 C_Hardware Design_V1 01 17 2011 09 09 Smart Machine Smart Decision 4 GSM Application Interface 41 Power Supply The power supply range of SIM908 C is from 3 2V to 4 8V The transmitting burst will cause voltage drop and the power supply must be able to provide sufficient current up to 2A For the VBAT input a bypass capacitor low ESR such as a 100 is strongly recommended this capacitor should be placed as close as possible to SIM908 C VBAT pins The following figure is reference design of 5V input power supply The designed output for the power supply is 4 1V thus a linear regulator can be used DC INPUT U101 MIC29302 FB101 VBAT 270 OHM C101 100uF C103 C104 330 100nF Figure 8 Reference circuit of the LDO power supply If there is a high drop out between input and the de
12. 500 To suit the physical design of individual applications SIM908 C provides a GSM antenna connector as the following figure shows The customer s antenna also can be located in the customer s main board and connect to module s antenna connector through RF cable and RF trace which impendence must be controlled in 500 To facilitate the antenna tuning and certification test a RF connector and an antenna matching circuit should be added The following figure is the recommended circuit GSM900 lt 1dB DCS1800 1 5dB SIM908 C Hardware Design V1 01 39 2011 09 09 Smart Machine Smart Decision GSM GPS Antenna Antenna connector connector 52 1047 20 01 SN P10611331427953 IMEI 861001000004024 0678 Figure 38 RF interface of module To facilitate the antenna tuning and certification test RF connector and an antenna matching circuit should be added The following figure is the recommended circuit MODULE GND RF test connector 4 MELLE Matching circuit Antenna feed pad GSM antenna connector I p101 R101 R102 2102 c10 102 AEE pesos 1 Figure 39 GSM antenna matching circuit In this figure the components R101 R102 C101 and C102 is used for antenna matching the components value only can be got after the antenna
13. EXT 10K 100nF MOLEX 91228 SIM VDD 7 SIM RST DOR GND MODULE a et CIK VO PRESENCEGND 4 228 7 SIM CARD SIM DATA 588030 Figure 29 Reference circuit of the 8 SIM card holder The SIM_PRESENCE pin is used for detection of the SIM card hot plug in User can select the 8 pin SIM card 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 user can keep the SIM PRESENCE pin open The reference circuit of 6 pin SIM card holder 15 illustrated in the following figure SIM l00nF CARD SIM VDD SIM RST 228 vcc GND SIM_CLK 228 RST MODULE VO SIM DATA 23 C707 10M006 5122 Q gt i SMF05C Figure 30 Reference circuit of 6 SIM card holder 4 8 2 Design Considerations for SIM Card Holder For 6 pin SIM card holder SIMCom recommends to use Amphenol C707 10 006 5122 User can visit http www amphenol com for more information about the holder 34 2011 09 09 SIM908 C_Hardware Design_V1 01 Smart Machine Smart Decision 30 1 26 50 MOLES FOR P
14. down SIM908 C by PWRKEY 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 down procedure the module will send URC NORMAL POWER DOWN At this moment AT commands can not be executed any more and only the RTC is still active Power down mode can also be indicated by STATUS pin which is at low level at this time 4 2 2 2 Power down SIM908 C by AT Command SIM908 C can be powered down 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 down procedure the module will send URC NORMAL POWER DOWN At this moment AT commands can not be executed any more and only the RTC is still active Power down mode can also be indicated by STATUS pin which is at low level at this time For detail about the AT command please refer to document 1 SIM908 C Hardware Design V1 01 21 2011 09 09 Smart Machine Smart Decision 4 2 2 5 Over voltage or Under voltage Power down The module software monitors the VBAT voltage constantly If the voltage lt 3 3V the following URC will be reported UNDER VOLTAGE WARNNING If the voltage gt 4 7V the following URC will be reported OVER VOLTAGE WARNNING If the voltage lt 3 2
15. is not suitable for fast charging when its condition is DDLO or UVLO The SIM908 C provides a small constant current to the battery when the battery is between DDLO and UVLO In DDLO charging state SIM908 C gives out ImA current to the battery And in UVLO charging state SIM908 C provides about less than 200mA current to the battery DDLO charging terminates when the battery voltage reaches 1 5V UVLO charging terminates when the battery voltage is up to 3 3V Both DDLO and UVLO charge are controlled by SIM908 C hardware only Fast charge If there is a charger supply and battery present and the battery is not in DDLO and UVLO SIM908 C will enter fast charge state Fast charge is controlled by the software to make the current voltage regulation The charging scheme for the Li Ion battery is constant current about 550mA first followed by constant voltage charging once 4 2 is reached Charging is stopped when the charging current at constant voltage has decreased down to the pre set current 4 44 Operating modes during charging The battery can be charged during various operating mode That means that charging can be in progress while SIM908 C 15 in Normal mode SLEEP IDLE TALK GPRS IDEE or GPRS DATA mode In this case the voltage supply should be sufficient Here Charging in Normal mode is named as Charge mode If the charger is connected to the module s VCHG Pin and the battery is connected to the VBAT Pin while SIM908 C 15 in
16. level If user connects the module to the computer the level shifter should be added between the DCE and DTE For details about software upgrading please refer to document 4 SIM908 C Hardware Design V1 01 30 2011 09 09 Smart Machine Smart Decision 47 Audio Interfaces SIM908 C provides two analog inputs MICIP IN and MIC2P 2N which could be used for electret microphone The module also provides two analog outputs SPK1P 1N and SPK2P 2N The output can directly drive 320 receiver 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 and document 5 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 If user needs to use an amplifier circuit for audio National Semiconductor Company s LM4890 is recommended 4 7 Speaker Interface Configuration close as possible be placed to speaker as The lines in bold type should be accorded to differential signal layout rules MODULE These components s
17. pin GPS VANT should be kept open 5 4 GPS Antenna Interface 541 GPS Antenna Interface The GPS antenna interface has an impedance 0500 To suit the physical design of individual applications SIM908 offers a GPS antenna connector for customers as the figure 38 shows To minimize loss on the RF cable it need be very careful to choose cable SIMCom recommend the insertion loss should be meet following requirements GPS lt 0 905 The customer s antenna also can be located in the customer s main board and connect to module s antenna connector through RF cable and RF trace which impendence must be controlled in 500 To facilitate the antenna tuning and certification test a RF connector and an antenna matching circuit should be added The following figure is the recommended circuit MODULE GND Matching circuit Antenna feed pad GPS_ANT J101 GND 9 Figure 40 GPS antenna matching circuit In this figure the components R101 C101 and C102 is used for antenna matching the components value only can be got after the antenna tuning Usually matching components value is provided by antenna vendor the default value of R101 is 0Q and users need to reserve the place of C101 and C102 without soldering The traces in bold type should be treated as 50Q impedance controlled line in PCB layout SIM908 C_Hardware Design_V1 01 42 2011 09 09 Smart Machine Smart Decision
18. receiver to capture the desired satellite at the ideal orientation due to these noted gain nulls Once again careful testing in an appropriate anechoic chamber is required If the customer s design is for automotive applications then an active antenna can be used and located on top of the car in order for guarantee the best signal quality GPS 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 GPS reception performance depending on the customer s design SIM908 C Hardware Design V1 01 43 2011 09 09 Smart Machine Smart Decision 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 SIM908 C Table 19 Absolute maximum ratings VBAT Power supply voltage Va Input voltage 0 3 3l V 1 Input current 10 mA lo Output current 2 10 mA These parameters are for digital interface pins such as keypad GPIO PC UART LCD PWMs and DEBUG 6 2 Recommended Operating Conditions Table 20 Recommended operating conditions VBAT Power supply voltage 32 4 0 4 8 Operating temp
19. tuning Usually matching components value is provided by antenna vendor the default value of R TO and R102 00 and reserve the place of C101 and C102 without soldering The RF test connector J102 in figure 39 is used for conducted RF performance test and should be placed as close as possible to the module s GSM antenna connector The traces in bold type should be treated as 500 impedance controlled line in PCB layout For details about radio frequency trace layout please refer to document 9 SIM908 C Hardware Design V1 01 40 2011 09 09 Smart Machine Smart Decision 5 GPS Application Interface SIM908 C provides a high performance 1 1 GPS solution for cellular handset applications The solution offers best in class acquisition and tracking sensitivity Time To First Fix TTFF and accuracy The GPS engine supports both fully autonomous operations for use in handheld consumer navigation devices and other standalone navigation systems The GPS NMEA information is output by GPS port The default baud rate is 115200bps The GPS engine is controlled by GSM engine so when it is necessary to run GPS the GSM engine must be powered on and not in SLEEP mode All the GPS function is controlled by AT command via serial port The GPS functions AT commands are listed in the following table Table 18 AT Commands for GPS function Command Description AT CGPSPWR GPS POWER CONTROL AT CGPSRST GPS MODE RESET HOT WARM COLD AT CGPSST
20. 1 48 2011 09 09 Teen Acompany of SIM Smart Machine Smart Decision Table 30 SIM908 C conducted RF receive sensitivity GSM850 109dBm 107dBm EGSM900 109dBm 107dBm DCS1800 109dBm 107dBm PCS1900 109dBm 107dBm 6 10 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 31 SIM908 C operating frequencies GSM850 869 894MHz 824 849 MHz EGSM900 925 960MHz 880 915MHz DCS1800 1805 1880MHz 1710 1785MHz PCS1900 1930 1990MHz 1850 1910MHz 7 Manufacturing 7 4 Top View of SIM908 C IMEI 861001000004024 0678 Figure 41 Top view of SIM908 C 7 2 Moisture Sensitivity Level MSL SIM908 C is qualified to MSL3 in accordance with IPC JEDEC J STD 033 SIM908 C_Hardware Design_V1 01 49 2011 09 09 4 es 8 24 company of SIM Appendix A Related Documents Table 32 Related documents SN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Document name SIM908 C_AT Command Manual AN SIM900 TCPIP SIM900 Multiplexer User Manual Application Note AN SIM900 Series Update Tool UGD AN SIM900 AUDIO AN SIM900 Audio LINE IN input SIM900 Embedded Application Note AN Serial Port A
21. 5 23 29 21 59 2 43 55 04 53 34 24 22 88 2 44 56 31 54 61 2520 25 82 24 13 2 45 57 58 55 88 29 21 2 46 62 66 ORDER INFORMATION 2232 324812551 63 9g 6223 CONTACT PLATING gt FLASH 1 Astron a Ix ASTRON TECHNOLOGY CORP PH1 27mm 2 XXPin SWT FEMALE MAER OF ASTEOW 491 060 09T Figure 5 ASTRON Board to Board connector physical photo Note The connector ASTRON ASTRON1491060 09T R is used pin side SIM908 C module and 1590060 09T R is used in socket side user side SIM908 C_Hardware Design_V1 01 16 2011 09 09 HE of SIM Te me Smart Machine Smart Decision Qeeee 3 5 Mechanical dimensions of the RF connector The RF connector in the module side is an ultra small surface mount coaxial connectors Part Number U FL R SMT vended by HRS It has high performance with wide frequency range surface mountable and reflows solderable Following figure are the related parameters Certainly user visit http www hirose connectors com for more information To get good RF performance in user s design SIMCom suggests user to use the matching RF adapter cable which is also supplied by HRS Part Number U FL LP CV 040 the following figure is the dimensions of U FL series RF adapter cable User can contact SIMCom for more information 4 2247 oc 28 ES odo et TU S20
22. ATUS GET CURRENT GPS STATUS AT CGPSOUT GPS NMEA DATA OUTPUT CONTROL AT CGPSINF GET CURRENT GPS LOCATION INFO AT CGPSIPR SET GPS NMEA OUTPUT UART BPS For details of these AT command please refer to document 1 51 GPS operating modes GPS has two operating modes which can be controlled by AT command Active mode GPS i active as a GPS receiver The GPS engine will automatically acquire and track GPS satellites Power down mode The GPS engine will be set into this mode by sending AT command AT CGPSPWR 0 In this mode internal power supply for GPS will be shutdown and the current consumption is very low The last position current time and ephemeris data will be stored in the GSM host memory 5 2 Power on down Scenarios 5 2 1 Power on GPS engine User can power on GPS engine by sending AT command AT CGPSPWR 1 SIM908 C Hardware Design V1 01 4l 2011 09 09 Smart Machine Smart Decision 5 2 2 Power down GPS engine User can power down GPS engine by sending AT command AT CGPSPWR 0 53 GPS_VCC_RF and GPS_VANT GPS VCC RF is a 2 8V output for active external antenna if the active external antenna works at 2 8V voltage supply domain user can connect the GPS VCC RF and GPS VANT directly If the antenna s power is not 2 8V a proper voltage should be provided to the pin GPS VANT depending on the active antenna and the pin GPS VCC RF should be kept open For passive antennas both the pin GPS VCC and the
23. C Restricted operation 40 C 30 C and 80 C 85 Storage temperature 45 C 90 C GPRS data downlink transfer max 85 6 kbps GPRS data uplink transfer max 42 8 kbps Coding scheme CS 1 CS 2 CS 3 and CS 4 Integrate the TCP IP protocol Support Packet Broadcast Control Channel PBCCH Support CSD transmission Unstructured Supplementary Services Data USSD support MT MO CB Text and PDU mode SMS storage SIM card Group 3 Class 1 Support SIM card 1 8V 3V GSM RF connector 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 Full modem interface with status and control lines unbalanced asynchronous 1200bps to 115200bps 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 57600bps Debug port Null modem interface GPS DBG TXD GPS DBG RXD Can be used for debugging and upgrading firmware Support phonebook types SM FD LD RC ON MC GSM 11 14 Release 99 Support RTC Size 50mm x 33mm x 8 8mm Weight 11 1g Firmware upgradeable by debug port SIM908 C does work at this temperature but some radio frequency characteristics may deviate from the GSM specification SI
24. CTERISTICS amp y NJ iere 45 TABLE 24 SIM VDD CHARACTERISTICS tette ttt 45 TABLE 25 VRTC CHARACTERISTICS eerte tette ttt ttt 45 TABLE 26 GSM CURRENT CONSUMPTION ettet 46 TABLE 27 THE ESD CHARACTERISTICS TEMPERATURE 25 C HUMIDITY 45 96 47 TABLE 28 SIM908 C GSM 900 AND GSM 850 CONDUCTED RF OUTPUT POWER ees 47 TABLE 29 SIM908 C DCS 1800 AND PCS 1900 CONDUCTED RF OUTPUT etes 48 TABLE 30 SIM908 C CONDUCTED RF RECEIVE SENSITIVITY Ne 49 TABLE 31 SIM908 C OPERATING FREQUENCIES 49 TABLE 32 RELATED 50 TABLE 33 TERMSSANBD BBREVIATIONS 51 TABLE IEZ EINI DAON 8 7 ONA 52 SIM908 C_Hardware Design_V1 01 5 2011 09 09 Smart Machine Smart Decision Figure Index FIGURE 1 SIM908 C FUNCTIONAL 12 FIGURE 2 SIM908 C PIN OUT DIAGRAM BOTTOM 1 12 FIGURE 3 DIMENSIONS OF SIM908 C UNIT 15 FIGURE 4 ASTRON1590060 09T R BOARD TO BOARD 16 FIGURE 5 ASTRON BOARD TO BOARD CONNECTOR PHYSICAL PHOTO eee ee 16 FIGURE 6 U FL R SMT 17 FIGURE 7 U FL SERIES RF ADAPTER CABLE UNIT MUMD Ne 17 FIGURE 8 R
25. E 2 GPS ENGINE PERFORMANCE Ne 10 TABLE 3 CODING SCHEMES AND MAXIMUM NET DATA RATES OVER AIR INTERFACE e 10 TABLE 4 OVERVIEW OPERATING MODBES ettet ttt ttt 11 TABLE 5 PIN DESCRIPTION 13 TABLE 6 THE CURRENT CONSUMPTION OF MINIMUM FUNCTIONALITY MODE 23 TABLE 7 SPECIFICATION OF RECOMMENDED BATTERY PACK ettet 25 TABLE 8 CHARGE OPERATING 26 TABLE 9 AT COMMAND USUALLY USED IN CHARGE ONLY MODE Ne 27 TABLE 10 MICROPHONE INPUT CHARACTERISTICS ete tenes 33 TABLE 11 AUDIO OUTPUT CHARACTERISTICS tennis 33 TABLE 12 PIN DESCRIPTION AMPHENOL SIM CARD HOLDER ee re tenes 35 TABLE 13 PIN DESCRIPTION MOLEX SIM CARD HOLDER eee te ttes 36 TABLE 14 ADC SPECIFICATION Ne 37 TABLE 15 RI BEHAVIORS 37 TABLE 16 STATUS OF THE NETLIGHT 38 TABLE 17 PIN DEFINITION OF THE GPIO INTERFACE efe e e rct ttt 39 TABLE 18 AT COMMANDS FOR GPS FUNCTION ete e ettet ttt 41 TABLE 19 ABSOLUTE MAXIMUM RATINGS ee entente tentent tette 44 TABLE 20 RECOMMENDED OPERATING CONDITIONS aeterne 44 TABLE 21 DIGITAL INTERFACE CHARACTERISTICS 5 sette aaa 44 TABLE 22 SIM CARD INTERFACE CHARACTERISTICS 45 TABLE 23 VDD EXT CHARA
26. EFERENCE CIRCUIT OF THE LDO POWER 18 FIGURE 9 REFERENCE CIRCUIT OF THE DC DC POWER SUPPLY eene enne een 18 FIGURE 10 VBAT VOLTAGE DROP DURING TRANSMIT eee e Denn 19 FIGURE 11 THE MINIMAL VBAT VOLTAGE REQUIREMENT AT VBAT eene 19 FIGURE 12 POWERED ON DOWN MODULE USING 19 FIGURE 13 POWERED ON DOWN MODULE USING eene nennen 20 FIGURE 14 TIMING OF POWER 20 FIGURE 15 TIMING OF POWER DOWN SIM908 C 21 FIGURE 16 TIMING OF RESTART SIM908 C 22 FIGURE 17 SIM908 C WITH BATTERY CHARGER AND PACK 24 FIGURE 18 RTC SUPPLY FROM 28 FIGURE 19 RTC SUPPLY FROM NON CHARGEABLE BATTERY 28 FIGURE 20 RTC SUPPLY FROM RECHARGEABLE BATTERY 28 FIGURE 21 SEIKO 414 1 CHARGE DISCHARGE CHARACTERISTIC eee 29 FIGURE 22 CONNECTION OF THE SERIAL INTERFACES 5 29 FIGURE 23 CONNECTION OF RXD AND TXD ONN Re 29 FIGURE 24 CONNECTION FOR SOFTWARE UPGRADING AND eee eee 30 FIGURE 25 SPEAKER REFERENCE CIRCUIT 31 FIGURE 26 SPEAKER WITH AMPLIFIER REFERENCE CIRCUIT 31 FIGURE 27 MICROPHONE REFERENCE
27. M908 C Hardware Design V1 01 9 2011 09 09 Smart Machine Smart Decision Table 2 GPS engine Performance 4 Table 3 Coding schemes VM net data rates over air interface SIM908 C Hardware Design_V1 01 10 2011 09 09 Smart Machine Smart Decision 2 2 Operating Modes The table below summarizes the various operating modes of SIM908 C Table 4 Overview of operating modes Mode Normal operation Power down Minimum functionality mode Charge only mode Charge mode during normal operation SIM908 C_Hardware Design_V1 01 11 Function Module will automatically go into sleep mode if the conditions of sleep mode are enabling and there is no on air and no hardware interrupt such as GSM GPRS GPIO interrupt or data on serial port SLEEP 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 Software is active Module registered to the GSM network and the module IDLE is ready to communicate GSM Connection between two subscribers is in progress In this case the power TAE consumption depends on network settings such as DTX off on FR EFR HR hopping sequences antenna GPRS Module is ready for GPRS data transfer but no data is currently sent or received In this case power consumption depends on network settings a
28. N SIM900 TE PCB Layout amp Schematic for Reference Module secondary SMT UGD ITU T Draft recommendation V 25ter GSM 07 07 new GSM 07 10 GSM 07 05 GSM 11 14 GSM 11 11 GSM 03 38 GSM 11 10 SIM908 C Hardware Design V1 01 Smart Machine Smart Decision Remark SIM908 C AT Command Manual TCP IP Applications User Manual SIM908 C Multiplexer User Manual Application Note SIM908 C Series Update Tool User Guide Applications Note About SIM908 C Audio Applications Note About SIM908 C LINE IN Input SIM908 C Embedded AT Application Note Application Note About Serial Port Application Note About SIM908 C TE PCB Layout amp Schematic Module secondary SMT User Guide Serial asynchronous automatic dialing and control Digital cellular telecommunications Phase 2 AT command set for GSM Mobile Equipment ME Support GSM 07 10 multiplexing protocol 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 Digital cellular telecommunications system Phase 2 Specification of the SIM Application Toolkit for the Subscriber Identity Module Mobile Equipment SIM ME interface Digital cellular telecommunications system Phase 2 Specification of the Subscriber Identity Module Mobile Equipment SIM ME interface Digital cellular telecommunicatio
29. PE s Figure 32 Molex 91228 SIM card holder Table 13 Pin description Molex SIM card holder Pinmme Signal 0 SIM VDD SIM card power supply C2 SIM RST SIM card reset C3 SIM CLK SIM card clock C4 GND Connect to GND 5 GND Connect to GND C6 VPP Not connect C7 SIM DATA SIM card data I O C8 SIM PRESENCE Detect SIM card presence 4 9 LCD Display SPI Interface SIM908 C provides a serial LCD display interface It could also be used as SPI interface in the embedded AT application For details about embedded AT application please refer to document 7 Note This function is not supported in the standard firmware If user wants this function the firmware must be customized Please contact SIMCom for more details SIM908 C Hardware Design V1 01 36 2011 09 09 Smart Machine Smart Decision SIM908 C provides an auxiliary ADC which can be used to measure the voltage User can use AT command to read the voltage value For details of this AT command please refer to document 1 Table 14 ADC specification Voltage range 0 2 8 ADC Resolution 10 bits Sampling rate 200K Hz 4 11 RI Behaviors Table 15 RI Behaviors Standby High 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 Voice call The pin is changed to low When any of the following events occur the
30. POWER DOWN mode SIM908 C will go into the Charge only mode The following table gives the difference between Charge mode and Charge only mode Table 8 Charge operating modes How to activate mode Features Connect charger to module s VCHG Pin GSM remains operational and registers and connect battery to VBAT Pin of to GSM network while charging is in module while SIM908 C is in Normal progress operating mode including The serial interfaces are available in IDLE TALK mode SLEEP mode etc IDLE TALK mode the AT command set can be used fully in this case Charge Mode In SLEEP mode the serial interfaces are not available Once the serial port is connected and there is data in transfer SIM908 C will exit the SLEEP mode SIM908 C Hardware Design V1 01 26 2011 09 09 Smart Machine Smart Decision Connect charger to module s VCHG Pin 9 Battery can be charged when GSM while SIM908 C is in POWER DOWN engine is not registered to GSM gt mode network Only a few commands is available IMPORTANT Here Charge only mode is as listed below charging when power is down it means that not all software tasks are running Note VBAT can not provide more than 5mA current while SIM908 C module is during the DDLO charge state In other words it is strongly recommended that VBAT should not be the main power supply in the application subsystem if SIM908 C DDLO charging state occurs Table 9 AT Comman
31. Power Supply Z rrr RE 19 4 2 Power on down Scenarios RN 19 421 51 908 a E Jm 19 4 2 2 Power down 1 908 2222 22 42442442 12 1 21 4 23 Restart SIM908 C by PWRKEPig 22 43 Power Saving meis nnne 23 4 3 1 Minimum Functionality 23 432 Sleep Mode 1 9559 559 55995094589443944 tenete tone 23 433 Wake Up SIM908 C from Sleep Mode 1 AT CSCLK 1 5 9559959959999999959959 9 23 434 Sleep Mode 2 AT CSCLK 2 24 435 Wake Up SIM908 C from Sleep Mode 2 AT CSCLK 2 24 4 4 CPI Sh adc P 24 4 4 Battery pack 8 8 1 6 15 658 u SS 25 4 4 2 Recommended battery pack 25 443 Implemented charging technique nennen nhe enne 25 4 4 4 Operating modes during charging
32. RODUCTION LINE 59 1 v DIMERS Om ONLY DRINS LOCKING Figure 31 Amphenol C707 10 006 5122 SIM card holder Table 12 Pin description Amphenol SIM card holder SIM VDD SIM card power supply C2 SIM RST SIM card reset C3 SIM CLK SIM card clock 85 GND Connect to GND C6 VPP Not connect C7 SIM DATA SIM card data I O For 8 pins SIM card holder SIMCom recommends to use Molex 91228 User can visit http www molex com for more information about the holder SIM908 C Hardware Design V1 01 35 2011 09 09 hs m eo E was Smart Machine Smart Decision RECEDED LAYOUT 2 1 NOTES 1 SEE PRODUCT SPECIFICATION 5 99020 0071 2 PACKING TAPE AND REEL FOR DETAIL SEE 50 91228 9001 SHT 1 3 PUSH ROD LEVER MUST NOT PROTRUDE BEYOND HOUSING EDGE IN THIS AREA 4 TAILS ON EACH SIDE OF CONNECTOR TO LIE WITHIN O l2mm OF EACH OTHER COMPONENT MATERIAL HOUSING LIQUID CRYSTAL POLYMER LCP 30 GLASS FILL ULS4 0 COLOUR BLACK V TERMINAL 0 15 PHOSPHOR BRONZE O lum MIN Au OVER CONTACT AREA 2 5um MIN Sn ON SMT TAILS V PUSH BUTTON 1 GF NYLON 46 YELLOW COIL SPRING 0 25 STAINLESS STEEL W PUSH 800 0 4 STAINLESS STEEL 2 REVISE ONLY ON CAD SYSTEM Tce SIM CONNECTOR MOLEX EURO
33. SIM Card Interface Characteristics Aeres UW e ssuassssssasqesssasssesasssaqasssasatasskassswkaqasssqassasakasskassswsaqas 45 6 5 NDD BENT Characteristics NA 45 6 6 SIM VDD CharacteristicSs AN 45 6 7 WV RAC Characteristics cues tues 45 6 8 Current Consumption VBAT 3 8 GPS engine is powered dowWn 46 6 9 Electro Static Discharge 47 6 10 Radio gy civiecccsscsecicesisesccsssdecseessdececonededsuassaeteeasazecseasedeteoanedacsoassaacennsedscsonseauieanseaadantegedenves 47 6 10 1 d 47 6 10 2 RIwReCeive Sensitivity 48 6 10 3 Modul Operating FrequencieS 49 7 uu cM 49 7 1 View of SIM908 G 49 7 2 Moisture Sensitivity Level 49 EY C 50 A Related Documents ERE H 50 Terms and Abbreviations 51 C Daey 52 SIM908 C_Hardware Design_V1 01 4 2011 09 09 Smart Machine Smart Decision Table Index TABLE 1 SIM908 C GSM GPRS ENGINE KEY FEATURES Ne 8 TABL
34. V the following URC will be reported and the module will be automatically powered down UNDER VOLTAGE POWER DOWN If the voltage gt 4 8V the following URC will be reported and the module will be automatically powered down OVER VOLTAGE POWER DOWN At this moment AT commands can not be executed any more and only the RTC is still active Power down mode can also be indicated by STATUS pin which is at low level at this time 4 2 2 4 Over temperature or Under temperature Power down The module will constantly monitor the temperature of the module If the temperature gt 80 C the following URC will be reported CMTE 1 If the temperature lt 30 C the following URC will be reported CMTE 1 If the temperature gt 85 C the following URC will be reported and the module will be automatically powered down CMTE 2 If the temperature lt 40 C the following URC will be reported and the module will be automatically powered down 2 At this moment AT commands can be executed any more and only RTC is still active Power down mode can also be indicated by STATUS which is at low level at this time AT command could be used to read the temperature when the module is running For details please refer to document 1 4 2 3 Restart SIM908 C by PWRKEY Pin When the module works normally if the user wants to restart the module follow the procedure below 1 Powerdown the mo
35. d usually used in Charge only mode AT command Function AT CCLK Set data and time of RTC AT CPOWD Power down AT CBC Indicated charge state and voltage AT CFUN Start or close the protocol Set AT command AT CFUN 1 module can be transferred from Charge only mode to Charging in normal mode In Charge only mode the default value is 0 4 4 5 Charger requirements Following is the requirements of charger for SIM908 C Simple transformer power plug Output voltage 5 0V 6V Minimum supply current 750mA 10 peak voltage is allowed for maximum 1115 when charging current is switched off 1 6A peak currents allowed for maximum 1115 when charging current is switched on 4 5 RTC Backup Current input for RTC when the VBAT is not supplied for the system Current output for backup battery when the VBAT power supply is in present and the backup battery is in low voltage state The RTC power supply of module 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 SIM908 C_Hardware Design_V1 01 27 2011 09 09 Smart Machine Smart Decision External capacitor backup MODULE VRTC 10K RTC SU ab ow i Large capacitance B Figure 18 RTC supply from capacitor Non chargeable battery backup MODULE VRTC 10K RTC Y gt
36. dule 2 Wait for at least 800mS after STATUS pin changed to low level 3 Power on the module Power down Delay gt 800mS Restart i gt a gt gt PWRKEY STATUS Figure 16 Timing of restart SIM908 C SIM908 C_Hardware Design_V1 01 22 2011 09 09 Smart Machine Smart Decision 4 3 Power Saving Mode SIM908 C has two sleep modes sleep mode 1 15 enabled by hardware pin DTR sleep mode 2 is only enabled by serial port regardless of the DTR In sleep mode the current of module is very low The AT command AT CFUN lt fun gt can be used to set SIM908 C into minimum functionality When SIM908 C is in sleep mode and minimum functionality the current of module is lowest 4 3 4 Minimum Functionality Mode There are three functionality modes which could be set by the AT command AT CFUN lt fun gt The command provides the choice of the functionality levels lt fun gt 0 1 4 0 minimum functionality 1 full functionality default 4 flight mode disable RF function Minimum functionality mode minimizes the current consumption to the lowest level If SIM908 C 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 all AT commands correlative with RF function and SIM card function will not be accessible For detailed information about AT Command AT CFUN lt fun gt
37. e Input Characteristics Parameter Min Typ Max Unit Working Voltage 1 2 1 5 2 0 Working Current 200 500 uA External Microphone Load Resistance 1 2 22 Internal biasing DC Characteristics DES V Differential input THD lt 1 at 15 9 mVrms voltage F 1KHz pre amp gain 20 dB PGA gain 14 dB THD lt 5 740 mVrms F 1KHz pre amp gain 0 dB PGA gain 0 dB Table 11 Audio Output Characteristics Parameter Conditions Min Typ Max Unit RL 320 91 mW THD 0 1 RL 320 96 mW THD 1 Normal Output swing Output SPK Voltage 1 1 single ended Output swing Voltage 22 differential 4 8 SIM Card Interface 4 81 SIM Card Application The SIM interface complies with the GSM Phase 1 specification and the new GSM Phase 2 specification for FAST 64 kbps SIM card Both 1 8V and 3 0V SIM card are supported The SIM interface is powered from an internal regulator in the module It is recommended to use an ESD protection component such as ST www st com ESDA6V1W5 or ON SEMI www onsemi com SMFOSC The pull up resistor 15 on the SIM DATA line is already added in the module internal Note that the SIM peripheral circuit should be close to the SIM card socket The reference circuit of the 8 pin SIM card holder is illustrated in the following figure SIM908 C_Hardware Design_V1 01 33 2011 09 09 Smart Machine Smart Decision VDD
38. e 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 featu
39. e network 64ms On 300ms Off PPP GPRS communication is established A reference circuit is recommended in the following figure SIM908 C Hardware Design V1 01 38 2011 09 09 Smart Machine Smart Decision MODULE VBAT NETLIGHT 47 Figure 37 Reference circuit of 4 13 General Purpose Input Output GPIO SIM908 C provides 2 GPIO pins The output voltage level of the GPIO can be set by the AT command AT SGPIO The input voltage level of the GPIO can also be read by the AT command AT SGPIO For more details please refer to document 1 Table 17 Pin definition of the GPIO interface Pin name Pin number Default function Default state GPIOO 34 GPIOO Output pull down GPIO1 22 GPIO Output pull down 4 14 BUZZER Features of buzzer 10 bit resolution for buzzer tone frequency generation from 200 Hz to 5 kHz Tone frequency error lt for all standard piano notes from 200 Hz to 5 kHz Tone level control from 0 dB down to 24 dB in 4 dB steps Audio mute The buzzer outputs a square wave at the desired tone frequency The tone frequencies are programmable from 200 Hz to 5 kHz and can be re programmed on the fly to generate monophonic audio ring tones or alert tones The tone level can be adjusted over a 24 dB range in 4 dB steps or it can be muted 4 15 GSM Antenna Interface The GSM antenna interface has an impedance
40. erature 40 2525 85 je Storage temperature 45 90 6 3 Digital Interface Characteristics Table 21 Digital interface characteristics High level input current uA Ig Low level input current 10 10 uA Vin High level input voltage 2 4 Vit Low level input voltage 0 4 High level output voltage 2 7 Vor Low level output voltage 0 1 V e These parameters are for digital interface pins such as keypad GPIO PC UART LCD PWMs and DEBUG SIM908 C Hardware Design V1 01 44 2011 09 09 Smart Machine Smart Decision 6 4 SIM Card Interface Characteristics Table 22 SIM card interface characteristics 65 VDD_EXT Characteristics K v E m gt lt 5 6 2 6 6 SIM VDD Characteristics Table 24 SIM_VDD Symbol Parameter Unt 9 25 2 30 15 160 15 67 Characteristics Table 25 VRTC characteristics SIM908 C Hardware Design V1 01 45 2011 09 09 iu LII 2 20 company of SIM Tech 6 8 Current Consumption VBAT 3 8V GPS engine is powered down Smart Machine Smart Decision Table 26 GSM Current consumption SIM908 C Hardware Design V1 01 Smart Machine Smart Decision 6 9 Electro Static Discharge SIM908 C is an ESD sensit
41. gnal SIM908 C sends out result code as following when fixed baud rate set RDY CHARGE ONLY MODE When user drives the PWRKEY of Charge only mode SIM908 C to a low level voltage for a period of time please refer to Figure 13 Timing of power on module the SIM908 C will power up and go into Charge mode during normal operation In this case SIM908 C sends out result code as following From CHARGE ONLY MODE to NORMAL MODE SIM908 C Hardware Design V1 01 20 2011 09 09 Smart Machine Smart Decision In Charge mode during normal operation all operations and AT commands are available 4 2 2 Power down SIM908 C SIM908 C will be powered down in the following situations Normal power down procedure power down SIM908 C by the PWRKEY pin Normal power down procedure power down SIM908 C by AT command AT CPOWD 1 Abnormal power down over voltage or under voltage automatic power down Abnormal power down over temperature or under temperature automatic power down 4 2 2 1 Power down SIM908 C by PWRKEY Pin User can power down SIM908 C by pulling down the PWRKEY pin for at least 1 second and release Please refer to the power on circuit The power down scenario is illustrated in following figure 5 gt Tpulldown gt 1S gt 1 75 PWRKEY gt Input Logoff net gt 2 4 STATUS Output Vou Serial Port Active X Undefined Figure 15 Timing of power
42. hould be placed to I 1 speaker as close as possible in type should be accorded to differential signal layout rules boy 755 10pF 33pF ESD Amplifier i ANTI SPK2P ra Circuit MODULE 33pF SPK2N gt TUB ES 10pF 33pF Y ANTI Figure 26 Speaker with amplifier reference circuit SIM908 C Hardware Design V1 01 31 2011 09 09 Smart Machine Smart Decision 4 7 3 Microphone Interfaces Configuration These components should be placed to microphone as close as possible The lines in bold type should be accorded to differential signal layout rules Electret TOBE 33pF MODULE Microphone 10pF Figure 27 Microphone reference circuit Microphone input also could be used to LINE IN input For details please refer to document 6 4 7 3 Earphone Interface Configuration The lines in bold type should be accorded to differential signal layout rules MODULE 5 2 10R 3 35 7 33pF 10pF S 4 N S3pF 33pF ANTI L2 f Amphenol 9001 8905 050 Figure 28 Earphone reference circuit SIM908 C Hardware Design V1 01 32 2011 09 09 Smart Machine Smart Decision 4 7 4 Audio Electronic Characteristics Table 10 Microphon
43. igure for the reference circuit SIM908 C Hardware Design V1 01 24 2011 09 09 Smart Machine Smart Decision 4 4 1 Battery pack characteristics SIM908 C has optimized the charging algorithm for the Li Ion battery that meets the characteristics listed below The maximum charging voltage of the Li Ion battery pack is 4 2V and the recommended capacity 15 1100mAh The Battery packs with more than 1100 mAh capacity will take more time for charging The battery pack should have a protection circuit to avoid overcharging deep discharging and over current and the circuit should be insensitive to pulsed current The internal resistance of the battery pack including protection circuit should be as low as possible Its recommended value does not exceed 150mQ The battery pack must be protected from reverse pole connection On the SIM908 C the build in circuit of the power management chipset monitors the supply voltage constantly Once the Under voltage is detected the SIM908 C will be powered down automatically 4 4 Recommended battery pack Following is the specification of recommended battery pack Table 7 Specification of recommended battery pack Items Description Battery type Li ion Manufacturer Jiade Energy Technology Normal voltage 3 7V Capacity NORMAL 1100mAh Charge Voltage 4 200 0 050 Max Charge Current 1 0C Charge Method CC Constant Current Constant Voltage Max Discharge Current 1 0 f
44. ing transmit burst 411 Minimizing Voltage Drop of VBAT When designing the power supply in user s application pay special attention to power losses Ensure that the input voltage never drops below 3 1 V even when current consumption rises to 2A in the ransmit burst If the power voltage drops below 3 1V 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 and the bypass capacitor should be placed to the module as close as possible VBAT Min 3 1V Figure 11 The minimal VBAT voltage requirement at VBAT drop 41 2 Monitoring Power Supply The AT command can be used to monitor the VBAT voltage For detail please refer to document 1 4 2 Power on down Scenarios 4 2 1 Power on SIM908 C 4 2 1 1 Turn SIM908 C Using the PWRKEY Pin Power on User can power on SIM908 C 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 circuit is shown as below 100K PWRKEY Power on down logic 4 7K Turn on off impulse MODULE Figure 12 Powered on down module using transistor SIM908 C_Hardware Design_V1 01 19 2011 09 09
45. interrupts such as GPIO interrupt SIM908 C will enter sleep mode 2 automatically In this mode SIM908 C can still receive paging or SMS from network but the serial port is not accessible Note For SIM908 C It is requested to set AT command AT CSCLK 2 to enable the sleep mode 2 the default value is 0 which can not make the module to enter sleep mode For more details please refer to document 1 4 3 5 Wake Up SIM908 C from Sleep Mode 2 AT CSCLK 2 When SIM908 C is in sleep mode 2 AT CSCLK 2 the following methods can wake up the module Send data to SIM908 C via main serial Receive a voice or data call from network Receive a SMS from network Note The first byte of the user s data will not be recognized 4 4 Charging interface SIM908 C has integrated a charging circuit inside the module for Li Ion batteries charging control which make it very convenient for user s applications that support battery charging A common connection is shown in the following figure 5V Module Battery Pack TEMP Rremp Thermistor Figure 17 SIM908 C with battery charger and pack connection Battery temperature measurement is a customization function which is supported by the software in the module In above figure the is a NTC thermistor and it is recommended to use MURATA NCP15XH103FO03RC Its impedance is l0Kohm at 25 C Refer to the above f
46. ireless Solutions Ltd 2011 SIM908 C Hardware Design V1 01 2 2011 09 09 Smart Machine Smart Decision Contents Contents 3 Version HIStoFy sa e 7 1 Im PO elon 8 2 SIM908 C Overview 225 55 8 2 1 SIM908 C Key MIT CHEM 8 2 2 Operating Modes e RE ERR 11 2 3 SIM908 C Functional 20 2020220 12 3 Package Informati n III eme ese Nares annee ere 12 3 1 Dia TAI dis 12 3 2 13 3 3 Package Dimensions 15 3 4 Board to board connector 15 3 4 Mechanical dimensions of the ASTRON 1590060 091 8 55 410000000000 16 3 5 Mechanical dimensions of the RF connector a eene enne nnne 17 4 GSM Application Interface eere eric r erroe Ne sss Nueve nete neo Ya avo envers Pana aepo 18 4 1 Power cce eret e MN Er RM RE 18 411 Minimizing Voltage 19 4 1 2 Monitoring
47. is designed with power saving technique so that the current consumption is as low as 1 0mA in sleep mode GPS engine is powered down SIM908 C 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 21 SIM908 C Key Features Table 1 SIM908 C GSM GPRS engine key features Feature Implementation Power supply 32V 4 8V Typical power consumption in sleep mode is 1 0mA BS PA MFRMS 9 GPS Power saving dA engine is powered down Charging Supports charging control for Li Ion battery SIM908 C Quad band GSM 850 EGSM 900 DCS 1800 PCS 1900 Frequency bands SIM908 C can search the 4 frequency bands automatically The frequency bands also can be set by AT command For details please SIM908 C Hardware Design V1 01 8 2011 09 09 Transmitting power GPRS connectivity Temperature range Data GPRS CSD USSD SMS FAX SIM interface External antenna Audio features Serial port and debug port Phonebook management SIM application toolkit Real time clock Physical characteristics Firmware upgrade Smart Machine Smart Decision refer to document 1 Compliant to GSM Phase 2 2 Class 4 2W at GSM 850 and EGSM 900 Class 1 1W at DCS 1800 and PCS 1900 GPRS multi slot class 10 default GPRS multi slot class 8 option Normal operation 30 C 80
48. ive component so more attention should be paid to the procedure of handling and packaging The ESD test results are shown in the following table Table 27 The ESD characteristics Temperature 25 C Humidity 45 6 10 Radio Characteristics 6 10 1 Module RF Output Power The following table shows module conducted output po E owed by the 3GPP TS 05 05 technical specification requirement SD Table 28 SIM908 C GSM 900 and GSM 850 co ND output power Z SIM908 C_Hardware Design_V1 01 47 2011 09 09 Smart Machine Smart Decision Table 29 SIM908 C DCS 1800 and PCS 1900 conducted RF output power C For the module s output power the following is should be noted 33dBm and at t aximum power level the output power tolerance should not exceed 2dB under normal At GSM900 and the module is a class 4 device the module s output power should not exceed condition and under extreme condition At PCS1900 band module is a class 1 device 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 10 2 Module RF Receive Sensitivity The following table shows the module s conducted receive sensitivity it is tested under static condition SIM908 C Hardware Design_V1 0
49. nd STANDBY GPRS configuration There is GPRS data transfer PPP or TCP or UDP in progress In this case GPRS power consumption is related with network settings e g power control DATA level uplink downlink data rates and GPRS configuration e g used multi slot settings Normal power down by sending the AT command AT CPOWD 1 or using PWRKEY The power management unit shuts down the power supply for the baseband part of the module and only the power supply for the RTC is remained Software is not active The serial port is not accessible Power supply connected to VBAT remains applied 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 The module will enter Charge only mode automatically when a charger and battery are connected to a switched off SIM908 C In this mode the module does not search for network and has limited access to available AT commands available The module can also enter Charge only mode from Charge mode during normal operation by normally powered down the module The module will automatically go to this mode when a charger is connected to a Normal operation mode module when battery voltage is no
50. ns system Phase 2 Alphabets and language specific information Mobile Station Part 1 Conformance specification Digital cellular telecommunications system Phase 2 MS conformance specification 50 2011 09 09 2 421 5 gt gt 5 Table 33 Terms Abbreviations 2011 09 09 2 e gt 2 E lt M gt USSD Smart Machine Smart Decision Unsolicited Result Code Unstructured Supplementary Service Data Phonebook abbreviations FD LD MC ON RC SM NC SIM fix dialing phonebook SIM last dialing phonebook list of numbers most recently dialed Mobile Equipment list of unanswered MT calls missed calls SIM or ME own numbers MSISDNs list Mobile Equipment list of received calls SIM phonebook Not connect C Safety Caution Table 34 Safety caution Marks x 4 2 D 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 th
51. omatically detect the baud rate of the host device Pay more attention to the following requirements Synchronization between DTE and DCE When DCE powers with autobauding enabled user must firstly send character to synchronize the baud rate It is recommended to send AT until DTE receives the OK response which means DTE and DCE are correctly synchronized For more information please refer to the AT command 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 User 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 1 and READY will be reported when SIM908 C is powered on Debug port Used for debugging and upgrading firmware Debug port supports the baud rate of 115200bps 4 6 2 Software Upgrade and Debug Refer to the following figure for debugging and upgrading software MODULE RS232 PC DBG TXD MM TXD OUT O O RXD gt OUT 1 TXD VBAT C PWRKEY GND C Figure 24 Connection for software upgrading and debugging The serial port and the debug port support the CMOS
52. or continuous discharging mode Discharge Cut off Voltage 3 0V cell Internal resistance Initial lt 130mQ 4 4 3 Implemented charging technique 51 908 has battery charging function There are three pins related to the battery charging function there are VBAT and TEMP BAT ADCO pins The Pin is driven by an external voltage system can use this Pin to detect a charger supply and provide most charging current through SIM908 C module to battery when charging is in fast charge state VBAT pin gives charging current to external battery from SIM908 C module TEMP BAT Pin is for user to measure the battery temperature Let this Pin open if battery temperature measurement is not user s design concern It is very simple to implement charging function user just needs to connect the charger to the VCHG Pin and connect the battery to the VBAT Pin SIM908 C battery charging happens after detecting charger supply and the presence of battery If there is no charger supply or no battery present charging function will not be enabled SIM908 C Hardware Design V1 01 25 2011 09 09 Smart Machine Smart Decision Normally there are three main states in the whole charging procedure DDLO charge Pull up mode and UVLO charge Pre charge mode Fast charge DDLO charge and UVLO charge DDLO is the state of battery when its voltage is under 1 5V And UVLO means the battery voltage is less than 3 3V and more than 1 5V The battery
53. pin will be changed to high 1 Establish the call 2 Hang up the call Data call The pin is changed to low and kept low for 120ms when a SMS is received Then it is changed to high SMS TE The is changed to low and kept low for 120ms when some URCs are reported Then it is changed to high For more details please refer to document 8 The behavior of the RI pin is shown in the following figure when the module is used as a receiver RI HIGH Establish the call Hang up the call Idle Ring Figure 33 RI behaviour of voice calling as a receiver SIM908 C_Hardware Design_V1 01 37 2011 09 09 Smart Machine Smart Decision RI HIGH Establish the call Hang up the call Idle Ring Figure 34 RI behaviour of data calling as a receiver P 120 5 LOW Cue Idle Receive SMS URC Figure 35 RI behaviour of URC or receive SMS However if the module is used as caller the RI will remain high Please refer to the following figure HIGH RI Idle Ring Establish Hang up Idle the call the call Fig re 36 RI behaviour as a caller 4 12 Network Status Indication The NETLIGHT used to drive a network status indication LED The status of this pin is listed in following table Table 16 Status of the NETLIGHT pin Off SIM908 C is not running 64ms On 800ms Off SIM908 C not registered the network 64ms On 3000ms Off SIM908 C registered to th
54. res 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 SIM908 C_Hardware Design_V1 01 52 2011 09 09 or SIM Tech Acompany Smart Machine Smart Decision Contact us Shanghai SIMCom Wireless Solutions Ltd Add SIM Technology Building No 633 Jinzhong Road Changning District Shanghai China 200335 Tel 86 21 3252 3300 Fax 86 21 3252 3301 URL www sim com wm SIM908 C Hardware Design V1 01 53 2011 09 09
55. sed in user s application other serial pins should be kept open Please refer to following figure MODULE DCE CUSTOMER DTE Serial port Serial port1 TXD TXD RXD Lee RXD RTS 0 RTS CTS moO CTS DIR 0 DTR DCD DCD RI RING Debug port Serial port2 DBG_TX RXD Figure 22 Connection of the serial interfaces MODULE DCE CUSTOMER DTE Serial port Serial port1 TXD TXD RXD RXD RTS RTS CTS CTS DTR o x DTR DCD o x DCD RI RING Debug port Serial port2 GPS DBG_TX GPS DBG_RX RXD Figure 23 Connection of RXD and TXD only 4 6 1 Function of Serial Port and Debug Port Serial port Full modem device Contains data lines TXD and hardware flow control lines RTS and CTS status lines DCD and RI Serial port can be used for CSD FAX GPRS service and AT communication It can also be used for multiplexing function For details about multiplexing function please refer to document 3 SIM908 C_Hardware Design_V1 01 29 2011 09 09 Smart Machine Smart Decision Serial port supports the following baud rates 1200 2400 4800 9600 19200 38400 57600 and 115200bps Autobauding only supports the following baud rates 1200 2400 4800 9600 19200 38400 and 57600bps The default setting is autobauding Autobauding allows SIM908 C to aut
56. sired output VBA T 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 DC input U101 LM2596 ADJ L101 FB101 VBAT FUSE 4 AAA FF 9 Vin Vout LV Y Y 5 100uH 270 OHM ON TVS101 cor q102 24 2 102 c103 104 SMBJ15A 100uF 1 330uF T 1400 PWR_CTRL 3 7 MBR360 R102 Figure 9 Reference circuit of the DC DC power supply The single 3 7V Li ion cell battery can be connected to SIM908 C 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 pins should be less than 150mQ 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 100HhF tantalum capacitor ESR 0 7Q Another VBAT bypass capacitor 11 SIM908 C_Hardware Design_V1 01 2011 09 09 Smart Machine Smart Decision 577uS_ 4615 8 Pu Burst 2A lvBAT VBAT Max 300mV Figure 10 VBAT voltage drop dur
57. ss than 60x60mm then compromises to the beam width and gain pattern could result Usually the gain becomes very directional looses several dB of performance Since results can vary measuring the antenna radiation pattern in the final housing in an appropriate anechoic chamber is required Some customers do not have the size availability to implement a patch antenna approach In that instance use of a Linear Polarized LP antenna is the next best alternative There are new ceramic LP antennas on the market that exhibit reasonable gain characteristics once properly mounted in the housing and when matched to an appropriate sized ground Generally the ground plane requirements are smaller for a LP antenna when compared to a patch but once again proper testing in an anechoie chamber is a mandatory requirement These ceramic elements will need to be located near the end of the ground plane and will require several millimeters of clearance between the closest component It is important to note that use of a LP antenna will result in a minimum of 3dB of gain loss when compared to 8 RHCP antenna at a defined elevation This is due to the right hand gain rule of antenna propagation Use of PIFA antenna is another LP possibility but the PIFA usually exhibits a considerable amount of gain nulls or holes in the radiation pattern This will be undesirable for obtaining a low circular error probability CEP since the antenna may not allow the
58. stand SIM908 C interface specifications electrical and mechanical details With the help of this document and other SIM908 C application notes user guide users can use SIM908 C to design various applications quickly 2 SIM908 C Overview Designed for global market SIM908 C is integrated with a high performance GSM GPRS engine and a GPS engine The GSM GPRS engine is a quad band GSM GPRS module that works frequencies GSM 850MHz EGSM 900MHz DCS 1800MHz and PCS 1900MHz SIM908 C features GPRS multi slot class 10 class 8 optional and supports the GPRS coding schemes CS 1 CS 2 CS 3 and CS 4 The GPS solution offers best in class acquisition and tracing sensitivity Time To First Fix and accuracy With a tiny configuration of 50mm x 33mm 8 8mm SIM908 C can meet almost all the space requirements in user applications such as M2M smart phone PDA tracker and other mobile devices SIM908 C has 60 PIN DIP connector provides all hardware interfaces between the module and customers boards Serial port and debug port can help user easily develop user s applications GPS Serial port Two audio channels include two audio inputs and two audio outputs These can be easily configured by command Charging interface Programmable general purpose input and output The keypad and SPI display 1016118668 will give users the flexibility to develop customized applications RF connector interface SIM908 C
59. t lower than 3 2V Normal operation mode includes SLEEP IDLE TALK GPRS IDLE and GPRS DATA 2011 09 09 Smart Machine Smart Decision 2 3 SIM908 C Functional Diagram The following figure shows a functional diagram of SIM908 C The GSM baseband engine The GPS engine The GSM radio frequency part The antenna interface The other interfaces 4 RTC Radio Power Power management unit Frequency supply T V Digital Interface GPS lt Receiver SIM UART Analog base Digital base J 58105 lt Analog Interface L PWMs_ gt im gt Audio gt LCD SPI amp p ADC GPS 4 UART FLASH Figure 1 SIM908 C functional diagram 3 Package Information 31 Pin out Diagram 51 908 BOTTOM VIEW SP_D C SP_CLK SP_CS SP_DATA GPS_VCC_RF GPIOI TEMP BAT N 5 E 574105 Wis BUZZER z vc ON 5 E nc s E E WIS 5 2 gH I s NETLIGHT Kaw 5 on xc 8 8 E ev 8 SLO E cproo axi E nisp 5

SIM908-C_Hardware Design_V1.01

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