SIM900D_Hardware Design_V2.02 - MT
Contents
1. 38 FIGURE 36 REFERENCE CIRCUIT OF NETLIGHT 39 FIGURE 37 ANTENNA MATCHING CIRCUIT 40 FIGURE 38 TOP AND BOTTOM VIEW OF SIM900_ 47 FIGURE 39 TYPICAL SOLDER REFLOW PROFILE 47 SIM900D_Hardware Design_V2 02 6 2012 05 07 Version History Date Version 2010 03 31 1 01 2010 04 09 1 02 2010 06 24 1 03 2010 10 09 1 04 2011 04 01 2 00 2012 02 23 2 01 2012 05 07 2 02 SIM900_Hardware Design_V2 02 Smart Machine Smart Decision Description of change Origin Changed GHOST mode to Charge only mode 3 4 1 1Update the Figure Timing of turn on system using PWRKEY 3 4 2 1Update Figure9 Timing of turn off system using PWRKEY 4 2Update the Table25 SIM900D conducted RF receive sensitivity 3 8 Modify the VRTC pin connection when backup is not needed 2 1 3 3 3 4 Modify the power supply range from 3 4V 4 5V to 3 1V 4 8V 3 4 1 1Update the Figure Timing of turn on system using PWRKEY Modify the power supply range 3 2V 4 8V 3 3 2 Add Fi2. 38 4 13 General Purpose Input Output 39 a EB S 39 4D Ancia IC AC E 40 5 Electrical Reliability and Radio Characteristics A 2Z 41 5 1 Absolute Maximum 41 5 2 Recommended Operating Conditions iier rtr rettet etr aaraa aaa aa aa 41 5 3 Digital Interface Characteristics 41 5 4 SIM Card Interface Characteristics e essetis eene eene eene enne nennen nennen 41 5 5 SIM VDD EG es nio EN S RA 42 5 6 AEG SI IN NC NOU m 42 5 7 Current Consumption CV BAT 5 8 V 42 5 6 Electro Static Discharges a 43 5 9 Radio Bi ze dic Uo PIRE u Z DS D Rm 44 591 Maolil Output Power u u uuu yu uuu aaa asuaka qaquq 44 592 Module RE R celve SensiliVIIVu u idiots uio R saus ui ena d du paene 45 5 93 Module Operating Frequencie esyw 9 46 MID Ere IRR 47 6 1 Topand Bortom View o
3. 4 19 FIGURE 11 POWERED ON DOWN MODULE USING TRANSISTOR 1 nnns 20 FIGURE 12 POWERED ON DOWN MODULE USING BUTTON eran n nnn nnns 20 FIGURE 13 TIMING OF POWER ON e eee Nene 20 FIGURE 14 TIMING OF POWER DOWN SIM900D BY PWRKEY 21 FIGURE 15 TIMING OF RESTART SIM900D 23 FIGURE 16 SIM900D WITH BATTERY CHARGER AND PACK CONNECTION 25 FIGURE 17 RTC SUPPLY FROM 28 FIGURE 18 RTC SUPPLY FROM NON CHARGEABLE BATTERY yo Ql 28 FIGURE 19 RTC SUPPLY FROM RECHARGEABLE BATTERY 29 FIGURE 20 SEIKO XHA414H IVOIE CHARGE DISCHARGE CHARACTERISTIC 29 FIGURE 21 CONNECTION OF THE SERIAL INTERFACES L M N A 29 FIGURE 22 CONNECTION OF RXD AND TXD ONLY amp W RyZ 30 FIGURE 23 CONNECTION FOR SOFTWARE UPGRADING AND DEBUGGING 31 FIGURE 24 SPEAKER REFERENCE C
4. A company of SIM Tech SIM900D Hardware Design V2 02 Smart Machine Smart Decision Document Title SIM900D Hardware Design Version 2 02 2012 05 07 Document Control ID SIM900D Hardware Design V2 02 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 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 Wireless Solutions Ltd 2012 SIM900D Hardware D
5. 47 6 2 Typical Solder Reflow Profll 47 ESSLE E I D E MO A E E E A E A E E 48 l 75 ul E E 48 B Terms and A amp bWeviatsons 49 C 2 74 35 50 SIM900D_Hardware Design_V2 02 4 2012 05 07 lt 929 Smart Machine Smart Decision Table Index TABLE 1 SIM900D KEY 6 8 TABLE 2 CODING SCHEMES AND MAXIMUM NET DATA RATES OVER AIR 10 TABLE 3 OVERVIEW OF OPERATING 10 TABLE 4 PIN DESCRIPTION 14 TABLE 5 THE CURRENT CONSUMPTION OF MINIMUM FUNCTIONALITY 23 TABLE 6 SPECIFICATION OF RECOMMENDED BATTERY 26 TABLE 7 CHARGE OPERATING 6 27 TABLE 8 AT COMMAND USUALLY USED CHARGE ONLY 27 TABLE 9 MICROPHONE INPUT CHARACTERISTICS 33 TABLE 10 AUDIO OUTPUT CHARACTERISTICS etes 34 TABLE 11 PIN DESCRIPTION AMPHENOL SIM CARD HOLDER
6. uu sassa qaa EROAA ERRES 21 4 2 2 1 Power down SIM900D by Pin 2 4 2 2 2 Power down SIM900D by Command 21 4 2 2 3 Over voltage Under voltage Power down 22 4 2 2 4 Over temperature or Under temperature Power down 22 4 2 5 Restart SIM90DDAN PWRKEY uu L 22 4 3 Power AI 23 431 Minimum Functionality 23 43 2 SleemyNde J AT CSCLK 1 23 433 AVake Up SIM900D from Sleep Mode 1 AT CSCLK 1 24 J oh 2 AV C5SC LEND a asa QU ISI e HU IUE 24 4 3 5 Wake Up SIM900D from Sleep Mode 2 AT CSCLK 2 24 4 4 Cu uu uuu RT 24 Battery 25 AAD Recommended battery Park sesiet l l l l l Gr estet
7. 8 4 73 Earphone Interface Configuration The lines in bold type should be accorded to differential Smart Machine Smart Decision signal layout rules ESD x ANTI ro MODULE TuF SPK2P E EL 33pF 10pF ESD Tub 33pF 33pF ANT ae zs qui L 9001 8905 050 Figure 27 Earphone reference circuit 4 7 4 Audio Electronic Characteristics Table 9 Microphone Input Characteristics Parameter Min Typ Max Unit Working Voltage 1 5 2 0 V Working Current 200 500 uA External Microphone Load Resistance 162 22 kQ Internal biasing DC Characteristics pus V Differential input THD lt 1 at 159 mVrms voltage F 1KHz pre amp gain 20 dB PGA gain 14 dB THD lt 5 at 740 mVrms F 1KHz pre amp gain 0 dB PGA gain 0 dB SIM900D_Hardware Design_V2 02 33 2012 05 07 B of SIM Tech Smart Machine Smart Decision Table 10 Audio Output Characteristics Parameter Conditions Min Unit 320 91 THD 0 1 320 96 mW THD 1 Normal Output swing Output SPK Voltage 1 1 Vpp single ended Output swing Voltage 22 Vpp differential 4 8 SIM Card Interface 4 8 1 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
8. 5 7 Current Consumption VBAT 3 8V Table 23 Current consumption SIM900D_Hardware Design_V2 02 A company of SIM Tech Smart Machine Smart Decision BS PA MFRMS 5 1 2 BS PA MFRMS 2 1 5 GSM 850 EGSM 900 Idle mode 27 mA DCS 1800 PCS 1900 PCL 5 250 GSM 850 5 EGSM 900 PCL 19 80 Volce call mA PCL 0 175 DCS 1800 s PCS 1900 PCL 15 75 PCL 5 240 GSM 850 m m my EGSM 900 Data mode PCL 19 88 GPRS 1Rx 1Tx PCL 0 170 DCS 1800 5 1900 2S PCL 15 80 PCL 5 270 GSM 850 a EGSM 900 BEER z Data mode PCL 19 125 GPRS 4Rx 1Tx PCL 0 205 DCS 1800 T v me PCS 1900 E BOLES 119 ECES 450 GSM 850 a m EGSM 900 Data mode PCL 19 143 GPRS 3Rx 2Tx PCL 0 300 DCS 1800 i m PCS 1900 DETT d PCL 15 126 Peak current During Tx burst p A n above table the current consumption value 15 the typical one of the module tested in laboratory In the mass production stage there may be differences among each individual 5 8 Electro Static Discharge SIM900D is an ESD sensitive 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 24 The ESD characteristics Temperature 25 Humidity 45 Pin Contact discharge Air discharge VBAT 5KV 10KV SIM900D_Hardware Design_V2 02 43 2012 05 07 A company of SIM Tech Smart
9. be set by AT command AT CBAND For details please 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 C Restricted operation 40 C 30 C and 80 C 85 C 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 Antenna pad 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 DBG_TXD Can be used for debugging and upgrading firmware
10. 25 443 Implemented charging 9 26 444 Operating modes during 27 CMAP OCC ie Quite MIS NER unan 28 4 5 Jl j ns s S 28 4 6 29 4 6 1 Function of Serial Port and Debug 30 20 2 Sorlware Upgrade and De WU a 31 AI TU E DICES ote 31 SIM900D_Hardware Design_V2 02 3 2012 05 07 gt gt 3 2 m E Smart Machine Smart Decision A vA Speaker Interlace uuu l 32 472 Microphone Interfaces Configuration s 32 AJo Earphone Interlace Oni Oral Oi ig eoe aea cento a ee E R E E 33 4 24 Aqudio Electronic Character Stes icc sncccacsaiateadsainaneadstinaidatncuphdeandetedechentecacndaladeetindbceeetajetecteathdenedstetesnentss 33 4 8 ill MAMA Nm 34 Aor E L Su eee 34 482 Design Considerations for SIM Card Holder 35 4 9 LCD Display SPI 37 ADO 37 DITO l On 000 AEA 37
11. Following 15 the specification of recommended battery pack SIM900D Hardware Design V2 02 23 2012 05 07 eo of SIM Tech Smart Machine Smart Decision Table 6 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 050V Max Charge Current 1 0C Charge Method CC CV Constant Current Constant Voltage Max Discharge Current 1 0C for continuous discharging mode Discharge Cut off Voltage 3 0V cell Internal resistance Initial lt 130mQ 4 4 3 Implemented charging technique SIM900D has battery charging function There are three pins related to the battery charging function 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 SIM900D module to battery when charging is in fast charge state The VBAT gives out charging current from SIM900D module to external battery TEMP BAT Pin is for user to measure the battery temperature Just let this Pin open if battery temperature measurement is not your concern So it is very simple to implement charging technique user just needs to connect the charger to the Pin and connect the battery to the VBAT Pin SIM900D battery charging happens after detecting charger supply and the battery pre
12. tt Cv IF 0 8E Le 9 SE EUM Beem DBG RXD T lt DBG TXD IN RXD TXD STATUS SIM DATA SIM SIM RST SIM900D TOP VIEW SIM VDD _9 KBRO 10 RI 11 PWRKEY 12 DISP CLK 13 DISP DATA 14 VRTC 15 DISP D C 16 GND 17 lt dDXMds NI3dS NCNdS dCOIN 81 NCOIIN 61 0 Ic 4 2145 9 8c 00dV 6 0 dWH lL Figure 2 SIM900D pin diagram Top view SIM900D_Hardware Design_V2 02 13 2012 05 07 ee company of SIM Tech 3 2 Pin Description Smart Machine Smart Decision Table 4 Pin description VBAT 38 39 I Power supply It is recommended to VRTC 15 Power supply for connect with a battery or a capacitor e g 4 7uF AGND 22 Analog GND 17 30 31 32 GND 34 35 36 37 Ground 48 PWRKEY should be pulled low at least PWRKEY 12 I 1 second and then released to power Pulled up internally on down the module Differential audio input MICIN 20 SPK1P 23 Differential audio output SPKIN 24 If these pins are unused MIC2P 18 keep open I Differential a
13. 5 3 E m E 209999 5 3 8 Smart Machine Smart Decision Power down Delay gt 800mS Restart a gt a gt gt PWRKEY N STATUS N x Figure 15 Timing of restart SIM900D 43 Power Saving Mode SIM900D have two sleep modes sleep mode 1 is enabled by hardware DTR sleep mode 215 only enabled by sertal port regardless of the DTR In sleep mode the current of module 15 very low The command AT CFUN lt fun gt be used to set SIM900D into minimum functionality When SIM900D 15 in sleep mode and minimum functionality the current of module is lowest 4 3 1 Minimum Functionality Mode There are three functionality modes which could be set by the AT command A T 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 SIM900D is set to minimum functionality by AT CFUN 0 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 the AT Command AT CFUN lt fun gt please refer to document 1 Table 5 The Curre
14. Then it is changed to high For more details please refer to document 7 SIM900D_Hardware Design_V2 02 37 2012 05 07 Qeeee O 7i Smart Machine Smart Decision The behavior of the RI pin Is shown in the following figure when the module is used as receiver RI HIGH Establish the call Hang up the call Idle Ring Figure 32 RI behaviour of voice calling as a receiver RI HIGH Establish the call Hang up the call Idle Ring Figure 33 RI behaviour of data calling asa receiver HIGH i 120mS LOW Idle Receive SMS URC Figure 34 RI behaviour of URC or receive SMS However if the module is 5 caller the RI will remain high Please refer to the following figure HIGH LOW x Idle Ring Establish Hang up Idle the call the call Figure 35 RI behaviour as a caller 4 12 Network Status Indication The NETLIGHT pin can be used to drive a network status indication LED The status of this pin is listed in following table SIM900D_Hardware Design_V2 02 38 2012 05 07 eo of SIM Tech Smart Machine Smart Decision Table 15 Status of the NETLIGHT pin Status SIM900D behavior Off SIM900D 15 not running 64ms On 800ms Off SIM900D not registered the network 64ms On 3000ms Off SIM900D registered to the network 64ms On 300ms Off GPRS communication is established A reference circuit is recommended in the following figu
15. network Only afew AT commands is available 50 IMPORTANT Charge only mode 15 as listed below S charging when power down it means that not all software tasks are running Note VBAT can not provide more than 5mA current while SIM900D 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 SIM900D DDLO charging state occurs Table 8 AT Command 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 SIM900D_Hardware Design_ V2 02 27 2012 05 07 gt 3 E m E 20095999 5 3 8 Smart Machine Smart Decision can be transferred from Charge only mode to Charging in normal mode In Charge only mode the default value 15 0 4 45 Charger requirements Following 15 the requirements of charger for SIM900D Simple transformer power plug Output voltage 5 0V 6V Minimum supply current 750mA 10V peak voltage is allowed for maximum 1ms when charging current is switched off A 1 6A peak current is allowed for maximum 1115 when charging current is switched on 45 RTC Backup Current input for RTC when the VBAT 15 not supplied for the system Current output for backup battery wh
16. 270 OHM ON TVS101 i cioe 02 ON 2 4 p102 Cio3 104 E SMBJ15A 100uF a 330uF 400nF MBR360 I 1 Figure 8 Reference circuit of the DC DC power supply The single 3 6V Li ion cell battery can be connected to SIM900D 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 VBAT bypass capacitor Ca 100uF tantalum capacitor ESR 0 7Q Another VBAT bypass capacitor SIM900D Hardware Design V2 02 18 2012 05 07 gt 3 E 3 5 209999 5 8 Smart Machine Smart Decision 577u8 4615mS m gt E Burst 2A VBAT VBAT Max 300mV Figure 9 VBAT voltage drop during transmit burst 411 Minimizing Voltage Drop of When designing the power supply user s application pay special attention to power losses that the input voltage never drops below 3 1 V even when current consumption rises to 2A in
17. Charging 15 stopped when the charging current at constant voltage has decreased down to the pre set current 4 4 4 Operating modes during charging The battery can be charged during various operating mode That means that charging can be in progress while SIM900D is in Normal mode SLEEP IDLE TALK GPRS IDLE 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 connects to the module s VCHG Pin and the battery is connected to the VBAT Pin while SIM900D 15 in POWER DOWN mode SIM900D will go into the Charge only The following table gives the difference between Charge mode and Charge only mode Table 7 Charge operating modes How to activate mode Features Connect charger to module s VCHG GSM remains operational and registers and connect battery to VBAT Pin of GSM network while charging is in module while SIM900D is in Normal progress 3 operating mode including The serial interfaces are available in 2 IDLE TALK mode SLEEP mode etc IDLE TALK mode the AT command set can be used fully in this case 5 In SLEEP mode the serial interfaces are not available Once the serial port 1s connected and there is data in transfer SIM900D will exit the SLEEP mode Connect charger to module s Pin Battery be charged when GSM while SIM900D is in POWER DOWN engine 15 not registered to GSM mode
18. Machine Smart Decision 5 9 Radio Characteristics 5 9 1 Module RF Output Power The following table shows the module conducted output power 1t 1s followed by the 3GPP TS 05 05 technical specification requirement Table 25 SIM900D GSM 900 and GSM 850 conducted RF SIM900D_Hardware Design_V2 02 44 2012 05 07 A company of SIM Tech Smart Machine Smart Decision Table 26 SIM900D DCS 1800 and PCS 1900 conducted RF output power 550 band the module 15 a class 4 device so the module s output power should not exceed 33dBm and at t condition and At band the module is class 1 device so the module s output power should not exceed im power level the output power tolerance should not exceed 2dB under normal der extreme condition 30dBm and at the maximum power level the output power tolerance should not exceed 2dB under normal condition and 2 5dB under extreme condition 5 9 2 Module RF Receive Sensitivity The following table shows the module s conducted receive sensitivity it is tested under static condition SIM900D Hardware Design V2 02 45 2012 05 07 00 A company of SIM Tech Smart Machine Smart Decision Table 27 SIM900D conducted receive sensitivity GSM850 109dBm 107dBm EGSM900 109dBm 107dBm DCS1800 109dBm 107dBm PCS1900 109dBm 107dBm 5 9 3 Module Operating Frequencies The following table shows the module s opera
19. RST 22R e RST VPP MODULE CLK IO 10M 122 SIM DATA C707 10M006 5 I SMF05C 1 Figure 29 Reference circuit of the 6 SIM holder 4 8 2 Design Considerations for SIM Card Holder For 6 pin SIM card holder SIMCom recommends to use Amphenol C707 10M006 5122 User can visit http www amphenol com for more information about the holder CARD Tb Nd 17 11 Mix NI 2 80 BETJERMI DON PT POS PATA A MNC re MAE EW Bet Figure 30 Amphenol 707 10M006 5122 SIM card holder SIM900D_Hardware Design_V2 02 35 2012 05 07 B pere Smart Machine Smart Decision Table 11 Pin description Amphenol SIM card holder Pinname Signal Description el SIM_VDD SIM card power supply C 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 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 e N 2 5 1 4 3 0 FULL STROKE 2 0 SDA 91228 F 2 54 PITCH 0 4 REF HSG EDGE RECOMMENDED PCB LAYOUT xl m NOTES i SEE PRODUCT SPECIFICATION PS 99020 007 2 PACKING TAPE AMD REEL FOR DETAIL SEE SDA 8I228 9800 SHT 3 PUSH R DZLEVER MUST NOT PROTRUDE m BEYOND HOUSING EDGE IM THIS AR
20. Support phonebook types SM FD LD RC ON MC GSM 11 14 Release 99 support RTC Size 33 33 3mm Weight 6 2g SIM900D Hardware Design V2 02 9 2012 05 07 e Smart Machine Smart Decision Firmware upgrade Firmware upgradeable by debug port SIM900D does work at this temperature but some radio frequency characteristics may deviate from the GSM specification Table 2 Coding schemes and maximum net data rates over air interface Coding scheme 1 timeslot CS 1 9 05kbps CS 2 13 4kbps CS 3 15 6kbps CS 4 21 4kbps 2 2 Operating Modes 2 timeslot 4 timeslot 18 1kbps 36 2kbps 26 8kbps 53 6kbps 31 2kbps 62 4kbps 42 8kbps 85 6kbps The table below summarizes the various operating modes of SIM900D Table 3 Overview of operating modes Mode Function GSM GPRS SLEEP GSM IDLE Normal GSM operation TALK GPRS STANDBY GPRS DATA 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 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 Software is active Module registered to the GSM network and the module is ready to communicate Connection between two subscribers 15 in progress In this case the power consumption depends on network settings such
21. as DTX off on FR EFR HR hopping sequences antenna 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 There is GPRS data transfer PPP or TCP or UDP in progress In this case 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 Normal power down by sending the AT command AT CPOWD 1 or using PWRKEY Power down 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 Minimum AT command A T CFUN can be used to set the module to a minimum functionality mode SIM900D_Hardware Design_V2 02 10 2012 05 07 ee Tech functionality mode Charge only mode Charge mode during normal operation Smart Machine Smart Decision 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
22. 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 x communication systems Forget to think much of these instructions may lead to the flight safety 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 4 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 guarantee
23. figure the is NTC thermistor MURATA 15 is recommended to use Its impedance 15 10Kohm at 25 C Please refer to the above figure for the reference circuit 4 41 Battery pack characteristics SIM900D 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 cost more time for charging The 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 battery pack including protection circuit should be as low as possible Its recommended value doesnot exceed 150mQ The battery pack must be protected from reverse pole connection It is recommended that the battery pack user integrated into the application is compliant with these specifications The battery pack compliant with these specifications is also important for the AT command 1 100 percent of remaining battery capacity returned by AT CBC is related to battery capacity On the SIM900D the build in circuit of the power management chipset monitors the supply voltage constantly Once the Under voltage 15 detected the SIM900D will be powered down automatically 4 4 Recommended battery pack
24. interrupts such as GPIO interrupt SIM900D will enter sleep mode 2 automatically In this mode SIM900D can still receive paging or SMS from network but the serial port 15 not accessible Note For SIM900D It is requested to set AT command AT CSCLK 2 to enable the sleep mode 2 the default value is 0 which not make the module to enter sleep mode For more details please refer to document 1 4 3 5 Wake Up SIM900D from Sleep Mode 2 AT CSCLK 2 When SIM900D is in sleep mode 2 AT CSCLK 2 the following methods can wake up the module Send data to SIM900D via main serial port Receive a voice 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 SIM900D has integrated a charging circuit inside the module for Li Ion batteries charging control which make it very convenient for applications which support battery charging A common connection is shown in following figure SIM900D_Hardware Design_V2 02 24 2012 05 07 gt 5 3 E m E 209999 5 3 8 Smart Machine Smart Decision 5 V V BAT Module Battery Pack TEMP BAT Thermistor Figure 16 SIM900D with battery charger and pack connection Battery temperature measurement is a customization function which 15 supported by the software the module In above
25. supported The SIM interface 15 powered from internal regulator in the module It is recommended to use an ESD protection compon nt such as ST www st com ESDA6VIWS 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 15 illustrated In the following figure VDD EXT 100nF MOLEX 91228 SIM RST RST VPP MODULA w CLK VO T KERO i PRESENCE GND SIM DATA Jm CARD SMF05C Figure 28 Reference circuit of the 8 SIM holder The SIM PRESENCE pin 15 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 is illustrated in the following figure SIM900D_Hardware Design_V2 02 34 2012 05 07 gt o 3 m be S O i 5 5 Smart Machine Smart Decision 100nF _ SIM CARD SIM_VDD VCC GND SIM
26. systematically enter Charge only mode when a charger and battery are connected to a switched off SIM900D In the mode the module does not search for network and has limited AT commands available The module also can enter Charge only mode from Charge mode during normal operation by normally shutdown the module The module will automatically go to this mode when a charger is connected to a Normal operation mode module of which battery voltage is not lower than 3 2V Normal operation mode includes SLEEP IDLE TALK GPRS IDLE and GPRS DATA 2 3 SIM900D Functional Diagram The following figure shows a functional diagram of SIM900D The GSM baseband engine Flash The GSM radio frequency part The antenna interface The other interfaces SIM900D_Hardware Design_V2 02 11 2012 05 07 RE Smart Machine Smart Decision Acompany of SIM Tech Serial Interface Debug upgrading program Power Amplifier Controller ith PMU I 32 768KHz SIM interface Digital Baseband e o e PWRKEY Analog interface Figure 1 SIM900D functional diagram SIM900D_Hardware Design_V2 02 12 2012 05 07 995 Smart Machine Smart Decision 3 Package Information 3 1 Pin out Diagram lt lt g vas oo 9 gt 5 2 2 Z 358 c 2256566 64 6 8 Ly
27. t eren 36 TABLE 12 PIN DESCRIPTION MOLEX SIM CARD HOLDER cere e eene 36 TABLE 13 ADC SPECIFICATION aaa re entente 37 TABLE 14 RI BEHAVIORS tette 37 TABLE 15 STATUS OF THE 39 TABLE 16 PIN DEFINITION OF THE GPIO INTERFACE ertt rnnt tente 39 TABLE 17 ABSOLUTE MAXIMUM RATINGS I nn tr De e 41 TABLE 18 RECOMMENDED OPERATING CONDITIONS rete eret 41 TABLE 19 DIGITAL INTERFACE 6 5 0 41 TABLE 20 SIM CARD INTERFACE CHARACTERISTICS 42 TABLE 21 SIM VDD 6 1 Nee tette tette tete ns 42 TABLE 22 VRTC CHARACTERISTICS 42 TABLE 23 CURRENT nn nn 42 TABLE 24 THE ESD CHARACTERISTICS TEMPERATURE 25 C HUMIDITY 45 94 43 TABLE 25 SIM900D GSM 900 AND GSM 850 CONDUCTED RF OUTPUT POWER 44 TABLE 26 SIM900D DCS 1800 AND 5 1900 CONDUCTED RF OUTPUT POWER 45 TABLE 27 SIM900D CONDUCTED RF RECEIVE SENSITIVITY ettet 46 TABLE 28 SIM900D OPERATING 5 46 TABLE 29 RE
28. 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 indicated by STATUS pin which is at low level at this time 4 2 2 2 Power down SIM900D by AT Command SIM900D 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 15 at low level at this time SIM900D Hardware Design V2 02 21 2012 05 07 B of SIM Tech Smart Machine Smart Decision For detail about the AT command AT CPOWD please refer to document 1 4 2 2 3 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 3 2V 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 fo
29. thetransmtt 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 IC and the bypass capacitor should be placed to the module as close as possible VBAT MIN 3 IV meme AC EIN neci eme Figure 10 The minimal VBAT voltage requirement at VBAT drop 4 1 2 Monitoring Power Supply The AT command AT CBC 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 SIM900D 4 2 1 1 Turn on SIM900D Using PWRKEY Pin Power on User can power on SIM900D by pulling down the PWRKEY pin for at least 1 second and release This pin 15 already pulled up to 3V in the module internal so external pull up is not necessary Reference circuit is shown as below 3V 100K PWRKEY Power on down logic 4 7K Turn on off impulse 47K MODULE W SIM900D Hardware Design V2 02 19 2012 05 07 gt 5 3 E m E 209999 5 3 8 Smart Machine Smart Decision Figure 11 Powered on down module using transistor Power on down logic MODULE Figure 12 Powered on down module using button The power on scenarios 15 illustrated as followin
30. 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 telecommunications system Phase 2 Alphabets and language specific information Mobile Station Part 1 Conformance specification Digital cellular telecommunications system Phase 2 MS conformance specification 48 2012 05 07 00 Soc Com oer Smart Machine Smart Decision B Terms and Abbreviations Table 30 Terms and Abbreviations SIM900D Hardware Design V2 02 2012 05 07 ee ech Smart Machine Smart Decision 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 calls missed calls ON SIM or own numbers MSISDNs list RC Mobile Equipment list of received calls SM SIM phonebook NC Not connect C Safety Caution Table 31 Safety caution Requirements When in hospital or other health care
31. EA 5 1 4 TAILS EACH SIDE OF CONNECTOR LIE ss WITHIN OQ lzmm OF EACH OTHER 26 0 REF 31 00 20 15 ITEM COMPONENT MATERIAL w HOUSING L S302 GLASS FILL ULS4 v O COLOUR BLACK er TERMINAL 0 PHOSPHOR BRONZE D lum MIN OVER on IN CONTACT AREA 2 MIN Sa OM SMT TAILS CRYSTAL POLYMER LCP PUSH BUTTON GF NYLON 46 YELLOW MY COIL SPRING Pusu 1 0 4 STAINLESS STEEL Xy fern 1 jSTEEL N LEVER 0 4 STAINLESS STEEL 2 5 THIRD ANGLE PROJECTION co REVISE _ ONLY ON CAD SYSTEM Pm Tun awana SETAC TYP CONT HEIGHT BHEE MUT NE MITHIRIT BEETTLM SIM PCB CONNECTOR OTE iar MOLEX EUROPE MOLEX EUROPE m n PNTT lo sree More 91228 po nm 91228 D IQ 0 0 0 3 X RO amp Figure 31 Molex 91228 SIM card holder Table 12 Pin description Molex SIM card holder Pin name Signal Description Cl SIM VDD SIM card power supply e SIM RST SIM card reset C3 SIM CLK SIM card clock C4 GND Connect to GND SIM900D_Hardware Design_V2 02 36 2012 05 07 gt o 3 E m 5 ecce 3 8 Smart Machine Smart Deci
32. Hardware Design V2 02 20 2012 05 07 eo of SIM Tech Smart Machine Smart Decision please refer to Figure 13 Timing of power on module the SIM900D will power up and go into Charge mode during normal operation In this case SIM900D sends out result code as following From CHARGE ONLY MODE to NORMAL MODE In Charge mode during normal operation all operations and AT commands are available 4 2 2 Power down SIM900D SIM900D will be powered down in the following situations Normal power down procedure power down SIM900D by the PWRKEY pin Normal power down procedure power down SIM900D 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 SIM900D by the PWRKEY Pin User can power down SIM900D by pulling down the PWRKEY pin for at least 1 second and release Please refer to the power on circuit The power down scenario 15 illustrated in following figure 5S gt Pulldown gt 1S Delay gt 1 75 I I I PWRKEY a Input Logoff net STATUS Output Serial Port Active X Undefined Figure 14 Timing of power down SIM900D 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
33. IRCUL SW 32 FIGURE 25 SPEAKER WITH AMPLIFIER REFERENCE CIRCUIT 32 FIGURE 26 MICROPHONE REFERENCRCIRCOILTL 32 FIGURE 27 EARPHONE IRCUIL 33 FIGURE 28 REFERENCE CIRCUIT OF THE 8 PIN SIM CARD HOLDER 34 FIGURE 29 REFERENCE CIRCUIT OF THE 6 PIN SIM CARD HOLDER 35 FIGURE 30 AMPHENOL 707 10M006 5122 SIM CARD HOLDEFR 35 FIGURE 31 MOLEX 9128 NM CARD HOLDER 36 FIGURE 32 RI BEHAVIOUR OF VOICE CALLING AS RECEIVER 38 FIGURE 33 RFBEHAVIOUR OF DATA CALLING AS A RECEIVER 38 FIGURE 54 N BEMAVIOUR OF URC OR RECEIVE SMS 38 FIGURE 35 RI BEHAVIOUR ASA CALLER
34. LATED DOCUMENTS cccscsssssssecsesscsucsecseseesucsucsecsessesarsucsecsucsesatsussucsecsesatsussucsucsesansutsucsesstsateatsaeaeeaees 48 TABLE 30 TERMS AND nan Anan A AA Aaa anaran nenen 49 TABLE 31 SAFETY 00 50 SIM900D_Hardware Design_V2 02 5 2012 05 07 Smart Machine Smart Decision Figure Index FIGURE 1 SIM900D FUNCTIONAL DIAGRAM 17 FIGURE 2 SIM900D PIN OUT DIAGRAM TOP VIEW 13 FIGURE 3 SIM900D TOP MECHANICAL DIMENSIONS UNIT 16 FIGURE 4 SIM900D BOTTOM MECHANICAL DIMENSIONS UNIT MM 16 FIGURE 5 SIM900D SIDE MECHANICAL DIMENSIONS UNIT nnns 1 FIGURE 6 RECOMMENDED PCB DECAL UNIT MM 17 FIGURE 7 REFERENCE CIRCUIT OF THE LDO POWER SUPPLY 18 FIGURE 8 REFERENCE CIRCUIT OF THE DC DC POWER SUPPLY 18 FIGURE 9 VBAT VOLTAGE DROP DURING TRANSMIT BURST 19 FIGURE 10 THE MINIMAL VBAT VOLTAGE REQUIREMENT AT VBAT DROP
35. all hardware interfaces between the module and customers boards Serial port and debug port can help user easily develop user s applications Audio channel which includes two microphone inputs and two receiver outputs Programmable general purpose input and output The SPI display interface will give users the flexibility to develop customized applications SIM900D is designed with power saving technique so that the current consumption is as low as 1 0mA in sleep mode SIM900D 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 SIM900D Key Features Table 1 SIM900D key features Feature Implementation Power supply 3 2V 4 8V Power saving Typical power consumption in sleep mode is 1 0mA BS PA MFRMS 9 Frequency bands SIM900D Quad band GSM 850 EGSM 900 DCS 1800 PCS 1900 SIM900D Hardware Design V2 02 2012 05 07 gt o 3 E m 5 9999 gt 3 8 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 Smart Machine Smart Decision SIM900D can search the 4 frequency bands automatically The frequency bands also
36. between module and client DTE MODULE DCE CUSTOMER DTE Serial port Serial port1 TXD lt gt RXD RXD RTS o RTS CTS lt gt O CTS DTR 04 o DTR DCD lt o DCD RI gt O RING Debug port Serial port2 DBG_TX TXD lt gt RXD Figure 21 Connection of the serial interfaces SIM900D_Hardware Design_V2 02 29 2012 05 07 B of SIM Tech Smart Machine Smart Decision If only RXD and TXD are used in user s application other serial pins should be kept open Please refer to following figure MODULE DCE CUSTOMER DTE Serial port Serial port TXD lt gt TXD RXD lic eet RXD RIS co I13 RTS CTS Q CTS DTR gt DTR DCD o DCD RI RING Debug port Serial port2 aie NE s RX lt D RXD Figure 22 Connection of RXD and TXD only Note if sleep mode is need in this situation the user need to connect the DTR signal as well or only sleep mode2 can be used For details please refer to document 7 4 6 1 Function of Serial Port and Debug Port Serial port Full modem device Contains data lines TXD and RXD hardware flow control lines RTS and CTS status lines DTR 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 func
37. d 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 SIM900D Hardware Design V2 02 50 2012 05 07 A company of SIM Tech Smart Machine Smart Decision Contact us Shanghai SIMCom Wireless Solutions Ltd Add SIM Technology Building No 633 Jinzhong Road Changning District Shanghai P R China 200335 Tel 86 21 3235 3300 Fax 86 21 3235 3301 URL www sim com wm SIM900D_Hardware Design_V2 02 51 2012 05 07
38. ebugging 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 TXD TXD IN OUT O RxD Q U OUT IN TXD VBAT PWRKEY GND C Figure 23 Connection for software upgrading and debugging The serial port and the debug port support the CMOS level If user connects the module to the computer the level shifter should be added between the and DTE For details about software upgrading please refer to document 4 4 7 Audio Interfaces SIM900D provides two analog inputs MICIP IN MIC2P 2N which could be used for electret microphone The module also provides two analog outputs SPK1P IN 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 circu
39. en 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 backup External capacitor backup 3 Large capacitance Capacitor Figure 17 RTC supply from capacitor Non chargeable battery backup Non chargeable Backup Battery Figure 18 RTC supply from non chargeable battery e Rechargeable battery backup SIM900D Hardware Design V2 02 28 2012 05 07 gt 3 E m 5 ecce 2 5 8 Smart Machine Smart Decision Rechargeable Backup Battery Figure 19 RTC supply from rechargeable battery Coin type rechargeable battery is 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 Charge 3 3V 50uA 5hr RT CC CV Discharge 20uA cov 0V CC Voltage V 0 20 40 60 80 100 Capacity uAh Figure 20 Seiko XH414H IVO1E Charge Discharge Characteristic 4 6 Serial Interfaces SIM900D provides two unbalanced asynchronous serial ports One is 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
40. esign V2 02 2 2012 05 07 gt 3 E m 5 2095999 5 8 Smart Machine Smart Decision Contents di 3 7 I Introduction SN 8 PEE LUE ago u u E 8 2 1 SIM900D Key 8 2 2 Operaa 87412 RR RR amm 10 2 3 gt Ponctonal 11 NEL CUALES TT TTE Te m 13 3 J isi DIETS e CRETAE Tm 13 3 2 mh E 14 3 3 n 16 ZEE o0 DIN NICE T Tm 18 4 Pos ri NER uu cm 18 411 Voltage Dropot VBAT uu uuu u u uu u o Mp a et DO E HU E RE DO CL QOL REED 19 412 Monitoring Power Supply etg NN greenhouse sere pene sae san ese denen 19 4 2 Power on down Scenarios u 19 POS i UD Nc I qm m 19 4 2 1 1 Turn SIM900D Using the PWRKEY Pin Power on 19 4 2 1 2 Turn on the SIM900D using the VCHG 20 422 Powerdown SIM900D cu
41. fer to document 9 SIM900D_Hardware Design_V2 02 47 2012 05 07 3 ccoo Appendix A Related Documents Table 29 Related documents SN 1 2 3 4 5 7 8 9 10 11 12 13 14 Document name SIM900 AT Command Manual AN SIM900 TCPIP SIM900 Multiplexer User Manual Application Note AN SIM900 Series Update Tool UGD AN SIM900 AUDIO SIM900 Embedded AT Application Note AN Serial Port AN SIM900D 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 SIM900D_Hardware Design_V2 02 Smart Machine Smart Decision Remark SIM900 AT Command Manual TCP IP Applications User Manual SIM900 Multiplexer User Manual Application Note SIM900 Series Update Tool User Guide Applications Note About SIM900 Audio SIM900 Embedded AT Application Note Application Note About Serial Port Application Note About SIM900D 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
42. following table are stress ratings under non operating conditions Stresses beyond any of these limits will cause permanent damage to SIM900D Table 17 Absolute maximum ratings VBAT Power supply voltage V Vp Input voltage 0 3 3 1 V Ir Input current 10 mA Output current 10 mA These parameters are for digital interface pins such as GPIO LCD PWM and DEBUG 5 2 Recommended Operating Conditions Table 18 Recommended operating conditions VBAT Power supply voltage TOPER Operating temperature 40 25 85 C TsrG Storage temperature 45 90 53 Digital Interface Characteristics Table 19 Digital interface characteristics High level Input current Low level input current 10 10 uA High level input voltage 2 4 V Vit Low level input voltage 0 4 V Von High level output voltage Oe V VoL Low level output voltage 0 1 V These parameters are for digital interface pins such as GPIO UART LCD PWM and DEBUG 5 4 SIM Card Interface Characteristics SIM900D Hardware Design V2 02 41 2012 05 07 Smart Machine Smart Decision gt 8 3 s Table 20 SIM card interface characteristics 5 5 SIM VDD Characteristics Table 21 SIM VDD characteristics L F lt gt ot 5 6 VRTC Characteristics O Table 22 VRTC
43. g figure P Pulldown gt 1S Delay gt 2 25 VBAT gt Miu 2 4V PWRKEY N Vir lt 0 4V Input Vdis 2 7V x STATUS Output Serial Port Undefined X Active Figure 13 Timing of power on module When power on procedure is completed SIM900D 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 15 active Note User can use AT command 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 SIM900D is powered on For details please refer to the chapter AT IPR in document 1 4 2 1 2 Turn on the SIM900D using the VCHG signal The SIM900D will be automatically turned on when a charger is connected to the switched off SIM900D of which VBAT pin voltage is greater than 3 2V SIM900D 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 For detailed information please refer to chapter 3 5 When module is powered on using the VCHG signal SIM900D sends out result code as following when fixed baud rate set RDY CHARGE ONLY MODE When user drives the PWRKEY of Charge only mode SIM900D to a low level voltage for a period of time SIM900D
44. gure6 The minimal VBAT voltage at VBAT drop 3 4 Modified figure7 figure8 figurell 53 6 Add 3 6 4 and 3 6 5 description 3 11 1 Update the Figure25 53 7 Update the Figurel3 Arrange the structure of document Modify chapter6 Manufacturing Add illustration of SIM900 module information and some notes in chapter 5 Modify 56 Add some notes in chapter 5 Author Jing zhou Jing zhou Jing zhou Jing zhou Jing zhou Juntao zhao Juntao zhao 2012 05 07 gt 5 3 E m E 209999 5 3 8 Smart Machine Smart Decision 1 Introduction This document describes SIM900D hardware interface in great detail This document can help user to quickly understand SIM900D interface specifications electrical and mechanical details With the help of this document and other SIM900D application notes user guide users can use SIM900D to design various applications quickly 2 SIM900D Overview Designed for global market SIM900D 15 a quad band GSM GPRS module that works on frequencies GSM 850MHz EGSM 900MHz DCS 1800MHz and PCS 1900M Hz SIM900D features GPRS multi slot class 10 class 8 optional and supports GPRS coding schemes 5 1 5 2 CS 3 and CS 4 With a tiny configuration of 33 33 3mm SIM900D can meet almost all the space requirements in user applications such as M2M smart phone PDA FWP and other mobile devices SIM900D has 48 SMT pads and provides
45. it for audio National Semiconductor Company s LM4890 is recommended SIM900D Hardware Design V2 02 31 2012 05 07 i 995 oti Smart Machine Smart Decision 4 7 4 Speaker Interface Configuration These components should be placed to speaker as close as possible The lines in bold type should be accorded to differential ESD signal layout rules MODULE Figure 24 Speaker reference circuit These components should be placed to speaker as close as possible The lines in bold type should be accorded to differential signal layout rules lt 10pF 33pF y ESD SPOP Amplifier ANTI i Circuit MODULE SPK2N mer 10pF T 33pF AE Figure 25 Speaker with amplifier reference circuit 4 7 3 Microphone Interfaces Configuration K These components should be placed to microphone as close as possible i lines in bold type should 10pF 33pF s P p accorded to differential z ignal rul signal layout rules 1 Electret MODULE Microphone Figure 26 Microphone reference circuit SIM900D_Hardware Design_V2 02 32 2012 05 07 gt 3 E 3 5 2095999 5
46. llowing 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 15 at low level at this time 4 2 24 Over temperature or Under temperature Power down The module will constantly monitor the temperature of the module If the temperature gt 80 the following URC will be reported 1 If the temperature lt 30 following URC will be reported CMTE I If the temperature gt 85 the following URC will be reported and the module will be automatically powered down CMTE 2 If the temperature lt 40 the following URC will be reported and the module will be automatically powered down CMTE 2 At this moment AT commands can not be executed any more and only the RTC 1s still active Power down mode can also be indicated by STATUS pin which is at low level at this time The AT command could be used to read the temperature when the module is running For details please refer document 1 4 2 3 Restart SIM900D by PWRKEY Pin When the module works normally if the user wants to restart the module follow the procedure below 1 Power down the module 2 Walt for at least 800mS after STATUS pin changed to low level 3 Power on the module SIM900D Hardware Design V2 02 22 2012 05 07 gt
47. ns shows mm Figure 6 Recommended PCB decal Unit mm Note Keep copper out of area A B C Do not place via in area A B and C to avoid short circuit between via on customer board and the test points on the bottom side of the module SIM900D Hardware Design V2 02 17 2012 05 07 060 A company of SIM Tech 4 Application Interface Smart Machine Smart Decision 41 Power Supply The power supply range of SIM900D 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 uF is strongly recommended this capacitor should be placed as close as possible to SIM900D VBAT pins The following figure 15 the reference design of 5V input power supply The designed output for the power supply 15 4 1V thus a linear regulator can be used DC INPUT 0101 MIC29302 FB101 VB T 270 OHM Figure 7 Reference circuit of the LDO power supply 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 DC 9101 LM2596 ADJ L101 FB101 VBAT t vin Vout 2 e Y Y Y e 100uH
48. nt consumption of Minimum Functionality Mode lt fun gt Current consumption uA sleep mode 0 897 1 1306 4 967 4 3 2 Sleep Mode 1 AT CSCLK 1 User can control SIM900D module to enter or exit the sleep mode 1 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 SIM900D will enter sleep mode 1 automatically In this mode SIM900D can still receive paging or SMS from network but the serial port is not accessible SIM900D_Hardware Design_V2 02 23 2012 05 07 ee Tech Smart Machine Smart Decision Note For SIM900D it requests to set command AT CSCLK I 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 SIM900D from Sleep Mode 1 AT CSCLK 1 When SIM900D is in sleep mode AT CSCLK 1 the following methods can wake up the module Pull down DTR pin The serial port will be active after DTR pin 15 pulled to low level for about 50ms Receive a voice or data call from network Receive a SMS from network 4 3 4 Sleep Mode 2 AT CSCLK 2 In this mode SIM900D will continuously monitor the serial port data signal When there is data transfer over 5 seconds on the RXD signal and there is no on air and hardware
49. re MODULE VBAT NETLIGHT O Figure 36 Reference circuit of NETLIGHT 4 13 General Purpose Input Output GPIO SIM900D 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 A T SGPIO For more details please refer to document 1 Table 16 Pin definition of the GPIO interface Pin name Pin number Default function Second function Default state GPOI 40 GPIOI Output pull down KBRO 10 GPIO2 SIM card detection Output pull down 4 14 PWM SIM900D provides PWM which can be used to control a buzzer Features of buzzer PWM 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 PWM for 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 4 dB steps or it can be muted For details please refer to document 1 SIM900D_Hardware Design_V2 02 39 2012 05 07 ee ee A company of SIM Tech 4 15 Antenna Interface Smart Machine Smart Decision SIM900D provides a RF antenna inte
50. rface The customer s antenna should be located in the customer s main board and connect to module s antenna pad through microstrip line or other type RF trace which impendence must be controlled in 500 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 59 RFtestconnector O7 7 TG Matching circuit Antenna feed pad ANT 6 C C101 C102 L I Figure 37 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 tuning Usually matching components value is provided by antenna vendor the default value of 101 and R102 are 00 and reserve the place of C101 and C102 without soldering The RF test connector in above figure 15 used for conducted RF performance test and should be placed as close as possible to module s RF ANT pin 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 8 SIM900D_Hardware Design_V2 02 40 2012 05 07 e ee 5 Electrical Reliability and Radio Characteristics 2 Qeeee 209999 Smart Machine Smart Decision 5 1 Absolute Maximum Ratings The absolute maximum ratings stated In
51. sent If there is no charger supply or no battery present charging will not be enabled Normally there are three main states in whole charging procedure DDLO charge Pull up mode and UVLO charge Pre charge mode Fastcharge DDLO charge and UVLO charge DDLO 15 the state of battery when its voltage is under 1 5 V And UVLO means the battery voltage less than 3 3V and more than 1 5V The battery is not suitable for fast charging when its condition is DDLO or UVLO The SIM900D provides a small constant current to the battery when the battery is between DDLO and UVLO In DDLO charging SIM900D gives out 1 mA current to the battery And in UVLO charging SIM900D provides about less than 200mA current to the battery DDLO charging terminates when the battery voltage reaches 1 5 V UVLO charging terminates when the battery voltage 15 up to 3 3V Both DDLO and UVLO charge are controlled by the SIM900D hardware only Fast charge If there 15 a charger supply and battery present and the battery 15 not in DDLO and UVLO SIM900D will enter fast charge state Fast charge 15 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 SIM900D Hardware Design V2 02 26 2012 05 07 ee Tech Smart Machine Smart Decision 4 2V 15 reached
52. sion C5 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 SIM900D provides a serial LCD display interface It could also be used as SPI interface in the embedded application For details about embedded AT application please refer to document 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 4 10 ADC SIM900D provides an auxiliary ADC which can be used to measure the voltage User can use AT command AT CADC to read the voltage value For details of this AT command please refer to document 1 Table 13 ADC specification Parameter Min Unit Voltage range 0 2 8 V ADC Resolution 10 bits Sampling rate 200K Hz 4 11 RI Behaviors Table 14 RI Behaviors State RI response 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 pin will be changed to high 1 Establish the call 2 Hang up the call Data call ae The pin is changed to low and kept low for 120ms when a SMS is received Then it is changed to high mama The pin is changed to low and kept low for 120ms when some URCs are reported
53. ting frequency range it is followed by the 3GPP TS 05 05 technical specification requirement Table 28 SIM900D operating frequencies GSM850 869 894MHz 824 849 MHz EGSM900 925 960 72 880 915 DCS1800 1805 1880MHz 1710 1785MHz 51900 1930 1990MHz 1850 1910MHz SIM900D_Hardware Design_V2 02 46 2012 05 07 ee e ee 6 Manufacturing O Smart Machine Smart Decision 6 1 Top and Bottom View of SIM900D 1 E P8389 ju SIH909D 3 P N 4 54548 0172353 1 TYPE2 6 CE LOGO Figure 38 Top and bottom view of SIM900D These test points are only used for module manufacturing and testing They are not for customer using 6 2 Typical Solder Reflow Profile SIN900D x 0 100 200 Forecast 0 105 TIME SEC 211 RAMP SOAP Between 150 to 210 C Reflow 220 C Peak Temperature 1 14 7 99 4 31 53 8 38 14 4 1005 35 51 5 1596 re Ma Aw 14 5 101 4 38 544 44 H8 4g Different in Temp MP 3 14 7 99 4 31 53 8 38 2433 14 4 100 5 35 51 5 15 241 0 2 NP 1 14 5 101 4 38 54 4 44 2447 93 Different in Temp 0 04 1 99 365 ERE 4 Figure 39 Typical Solder Reflow Profile For details about secondary SMT please re
54. tion please refer to document 7 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 SIM900D 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 user must firstly send character A to synchronize the baud rate It is recommended to send AT until receives the response which means and DCE are correctly synchronized For more information please refer to the AT command AT IPR Restrictions of autobauding operation The DTE serial port must be set at 8 data bits no parity and stop bit URC such as RDY CFUN 1 and 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 CFUN 1 and CPIN READY will be reported when SIM900D is powered on Debug port SIM900D_Hardware Design_V2 02 30 2012 05 07 ee ee om Tech Smart Machine Smart Decision Used for d
55. udio input MIC2N 19 SPK2P 26 O Differential audio output SPK2N STATUS 5 Power status If these pins are unused NETLIGHT 41 O Network status keep open DISP CLK 13 DISP DATA 14 If these pins are unused Display interface DISP _D C 16 O keep open DISP CS 46 GPOI 40 VO GPIO If these pins are unused KBRO GPIO keep open This pin should be RXD 3 I Recetve data pulled to 3V externally TXD 4 O Transmit data If these pins are unused SIM900D_Hardware Design_V2 02 14 2012 05 07 Smart Machine Smart Decision gt 8 S 5 lt 122 5 Z Z SIM900D_Hardware Design_ V2 02 15 2012 05 07 Smart Machine Smart Decision 3 3 Package Dimensions Following shows the Mechanical dimensions of SIM900D top view side view and bottom view 2 Dimensions shows in mm Figure 3 SIM900D top mechanical dimensions Unit mm Figure 4 SIM900D bottom mechanical dimensions Unit mm SIM900 Hardware Design V2 02 7 2012 05 07 gt E m 5 S O i 5 3 8 Smart Machine Smart Decision C 05t0125 10050410 Figure 5 SIM900D side mechanical dimensions Unit mm FOOT PRINT RECOMMENDATION SIM900D Area First pad Keep nut Area B Keep out Area a A Keep out Area C Dimensio
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