SIM900R_Hardware Design_V1.
Smart Machine Smart Decision Document Title SIM900R Hardware Design Version 1.00 Date 2012-07-20 Status Release Document Control ID SIM900R_Hardware Design_V1.00 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.
Smart Machine Smart Decision Contents Contents.................................................................................................................................................................... 3 Version History ........................................................................................................................................................ 7 1 Introduction................................................................................................................
Smart Machine Smart Decision 4.13 4.14 4.15 4.16 4.17 General Purpose Input/Output (GPIO) ................................................................................................... 34 External Reset......................................................................................................................................... 34 PWM ......................................................................................................................................................
Smart Machine Smart Decision Table Index Table 1: SIM900R key features.............................................................................................................................. 8 Table 2: Coding schemes and maximum net data rates over air interface............................................................ 10 Table 3: Overview of operating modes ................................................................................................................ 10 Table 4: Pin description..
Smart Machine Smart Decision Figure Index Figure 1: SIM900R functional diagram ................................................................................................................11 Figure 2: SIM900R pin out diagram (Top view).................................................................................................. 12 Figure 3: Dimensions of SIM900R（Unit: mm）...............................................................................................
Smart Machine Smart Decision Version History Date Version Description of change Author 2012-07-20 1.00 Origin ZhouJing SIM900R_Hardware Design_V2.
Smart Machine Smart Decision 1 Introduction This document describes SIM900R hardware interface in great detail. This document can help user to quickly understand SIM900R interface specifications, electrical and mechanical details. With the help of this document and other SIM900R application notes, user guide, users can use SIM900R to design various applications quickly.
Smart Machine Smart Decision Temperature range z z z Normal operation: -30°C ~ +80°C Restricted operation: -40°C ~ -30°C and +80 °C ~ +85°C* Storage temperature -45°C ~ +90°C Data GPRS z z z z z 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.
Smart Machine Smart Decision Table 2: Coding schemes and maximum net data rates over air interface Coding scheme 1 timeslot 2 timeslot 4 timeslot CS-1 9.05kbps 18.1kbps 36.2kbps CS-2 13.4kbps 26.8kbps 53.6kbps CS-3 15.6kbps 31.2kbps 62.4kbps CS-4 21.4kbps 42.8kbps 85.6kbps 2.2 Operating Modes The table below summarizes the various operating modes of SIM900R.
Smart Machine Smart Decision 2.3 SIM900R Functional Diagram The following figure shows a functional diagram of SIM900R: z The GSM baseband engine z Flash z The GSM radio frequency part z The antenna interface z The other interfaces Figure 1: SIM900R functional diagram SIM900R_Hardware Design_V1.
Smart Machine Smart Decision GPIO12 GPIO11 STATUS GND GND GND GND GND RF_ANT GND GND VBAT VBAT VBAT GND GND NETLIGHT 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 Pin out Diagram PWRKEY 1 51 GPIO10 NC 2 50 GPIO9/KBC1 DTR 3 49 GPIO8/KBC2 RI 4 48 GPIO7/KBC3 DCD 5 47 GPIO6/KBC4 NC 6 46 GND CTS 7 45 GND RTS 8 44 GPIO5/KBR0 TXD 9 43 GPIO4/KBR1 RXD 10 42 GPIO3/KBR2 DISP_CLK 11 41 GPIO2/KBR3 DISP_DATA 12 40 GPIO1/KBR4 DISP_D/C
Smart Machine Smart Decision 3.2 Pin Description Table 4: Pin description Pin name Pin number I/O Description 55,56,57 I Power supply Comment Power supply VBAT VRTC 26 I/O Power supply for RTC It is recommended to connect with a battery or a capacitor (e.g. 4.7uF). VDD_EXT 15 O 2.8V output power supply If it is unused, keep open.
Smart Machine Smart Decision GPIO1/KBR4 40 GPIO1/keypad row 4 GPIO9/KBC1 50 GPIO9/keypad column 1 GPIO8/KBC2 49 GPIO8/keypad column 2 GPIO7/KBC3 48 GPIO7/keypad column 3 GPIO6/KBC4 47 GPIO6/keypad column 4 GPIO10 51 GPIO10 GPIO11 67 GPIO11 GPIO12 68 GPIO12 Serial port This pin should be pulled up to VDD_EXT externally.
Smart Machine Smart Decision 3.3 Package Dimensions BOTTOM VIEW TOP VIEW Figure 3: Dimensions of SIM900R（Unit: mm） Figure 4: Recommended PCB footprint outline（Unit: mm） Note: Keep copper out of area A. Do not place via in area B to avoid short circuit between the via on customer board and the test points on the bottom side of the module. SIM900R_Hardware Design_V1.
Smart Machine Smart Decision 4 4.1 Application Interface Power Supply GND The power supply range of SIM900R 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 µF is strongly recommended; this capacitor should be placed as close as possible to SIM900R VBAT pins. The following figure is the reference design of +5V input power supply.
Smart Machine Smart Decision Figure 7: VBAT voltage drop during transmit burst 4.1.1 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 3.1V even when current consumption rises to 2A in the transmit burst. If the power voltage drops below 3.1V, the module may be shut down automatically.
Smart Machine Smart Decision Figure 10: Powered on/down module using button The power on scenarios is illustrated as following figure. Figure 11: Timing of power on module When power on procedure is completed, SIM900R 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 “AT+IPR=x” to set a fixed baud rate and save the configuration to non-volatile flash memory.
Smart Machine Smart Decision Figure 12: Timing of power down SIM900R 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.
Smart Machine Smart Decision 4.2.2.4 Over-temperature or Under-temperature Power down The module will constantly monitor the temperature of the module, If the temperature > +80℃, the following URC will be reported: +CMTE: 1 If the temperature < -30℃, the following URC will be reported: +CMTE:-1 If the temperature > +85℃, the following URC will be reported, and the module will be automatically powered down.
Smart Machine Smart Decision z 0: minimum functionality. z 1: full functionality (default). z 4: flight mode (disable RF function). Minimum functionality mode minimizes the current consumption to the lowest level. If SIM900R 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.
Smart Machine Smart Decision 4.3.5 Wake Up SIM900R from Sleep Mode 2 (AT+CSCLK=2) When SIM900R is in sleep mode 2 (AT+CSCLK=2), the following methods can wake up the module: z Send data to SIM900R via main serial port. * z Receive a voice or data call from network. z Receive a SMS from network. * Note: The first byte of the user’s data will not be recognized. 4.4 RTC Backup Current input for RTC when the VBAT is not supplied for the system.
Smart Machine Smart Decision Coin-type rechargeable battery is recommended, such as XH414H-IV01E form Seiko can be used. Typical charge-discharge curves for this battery are shown in the following figure. Figure 17: Seiko XH414H-IV01E Charge-Discharge Characteristic 4.5 Serial Interfaces SIM900R 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).
Smart Machine Smart Decision MODULE (DCE) CUSTOMER (DTE) Serial port Serial port1 TXD TXD RXD RXD RTS RTS CTS CTS DTR DTR DCD DCD RI RING Debug port Serial port2 DBG_TX TXD DBG_RX RXD Figure 19: Connection of RXD and TXD only 4.5.1 Function of Serial Port and Debug Port Serial port: z Full modem device. z Contains data lines TXD and RXD, hardware flow control lines RTS and CTS, status lines DTR, DCD and RI. z Serial port can be used for CSD FAX, GPRS service and AT communication.
Smart Machine Smart Decision 4.5.2 Software Upgrade and Debug Refer to the following figure for debugging and upgrading software. Figure 20: 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 DCE and DTE. For details about software upgrading,please refer to document [4]. 4.
Smart Machine Smart Decision Figure 22: Speaker with amplifier reference circuit 4.6.2 Microphone Interfaces Configuration These components should be placed to microphone as close as possible ESD ANTI Electret Microphone 10pF 33pF 10pF 33pF The lines in bold type should be accorded to differential signal layout rules MIC_P MODULE MIC_N ESD ANTI 10pF 33pF Figure 23 : Microphone reference circuit Microphone input also could be used to LINE-IN input. For details, please refer to document [6].
Smart Machine Smart Decision 4.6.3 Earphone Interface Configuration Figure 24: Earphone reference circuit 4.6.4 Audio Electronic Characteristics Table 6: Microphone Input Characteristics Parameter Min Typ Max Unit Working Voltage 1.2 1.5 2.0 V Working Current 200 500 uA External Microphone Load Resistance 1.2 2.2 Internal biasing DC Characteristics Differential input voltage kΩ 2.5 V THD <1% at F=1KHz; pre-amp gain = 20 dB; PGA gain = 14 dB 15.
Smart Machine Smart Decision 4.7 4.7.1 SIM Card Interface 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 ) SMF05C.
Smart Machine Smart Decision 4.7.2 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.
Smart Machine Smart Decision Figure 28: Molex 91228 SIM card holder Table 9: Pin description (Molex SIM card holder) Pin name Signal Description C1 SIM_VDD SIM card power supply C2 SIM_RST SIM card reset C3 SIM_CLK SIM card clock C4 GND Connect to GND C5 GND Connect to GND C6 VPP Not connect C7 SIM_DATA SIM card data I/O C8 SIM_PRESENCE Detect SIM card presence 4.8 LCD Display/SPI Interface SIM900R provides a serial LCD display interface.
Smart Machine Smart Decision 4.9 Keypad Interface The keypad interface consists of 4 keypad column outputs and 5 keypad row inputs. The basic configuration is 4 keypad columns and 5 keypad rows, total 20 keys.
Smart Machine Smart Decision Table 11: ADC specification Parameter Min Typ Max Unit Voltage range 0 - 2.8 V ADC Resolution - 10 - bits Sampling rate - - 200K Hz 4.11 RI Behaviours Table 12: RI behaviours State RI response Standby High Voice call The pin is changed to low. When any of the following events occur, the pin will be changed to high: （1）Establish the call （2）Hang up the call Data call The pin is changed to low.
Smart Machine Smart Decision Figure 32: 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. Figure 33: RI behaviour as a caller 4.12 Network Status Indication The NETLIGHT pin can be used to drive a network status indication LED.
Smart Machine Smart Decision 4.13 General Purpose Input/Output (GPIO) SIM900R provides up to 12 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].
Smart Machine Smart Decision Figure 36: Reset reference design circuit NOTE: It is recommended to cut off the VBAT power supply directly instead of using external reset pin when SIM900R can not respond to the AT command “AT+CPOWD=1” and PWRKEY pin. 4.15 PWM SIM900R provides two PWMs which can be used to drive a vibrator, and a backlight LED for display or keyboard. Each PWM output frequency varies from 25.6KHz to 3.25MHz.
Smart Machine Smart Decision 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 R101 and R102 are 0Ω, and reserve the place of C101 and C102 without soldering. The RF test connector in above figure is used for conducted RF performance test, and should be placed as close as possible to the module’s RF_ANT pin.
Smart Machine Smart Decision 5 Electrical, Reliability and Radio Characteristics 5.1 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 SIM900R. Table 15: Absolute maximum ratings Symbol Parameter Min Typ Max Unit VBAT Power supply voltage - - 5.5 V VI Input voltage -0.3 - 3.
Smart Machine Smart Decision 5.4 SIM Card Interface Characteristics Table 18: SIM card interface characteristics Symbol Parameter Min Typ Max Unit IIH High-level input current -10 - 10 uA IIL Low-level input current -10 - 10 uA VIH High-level input voltage 1.4 - - V 2.4 - - V VIL Low-level input voltage - - 0.4 V 2.4 V VOH High-level output voltage VOL Low-level output voltage 5.5 1.7 - - V 2.7 - - V - - 0.1 V - - 0.
Smart Machine Smart Decision 5.7 VRTC Characteristics Table 21: VRTC characteristics Symbol Parameter Min Typ Max Unit VRTC-IN VRTC input voltage 2.00 3.00 3.15 V IRTC-IN VRTC input current - 2 - uA VRTC-OUT VRTC output voltage - 3.00 - V IRTC-OUT VRTC output current - 10 - uA 5.8 Current Consumption (VBAT = 3.8V) Table 22: Current consumption* Symbol Parameter Conditions Value Unit IVRTC VRTC current VBAT disconnects.
Smart Machine Smart Decision DCS 1800 IVBAT-peak Peak current During Tx burst PCL=19 130 PCL=0 300 PCL=7 155 PCL=15 122 mA 2 A * In above table the current consumption value is the typical one of the module tested in laboratory. In the mass production stage, there may be differences among each individual. 5.9 Electro-Static Discharge SIM900R is an ESD sensitive component, so more attention should be paid to the procedure of handling and packaging.
Smart Machine Smart Decision 8 27 ±3 ±4 9 25 ±3 ±4 10 23 ±3 ±4 11 21 ±3 ±4 12 19 ±3 ±4 13 17 ±3 ±4 14 15 ±3 ±4 15 13 ±3 ±4 16 11 ±5 ±6 17 9 ±5 ±6 18 7 ±5 ±6 19-31 5 ±5 ±6 Table 25: SIM900R DCS 1800 conducted RF output power DCS 1800 PCL Tolerance (dB) for conditions Nominal output power (dBm) Normal Extreme 29 36 ±2 ±2.
Smart Machine Smart Decision At DCS1800 band, the module is a class 1 device, so the module’s output power should not exceed 30dBm, and at the maximum power level, the output power tolerance should not exceed +/-2dB under normal condition and +/-2.5dB under extreme condition. 5.10.2 Module RF Receive Sensitivity The following table shows the module’s conducted receive sensitivity, it is tested under static condition.
Smart Machine Smart Decision 6 Manufacturing 6.1 Top and Bottom View of SIM900R Figure 38: Top and bottom view of SIM900R Note: These test points are only used for module manufacturing and testing. They are not for customer using. The following figure marked the information of SIM900R module.
Smart Machine Smart Decision 6.2 Typical Solder Reflow Profile Figure 40: Typical solder reflow profile For details about secondary SMT, please refer to document [10]. SIM900R_Hardware Design_V1.
Smart Machine Smart Decision Appendix A.
Smart Machine Smart Decision B.
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 MT calls (missed calls) ON SIM (or ME) own numbers (MSISDNs) list RC Mobile Equipment list of received calls SM SIM phonebook NC Not connect C.
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 SIM900R_Hardware Design_V1.
