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sim900b硬件参考设计资料

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    SIM900B的硬件设计参考资料。详细。

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    SIM900B_Hardware Design_V2.00 Smart Machine Smart Decision Document Title Version Date Status Document Control ID SIM900B Hardware Design 2.00 2011-04-11 Release SIM900B_Hardware Design_V2.00 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. SIMCom has not undertaken any independent search for additional relevant information, including any information that may be in the customer’s possession. Furthermore, system validation of this product designed by SIMCom within a larger electronic system remains the responsibility of the customer or the customer’s system integrator. All specifications supplied herein are subject to change. Copyright This document contains proprietary technical information which is the property of SIMCom Limited, copying of this document and giving it to others and the using or communication of the contents thereof, are forbidden without express authority. Offenders are liable to the payment of damages. All rights reserved in the event of grant of a patent or the registration of a utility model or design. All specification supplied herein are subject to change without notice at any time. Copyright © Shanghai SIMCom Wireless Solutions Ltd. 2011 SIM900B_Hardware Design_V2.00 2 2011-04-11 Smart Machine Smart Decision Contents Contents.................................................................................................................................................................... 3 Version History ........................................................................................................................................................ 7 1 Introduction....................................................................................................................................................... 8 2 SIM900B Overview........................................................................................................................................... 8 2.1 SIM900B Key Features ............................................................................................................................ 8 2.2 Operating Modes .................................................................................................................................... 10 2.3 SIM900B Functional Diagram ................................................................................................................11 3 Application Interface...................................................................................................................................... 12 3.1 Pin Description ....................................................................................................................................... 12 3.2 Power Supply.......................................................................................................................................... 14 3.2.1 Minimizing Voltage Drop of VBAT ................................................................................................... 15 3.2.2 Monitoring Power Supply ................................................................................................................... 15 3.3 Power on/down Scenarios ...................................................................................................................... 15 3.3.1 Power on SIM900B............................................................................................................................. 15 3.3.1.1 Turn on SIM900B Using the PWRKEY Pin (Power on) ..................................................................... 15 3.3.2 Power down SIM900B........................................................................................................................ 16 3.3.2.1 Power down SIM900B by the PWRKEY Pin ...................................................................................... 17 3.3.2.2 Power down SIM900B by AT Command ............................................................................................ 17 3.3.2.3 Over-voltage or Under-voltage Power down ....................................................................................... 17 3.3.2.4 Over-temperature or Under-temperature Power down ......................................................................... 18 3.3.3 Restart SIM900B by PWRKEY Pin.................................................................................................... 18 3.4 Power Saving Mode................................................................................................................................ 19 3.4.1 Minimum Functionality Mode ............................................................................................................ 19 3.4.2 Sleep Mode 1 (AT+CSCLK=1) .......................................................................................................... 19 3.4.3 Wake Up SIM900B from Sleep Mode 1 (AT+CSCLK=1)................................................................. 19 3.4.4 Sleep Mode 2 (AT+CSCLK=2) .......................................................................................................... 20 3.4.5 Wake Up SIM900B from Sleep Mode 2 (AT+CSCLK=2)................................................................. 20 3.5 RTC Backup ........................................................................................................................................... 20 3.6 Serial Interfaces ...................................................................................................................................... 21 3.6.1 Function of Serial Port and Debug Port .............................................................................................. 22 3.6.2 Software Upgrade and Debug ............................................................................................................. 23 3.7 Audio Interfaces ..................................................................................................................................... 23 3.7.1 Speaker Interface Configuration ......................................................................................................... 24 3.7.2 Microphone Interfaces Configuration ................................................................................................. 25 3.7.3 Earphone Interface Configuration....................................................................................................... 25 3.7.4 Audio Electronic Characteristics......................................................................................................... 25 3.8 SIM Card Interface ................................................................................................................................. 26 3.8.1 SIM Card Application ......................................................................................................................... 26 3.8.2 Design Considerations for SIM Card Holder ...................................................................................... 27 3.9 LCD Display/SPI Interface..................................................................................................................... 29 3.10 ADC........................................................................................................................................................ 30 3.11 RI Behaviors........................................................................................................................................... 30 SIM900B_Hardware Design_V2.00 3 2011-04-11 Smart Machine Smart Decision 3.12 Network Status Indication ...................................................................................................................... 31 3.13 General Purpose Input/Output (GPIO) ................................................................................................... 32 3.14 Keypad Interface .................................................................................................................................... 32 3.15 Buzzer..................................................................................................................................................... 33 4 Electrical, Reliability and Radio Characteristics......................................................................................... 34 4.1 Absolute Maximum Ratings................................................................................................................... 34 4.2 Recommended Operating Conditions..................................................................................................... 34 4.3 Digital Interface Characteristics ............................................................................................................. 34 4.4 SIM Card Interface Characteristics ........................................................................................................ 34 4.5 SIM_VDD Characteristics...................................................................................................................... 35 4.6 VRTC Characteristics ............................................................................................................................. 35 4.7 Current Consumption (VBAT = 3.8V) ................................................................................................... 35 4.8 Electro-Static Discharge ......................................................................................................................... 36 4.9 Radio Characteristics.............................................................................................................................. 37 4.9.1 Module RF Output Power ................................................................................................................... 37 4.9.2 Module RF Receive Sensitivity........................................................................................................... 38 4.9.3 Module Operating Frequencies ........................................................................................................... 39 5 Manufacturing ................................................................................................................................................ 40 5.1 Mechanical Dimensions of SIM900B .................................................................................................... 40 5.2 Mounting SIM900B onto the application platform ................................................................................ 41 5.3 Board-to-board connector....................................................................................................................... 41 5.4 Mechanical dimensions of the RUNFENG BB530-06001-20R............................................................. 42 5.5 RF connector .......................................................................................................................................... 43 5.6 Top View of the SIM900B...................................................................................................................... 44 5.7 PIN Assignment of SIM900B................................................................................................................. 45 Appendix ................................................................................................................................................................ 46 A. Related Documents.......................................................................................................................................... 46 B. Terms and Abbreviations ................................................................................................................................. 47 C. Safety Caution ................................................................................................................................................. 48 SIM900B_Hardware Design_V2.00 4 2011-04-11 Smart Machine Smart Decision Table Index TABLE 1: SIM900B 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 ....................................................................................................................................... 12 TABLE 5:THE CURRENT CONSUMPTION OF MINIMUM FUNCTIONALITY MODE ......................................... 19 TABLE 6: MICROPHONE INPUT CHARACTERISTICS ............................................................................................ 26 TABLE 7: AUDIO OUTPUT CHARACTERISTICS ...................................................................................................... 26 TABLE 8: PIN DESCRIPTION (AMPHENOL SIM CARD HOLDER)......................................................................... 28 TABLE 9: PIN DESCRIPTION (MOLEX SIM CARD HOLDER) ................................................................................ 29 TABLE 10: ADC SPECIFICATION ................................................................................................................................ 30 TABLE 11: RI BEHAVIORS ........................................................................................................................................... 30 TABLE 12: STATUS OF THE NETLIGHT PIN.............................................................................................................. 31 TABLE 13: PIN DEFINITION OF THE KEYPAD INTERFACE................................................................................... 32 TABLE 14: ABSOLUTE MAXIMUM RATINGS........................................................................................................... 34 TABLE 15: RECOMMENDED OPERATING CONDITIONS ....................................................................................... 34 TABLE 16: DIGITAL INTERFACE CHARACTERISTICS ........................................................................................... 34 TABLE 17: SIM CARD INTERFACE CHARACTERISTICS........................................................................................ 35 TABLE 18: SIM_VDD CHARACTERISTICS................................................................................................................ 35 TABLE 19: VRTC CHARACTERISTICS ....................................................................................................................... 35 TABLE 20: CURRENT CONSUMPTION ...................................................................................................................... 35 TABLE 21: THE ESD CHARACTERISTICS (TEMPERATURE: 25℃, HUMIDITY: 45 %) ....................................... 36 TABLE 22: SIM900B GSM 900 AND GSM 850 CONDUCTED RF OUTPUT POWER.............................................. 37 TABLE 23: SIM900B DCS 1800 AND PCS 1900 CONDUCTED RF OUTPUT POWER ............................................ 38 TABLE 24: SIM900B CONDUCTED RF RECEIVE SENSITIVITY............................................................................. 39 TABLE 25: SIM900B OPERATING FREQUENCIES.................................................................................................... 39 TABLE 26: PIN ASSIGNMENT...................................................................................................................................... 45 TABLE 27: RELATED DOCUMENTS ........................................................................................................................... 46 TABLE 28: TERMS AND ABBREVIATIONS................................................................................................................ 47 TABLE 29: SAFETY CAUTION..................................................................................................................................... 48 SIM900B_Hardware Design_V2.00 5 2011-04-11 Smart Machine Smart Decision Figure Index FIGURE 1: SIM900B FUNCTIONAL DIAGRAM......................................................................................................... 11 FIGURE 2: REFERENCE CIRCUIT OF THE LDO POWER SUPPLY ......................................................................... 14 FIGURE 3: REFERENCE CIRCUIT OF THE DC-DC POWER SUPPLY..................................................................... 14 FIGURE 4: VBAT VOLTAGE DROP DURING TRANSMIT BURST........................................................................... 15 FIGURE 5: THE MINIMAL VBAT VOLTAGE REQUIREMENT AT VBAT DROP .................................................... 15 FIGURE 6: POWERED ON/DOWN MODULE USING TRANSISTOR....................................................................... 16 FIGURE 7: POWERED ON/DOWN MODULE USING BUTTON ............................................................................... 16 FIGURE 8: TIMING OF POWER ON MODULE........................................................................................................... 16 FIGURE 9: TIMING OF POWER DOWN SIM900B BY PWRKEY ............................................................................. 17 FIGURE 10: TIMING OF RESTART SIM900B.............................................................................................................. 18 FIGURE 11: RTC SUPPLY FROM CAPACITOR........................................................................................................... 20 FIGURE 12: RTC SUPPLY FROM NON-CHARGEABLE BATTERY ......................................................................... 21 FIGURE 13: RTC SUPPLY FROM RECHARGEABLE BATTERY .............................................................................. 21 FIGURE 14: SEIKO XH414H-IV01E CHARGE-DISCHARGE CHARACTERISTIC ................................................. 21 FIGURE 15: CONNECTION OF THE SERIAL INTERFACES..................................................................................... 22 FIGURE 16: CONNECTION OF RXD AND TXD ONLY ............................................................................................. 22 FIGURE 17: CONNECTION FOR SOFTWARE UPGRADING AND DEBUGGING.................................................. 23 FIGURE 18: SPEAKER REFERENCE CIRCUIT .......................................................................................................... 24 FIGURE 19: SPEAKER WITH AMPLIFIER REFERENCE CIRCUIT ......................................................................... 24 FIGURE 20: MICROPHONE REFERENCE CIRCUIT.................................................................................................. 25 FIGURE 21: EARPHONE REFERENCE CIRCUIT ....................................................................................................... 25 FIGURE 22: REFERENCE CIRCUIT OF THE 8-PIN SIM CARD HOLDER............................................................... 27 FIGURE 23: REFERENCE CIRCUIT OF THE 6-PIN SIM CARD HOLDER............................................................... 27 FIGURE 24: AMPHENOL C707 10M006 5122 SIM CARD HOLDER......................................................................... 28 FIGURE 25: MOLEX 91228 SIM CARD HOLDER ...................................................................................................... 29 FIGURE 26: RI BEHAVIOUR OF VOICE CALLING AS A RECEIVER...................................................................... 30 FIGURE 27: RI BEHAVIOUR OF DATA CALLING AS A RECEIVER........................................................................ 31 FIGURE 28: RI BEHAVIOUR OF URC OR RECEIVE SMS ........................................................................................ 31 FIGURE 29: RI BEHAVIOUR AS A CALLER ............................................................................................................... 31 FIGURE 30: REFERENCE CIRCUIT OF NETLIGHT .................................................................................................. 32 FIGURE 31: REFERENCE CIRCUIT OF THE KEYPAD INTERFACE ....................................................................... 33 FIGURE 32: TOP AN SIDE MECHANICAL DIMENSIONS OF MODULE (UNIT: MM) .................................... 40 FIGURE 33: RECOMMENDED PCB FOOTPRINT OUTLINE(UNIT: MM).......................................................... 41 FIGURE 34: BB530-06001-20R BOARD-TO-BOARD CONNECTOR ........................................................................ 42 FIGURE 35 : BOARD-TO-BOARD CONNECTOR PHYSICAL PHOTO .................................................................... 42 FIGURE 36: U.FL-R-SMT............................................................................................................................................... 43 FIGURE 37: U.FL SERIES RF ADAPTER CABLE ....................................................................................................... 44 FIGURE 38: TOP VIEW OF THE SIM900B................................................................................................................... 44 SIM900B_Hardware Design_V2.00 6 2011-04-11 Version History Smart Machine Smart Decision Date 2010-04-08 2010-05-31 Version 1.01 1.02 2010-06-23 1.03 2010-08-19 1.04 2011-02-09 2.00 Description of change Author Origin Modify voltage domain , current consumption and figure37 Huangqiuju Huangqiuju §2.1, §3.3. §3.4 Modify the power supply range from 3.2V~4.8V to 3.1V~4.8V §3.7, Modify the VRTC pin connection when RTC backup is not needed. Huangqiuju Modify the power supply range to 3.2v~4.8v. §3.3.2 Add Figure 6:The minimal VBAT voltage at VBAT drop. §3.4 Modify figure 7. §3.4 Add table 7. §3.5 Add 3.5.4 and 3.5.5 description. Delete chapter 3.6. Add figure 29,figure 30,figure 31,figure 32 Modified figure 39 and B2B connector’s manufacture Huangqiuju Arrange the structure of document. Huangqiuju SIM900_Hardware Design_V2.00 7 2010.12.15 1 Introduction Smart Machine Smart Decision This document describes SIM900B hardware interface in great detail. This document can help user to quickly understand SIM900B interface specifications, electrical and mechanical details. With the help of this document and other SIM900B application notes, user guide, users can use SIM900B to design various applications quickly. 2 SIM900B Overview Designed for global market, SIM900B is a quad-band GSM/GPRS module that works on frequencies GSM 850MHz, EGSM 900MHz, DCS 1800MHz and PCS 1900MHz. SIM900B features GPRS multi-slot class 10/ class 8 (optional) and supports the GPRS coding schemes CS-1, CS-2, CS-3 and CS-4. With a tiny configuration of 40mm*33mm *3mm, SIM900B can meet almost all the space requirements in user applications, such as M2M, smart phone, PDA, FWP, and other mobile devices. The physical interface to the mobile application is a 60-pin board-to-board connector, which provides all hardware interfaces between the module and customers’ boards except the RF antenna interface. z Serial port and Debug port can help user easily develop the applications. z Two audio channels include two microphone inputs and two speaker outputs. z Programmable general purpose input and output. z The keypad and SPI display interface will give user the flexibility to develop customized applications. SIM900B 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 SIM900B Key Features Table 1: SIM900B key features Feature Power supply Power saving Frequency bands Transmitting power GPRS connectivity Temperature range Implementation 3.2V ~ 4.8V Typical power consumption in sleep mode is 1.0mA ( BS-PA-MFRMS=9 ) z SIM900B Quad-band: GSM 850, EGSM 900, DCS 1800, PCS 1900. SIM900B can search the 4 frequency bands automatically. The frequency bands also can be set by AT command “AT+CBAND”. For details, please refer to document [1]. z Compliant to GSM Phase 2/2+ z Class 4 (2W) at GSM 850 and EGSM 900 z Class 1 (1W) at DCS 1800 and PCS 1900 z GPRS multi-slot class 10(default) z GPRS multi-slot class 8 (option) z Normal operation: -30°C ~ +80°C SIM900B_Hardware Design_V2.00 8 2011-04-11 Smart Machine Smart Decision Data GPRS CSD USSD SMS z Restricted operation: -40°C ~ -30°C and +80 °C ~ +85°C* z Storage temperature -45°C ~ +90°C z GPRS data downlink transfer: max. 85.6 kbps z GPRS data uplink transfer: max. 42.8 kbps z Coding scheme: CS-1, CS-2, CS-3 and CS-4 z Integrate the TCP/IP protocol. z Support Packet Broadcast Control Channel (PBCCH) z Support CSD transmission z Unstructured Supplementary Services Data (USSD) support z MT, MO, CB, Text and PDU mode z SMS storage: SIM card FAX Group 3 Class 1 SIM interface Support SIM card: 1.8V, 3V External antenna Antenna pad Audio features Speech codec modes: z Half Rate (ETS 06.20) z Full Rate (ETS 06.10) z Enhanced Full Rate (ETS 06.50 / 06.60 / 06.80) z Adaptive multi rate (AMR) z Echo Cancellation z Noise Suppression Serial port and debug port Serial port: z Full modem interface with status and control lines, unbalanced, asynchronous. z 1200bps to 115200bps. z Can be used for AT commands or data stream. z Support RTS/CTS hardware handshake and software ON/OFF flow control. z Multiplex ability according to GSM 07.10 Multiplexer Protocol. z Autobauding supports baud rate from 1200 bps to 57600bps. Debug port: z Null modem interface DBG_TXD and DBG_RXD. z Can be used for debugging and upgrading firmware. Phonebook management Support phonebook types: SM, FD, LD, RC, ON, MC. SIM application toolkit GSM 11.14 Release 99 Real time clock Support RTC Physical characteristics Size: 40mm * 33mm*3mm Weight: 7g Firmware upgrade Firmware upgradeable by debug port. *SIM900B does work at this temperature, but some radio frequency characteristics may deviate from the GSM specification. SIM900B_Hardware Design_V2.00 9 2011-04-11 Table 2: Coding schemes and maximum net data rates over air interface Smart Machine Smart Decision Coding scheme CS-1 CS-2 CS-3 CS-4 1 timeslot 9.05kbps 13.4kbps 15.6kbps 21.4kbps 2 timeslot 18.1kbps 26.8kbps 31.2kbps 42.8kbps 4 timeslot 36.2kbps 53.6kbps 62.4kbps 85.6kbps 2.2 Operating Modes The table below summarizes the various operating modes of SIM900B. Table 3: Overview of operating modes Mode Normal operation Power down Minimum functionality mode Function GSM/GPRS SLEEP 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. GSM IDLE Software is active. Module registered to the GSM network, and the module is ready to communicate. GSM TALK Connection between two subscribers is in progress. In this case, the power consumption depends on network settings such as DTX off/on, FR/EFR/HR, hopping sequences, antenna. GPRS STANDBY Module is ready for GPRS data transfer, but no data is currently sent or received. In this case, power consumption depends on network settings and GPRS configuration. GPRS DATA There is GPRS data transfer (PPP or TCP or UDP) in progress. In this case, 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 the 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. SIM900B_Hardware Design_V2.00 10 2011-04-11 2.3 SIM900B Functional Diagram The following figure shows a functional diagram of SIM900B: z The GSM baseband engine z Flash and SRAM z The GSM radio frequency part z The antenna interface z The board-to-board interface z The Other interfaces A ntenna connector S IM 900B Radio Frequency Smart Machine Smart Decision Board-to-board Connector Flash+ SRAM POWER SIM KEYPADS Baseband Engine LCD UART GPIO ADC AUDIO Figure 1: SIM900B functional diagram SIM900B_Hardware Design_V2.00 11 2011-04-11 3 Application Interface Smart Machine Smart Decision 3.1 Pin Description Table 4: Pin description Pin name Power supply VBAT Pin number I/O Description 1,2,3,4,5,6,7,8 I Power supply VRTC 15 I/O Power supply for RTC Comment It is recommended to connect with a battery or a capacitor (e.g. 4.7uF). VDD_EXT 17 O 2.8V output power supply If it is unused, keep open. AGND 50,51 Analog ground Separate ground connection for external audio circuits. If unused connect to GND directory. GND 9,10,11,12,13, 14 Ground Power on/down PWRKEY 34 VILmax=0.9V VIHmin=2.6V PWRKEY should be pulled low at least VImax=3.3V I 1 second and then released to power VILmin= 0V on/down the module. It has been pulled up internally (3V). Audio interfaces MIC1P 53 MIC1N 55 I Differential audio input SPK1P 54 SPK1N 56 MIC2P 57 MIC2N 59 O Differential audio output I Differential audio input If these pins are unused, keep open. SPK2P 58 SPK2N 60 O Differential audio output Status NETLIGHT 30 O Network status LCD interface DISP _CLK 20 DISP_DATA 18 O Display interface I/O If these pins are unused, keep open. DISP _D/C 24 O SIM900B_Hardware Design_V2.00 12 2011-04-11 DISP _CS 22 DISP_RST 26 Keypad interface / GPIOs GPIO1/KBC4 35 GPIO2/KBC3 33 GPIO3/KBC2 31 GPIO4/KBC1 29 GPIO6/KBR3 45 GPIO7/KBR4 43 GPIO8/KBR2 41 GPIO9/KBR1 39 GPIO5/KBC0 27 GPIO10/KBR0 37 Serial port RXD 40 TXD 42 RTS 44 CTS 46 RI 48 DCD 28 DTR 38 Debug interface DBG_TXD 49 DBG_RXD 47 SIM interface SIM_VDD 19 SIM_DATA 21 SIM_CLK 23 SIM_RST 25 SIM_PRESEN 16 CE ADC ADC0 52 Pulse Width Modulation BUZZER 36 Smart Machine Smart Decision O O I/O I/O I/O Defaults are as GPIO, they can be I/O multiplexed as keypad I/O If these pins are unused ,keep open I/O I/O I/O I/O GPIO Just can be used as GPIO, if these pins are unused, keep open I Receive data O Transmit data I Request to send O Clear to send O Ring indicator O Data carry detect I Data terminal Ready This pin should be pulled up to 3V externally. If these pins are unused, keep open. O Serial interface for debugging and If these pins are unused, I firmware upgrade keep open. O Voltage supply for SIM card. Support 1.8V or 3V SIM card All signals of SIM I/O SIM data input/output O SIM clock interface should be protected against ESD with a TVS diode array. O SIM reset If SIM_PRESENCE is I SIM card detection unused, just keep open I General purpose analog to digital If it is unused ,keep open converter. Input voltage range: 0V ~ 2.8V O PWM Output If it is unused, keep open SIM900B_Hardware Design_V2.00 13 2011-04-11 3.2 Power Supply Smart Machine Smart Decision The power supply range of SIM900B 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 SIM900B VBAT pins. The following figure is the reference design of +5V input power supply. The designed output for the power supply is 4.1V, thus a linear regulator can be used. GND Figure 2: 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. Figure 3: Reference circuit of the DC-DC power supply The single 3.6V Li-ion cell battery can be connected to SIM900B 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 150mΩ. The following figure shows the VBAT voltage drop at the maximum power transmit phase, and the test condition is as following: VBAT=4.0V, A VBAT bypass capacitor CA=100µF tantalum capacitor (ESR=0.7Ω), Another VBAT bypass capacitor CB=1µF. SIM900_Hardware Design_V2.00 7 2010.12.15 Smart Machine Smart Decision Figure 4: VBAT voltage drop during transmit burst 3.2.1 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. 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. Figure 5: The minimal VBAT voltage requirement at VBAT drop 3.2.2 Monitoring Power Supply The AT command “AT+CBC” can be used to monitor the VBAT voltage. For detail, please refer to document [1]. 3.3 Power on/down Scenarios 3.3.1 Power on SIM900B 3.3.1.1 Turn on SIM900B Using the PWRKEY Pin (Power on) User can power on SIM900B 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. SIM900B_Hardware Design_V2.00 15 2011-04-11 Smart Machine Smart Decision Figure 6: Powered on/down module using transistor Figure 7: Powered on/down module using button The power on scenarios is illustrated as following figure. VBAT PWRKEY (INPUT) VDD_EXT Serial Port Pulldown >1s Delay > 2.2s VIL<0.9V 13m s VIH > 2.55V Undefined Active Figure 8: Timing of power on module When power on procedure is completed, SIM900B 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. After the configuration is saved as fixed baud rate, the Code “RDY” should be received from the serial port every time when SIM900B is powered on. For details, please refer to the chapter “AT+IPR” in document [1]. 3.3.2 Power down SIM900B SIM900B will be powered down in the following situations: z Normal power down procedure: power down SIM900B by the PWRKEY pin. z Normal power down procedure: power down SIM900B by AT command “AT+CPOWD=1”. z Abnormal power down: over-voltage or under-voltage automatic power down. z Abnormal power down: over-temperature or under-temperature automatic power down. SIM900B_Hardware Design_V2.00 16 2011-04-11 3.3.2.1 Power down SIM900B by the PWRKEY Pin Smart Machine Smart Decision User can power down SIM900B 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 the following figure. PWRKEY (INPUT) VDD_EXT (OUTPUT) 5s >Pulldown >1s Delay > 1.7s VIL<0.9V Logout net VIH > 2.55V VOL < 0.1V Figure 9: Timing of power down SIM900B 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. 3.3.2.2 Power down of SIM900B by AT Command SIM900B 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 “AT+CPOWD”, please refer to document [1] 3.3.2.3 Over-voltage or Under-voltage Power down The module software monitors the VBAT voltage constantly. If the voltage ≤ 3.3V, the following URC will be reported: UNDER-VOLTAGE WARNNING If the voltage ≥ 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. SIM900B_Hardware Design_V2.00 17 2011-04-11 Smart Machine Smart Decision UNDER-VOLTAGE POWER DOWN If the voltage > 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. 3.3.2.4 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. +CMTE: 2 If the temperature < -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 is still active. Power down mode can also be indicated by STATUS pin, which is at low level at this time. The AT command “AT+CMTE” could be used to read the temperature when the module is running. For details please refer to document [1]. 3.3.3 Restart SIM900B 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) Wait for at least 800mS after STATUS pin changed to low level. 3) Power on the module. PWRKEY (INPUT) Turn off VDD_EXT (OUTPUT) Delay > 800ms H Restart Pull down the PWRKEY to turn on the module Figure 10: Timing of restart SIM900B SIM900B_Hardware Design_V2.00 18 2011-04-11 3.4 Power Saving Mode Smart Machine Smart Decision SIM900B has two sleep modes: sleep mode 1 is enabled by hardware pin DTR; sleep mode 2 is only enabled by serial port regardless of the DTR. In sleep mode, the current consumption of the module is very low. The AT command “AT+CFUN=” can be used to set SIM900B into minimum functionality. When SIM900B is in sleep mode and minimum functionality, the current of module is the lowest. 3.4.1 Minimum Functionality Mode There are three functionality modes, which could be set by the AT command “AT+CFUN=”. The command provides the choice of the functionality levels =0,1,4. 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 SIM900B 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 the AT Command “AT+CFUN=”, please refer to document [1]. Table 5:The Current consumption of Minimum Functionality Mode 0 1 4 Current consumption(uA) (sleep mode) 651 1000 715 3.4.2 Sleep Mode 1 (AT+CSCLK=1) User can control SIM900B 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), SIM900B will enter sleep mode 1 automatically. In this mode, SIM900B can still receive paging or SMS from network but the serial port is not accessible. Note: For SIM900B, it is requested to set AT command “AT+CSCLK=1” and to ensure DTR at high level to enable the sleep mode 1; the default value is 0, which can not make the module to go into sleep mode. For more details please refer to document [1]. 3.4.3 Wake Up SIM900B from Sleep Mode 1 (AT+CSCLK=1) When SIM900B is in sleep mode 1 (AT+CSCLK=1), the following methods can wake up the module: z Pull down DTR pin. The serial port will be active after DTR pin is pulled to low level for about 50ms. SIM900B_Hardware Design_V2.00 19 2011-04-11 z Receive a voice or data call from network. z Receive a SMS from network. Smart Machine Smart Decision 3.4.4 Sleep Mode 2 (AT+CSCLK=2) In this mode, SIM900B will continuously monitor the serial port data signal. When there is no data transfer over 5 seconds on the RXD signal and there is no on air and hardware interrupts (such as GPIO interrupt), SIM900B will enter sleep mode 2 automatically. In this mode, SIM900B can still receive paging or SMS from network but the serial port is not accessible. Note: For SIM900B, 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]. 3.4.5 Wake Up SIM900B from Sleep Mode 2 (AT+CSCLK=2) When SIM900B is in sleep mode 2 (AT+CSCLK=2), the following methods can wake up the module: z Send data to SIM900B 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. 3.5 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 the 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. z External capacitor backup Figure 11: RTC supply from capacitor z Non-chargeable battery backup SIM900B_Hardware Design_V2.00 20 2011-04-11 Smart Machine Smart Decision Figure 12: RTC supply from non-chargeable battery z Rechargeable battery backup Figure 13: RTC supply from rechargeable battery 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 14: Seiko XH414H-IV01E Charge-Discharge Characteristic 3.6 Serial Interfaces SIM900B 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 between module and client (DTE). SIM900B_Hardware Design_V2.00 21 2011-04-11 MODULE (DCE) Serial port TXD RXD RTS CTS DTR DCD RI Debug port DBG_TX DBG_RX Smart Machine Smart Decision CUSTOMER (DTE) Serial port1 TXD RXD RTS CTS DTR DCD RING Serial port2 TXD RXD Figure 15: Connection of the serial interfaces 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) Serial port TXD RXD RTS CTS DTR DCD RI Debug port DBG_TX DBG_RX CUSTOMER (DTE) Serial port1 TXD RXD RTS CTS DTR DCD RING Serial port2 TXD RXD Figure 16: Connection of RXD and TXD only Note: if sleep mode is need in this situation, the user nees to connect the DTR signal as well, or only sleep mode2 can be used. For details, please refer to document [7]. 3.6.1 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. It can also be used for multiplexing function. For details about multiplexing function, please refer to document [7]. z Serial port supports the following baud rates: 1200, 2400, 4800, 9600, 19200, 38400, 57600 and 115200bps z Autobauding only supports the following baud rates: 1200, 2400, 4800, 9600, 19200, 38400 and 57600bps z The default setting is autobauding. SIM900B_Hardware Design_V2.00 22 2011-04-11 Smart Machine Smart Decision Autobauding allows SIM900B to automatically detect the baud rate of the host device. Pay more attention to the following requirements: z 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 DTE receives the “OK” response, which means DTE and DCE are correctly synchronized. For more information please refer to the AT command “AT+IPR”. z 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", "+CFUN: 1" and "+CPIN: READY” will be reported when SIM900B is powered on. Debug port: z Used for debugging and upgrading firmware. z Debug port supports the baud rate of 115200bps. 3.6.2 Software Upgrade and Debug Refer to the following figure for debugging and upgrading software. MODULE DBG_TXD DBG_RXD VBAT PWRKEY GND VBAT C1 RS232 TXD_IN RXD_OUT TXD_OUT RXD_IN GND PC RXD TXD GND Figure 17: 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]. 3.7 Audio Interfaces SIM900B provides two analog inputs, MIC1P/1N 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 32Ω receiver. SIM900B_Hardware Design_V2.00 23 2011-04-11 Smart Machine Smart Decision 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. 3.7.1 Speaker Interface Configuration Figure 18: Speaker reference circuit Figure 19: Speaker with amplifier reference circuit SIM900B_Hardware Design_V2.00 24 2011-04-11 3.7.2 Microphone Interfaces Configuration Smart Machine Smart Decision Figure 20: Microphone reference circuit 3.7.3 Earphone Interface Configuration Figure 21: Earphone reference circuit 3.7.4 Audio Electronic Characteristics SIM900B_Hardware Design_V2.00 25 2011-04-11 Table 6: Microphone Input Characteristics Parameter Min Working Voltage 1.2 Working Current 200 External Microphone Load Resistance 1.2 Internal biasing DC Characteristics Differential input THD <1% at voltage F=1KHz; pre-amp gain = 20 dB; PGA gain = 14 dB THD <5% at F=1KHz;pre-amp gain = 0 dB; PGA gain = 0 dB Smart Machine Smart Decision Typ Max Unit 1.5 2.0 V 500 uA 2.2 kΩ 2.5 V 15.9 mVrms 740 mVrms Table 7: Audio Output Characteristics Parameter Normal Output(SPK) Conditions Min RL=32Ω - THD=0.1% RL=32Ω - THD=1% Output swing Voltage (single ended) Output swing Voltage (differential) 3.8 SIM Card Interface Typ Max Unit 91 - mW 96 - mW 1.1 Vpp 2.2 Vpp 3.8.1 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 cards 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.The pull-up resistor (15KΩ) 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. SIM900B_Hardware Design_V2.00 26 2011-04-11 Smart Machine Smart Decision Figure 22: Reference circuit of the 8-pin 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 is illustrated in the following figure. Figure 23: Reference circuit of the 6-pin SIM card holder 3.8.2 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. SIM900B_Hardware Design_V2.00 27 2011-04-11 Smart Machine Smart Decision Figure 24: Amphenol C707 10M006 5122 SIM card holder Table 8: Pin description (Amphenol SIM card holder) Pin name C1 C2 C3 C5 C6 C7 Signal SIM_VDD SIM_RST SIM_CLK GND VPP SIM_DATA Description SIM card power supply SIM card reset SIM card clock Connect to GND Not connect 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. SIM900B_Hardware Design_V2.00 28 2011-04-11 Smart Machine Smart Decision Figure 25: Molex 91228 SIM card holder Table 9: Pin description (Molex SIM card holder) Pin name C1 C2 C3 C4 C5 C6 C7 C8 Signal SIM_VDD SIM_RST SIM_CLK GND GND VPP SIM_DATA SIM_PRESENCE Description SIM card power supply SIM card reset SIM card clock Connect to GND Connect to GND Not connect SIM card data I/O Detect SIM card presence 3.9 LCD Display/SPI Interface SIM900B 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 [6]. 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. SIM900B_Hardware Design_V2.00 29 2011-04-11 3.10 ADC Smart Machine Smart Decision SIM900B 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 10: ADC specification Parameter Voltage range ADC Resolution Sampling rate Min Typ Max Unit 0 - 2.8 V - 10 - bits - - 200K Hz 3.11 RI Behaviors Table 11: RI Behaviors State Standby Voice call Data call SMS URC RI response High The pin is changed to low. When any of the following events occurs, the pin will be changed to high: (1)Establish the call (2)Hang up the call The pin is changed to low. When any of the following events occurs, the pin will be changed to high: (1)Establish the call (2)Hang up the call The pin is changed to low, and kept low for 120ms when a SMS is received. Then it is changed to high. The pin 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 [7]. The behavior of the RI pin is shown in the following figure when the module is used as a receiver. Figure 26: RI behaviour of voice calling as a receiver SIM900B_Hardware Design_V2.00 30 2011-04-11 RI HIGH Smart Machine Smart Decision LOW Idle Ring Establish the call Hang up the call Figure 27: RI behaviour of data calling as a receiver Figure 28: 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 29: RI behaviour as a caller 3.12 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: Table 12: Status of the NETLIGHT pin Status Off 64ms On/ 800ms Off 64ms On/ 3000ms Off 64ms On/ 300ms Off SIM900B behavior SIM900B is not running SIM900B not registered the network SIM900B registered to the network GPRS communication is established A reference circuit is recommended in the following figure: SIM900B_Hardware Design_V2.00 31 2011-04-11 Smart Machine Smart Decision Figure 30: Reference circuit of NETLIGHT 3.13 General Purpose Input/Output (GPIO) 3.14 Keypad Interface The keypad interface consists of 5 keypad column outputs and 4 keypad row inputs. The basic configuration is 5 keypad columns and 4 keypad rows, giving 20 keys. Table 13: Pin definition of the keypad interface Name GPIO5/KBC0 GPIO4/KBC1 GPIO3/KBC2 GPIO2/KBC3 GPIO1/KBC4 GPIO9/KBR1 GPIO8/KBR2 GPIO7/KBR3 GPIO6/KBR4 Pin Function 27 29 31 Keypad matrix column 33 35 39 41 Keypad matrix row 43 45 The keypad interface allows a direct external matrix connection. A typical recommended circuit of the keypad is as shown in the following figure. SIM900B_Hardware Design_V2.00 32 2011-04-11 GND KBC0 KBC1 KBC2 KBC3 KBC4 MODULE Smart Machine Smart Decision KBR1 KBR2 KBR3 KBR4 Figure 31: Reference circuit of the keypad interface *Note: 1. 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. 2. KBR0&KBC0 are used to power off the module, so user can’t connect these two pins as a key. 3. keypad is the second function of these pins, the default function is GPIO. 3.15 Buzzer Features of buzzer: z 10-bit resolution for buzzer tone frequency generation from 200 Hz to 5 kHz z Tone frequency error < 1 % for all standard piano notes from 200 Hz to 5 kHz z Tone level control from 0 dB down to −24 dB in +4 dB steps z 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. For details, please refer to document[1] SIM900B_Hardware Design_V2.00 33 2011-04-11 4 Electrical, Reliability and Radio Characteristics Smart Machine Smart Decision 4.1 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 SIM900B. Table 14: Absolute maximum ratings Symbol Parameter Min Typ Max VBAT Power supply voltage - - 5.5 VI* Input voltage -0.3 - 3.1 II* Input current - - 10 IO* Output current - - 10 *These parameters are for digital interface pins, such as GPIO, UART, LCD, PWM and DEBUG. Unit V V mA mA 4.2 Recommended Operating Conditions Table 15: Recommended operating conditions Symbol VBAT TOPER TSTG Parameter Power supply voltage Operating temperature Storage temperature Min Typ Max Unit 3.2 4.0 4.8 V -40 +25 +85 ℃ -45 +90 ℃ 4.3 Digital Interface Characteristics Table 16: Digital interface characteristics Symbol Parameter Min Typ Max IIH High-level input current -10 - 10 IIL Low-level input current -10 - 10 VIH High-level input voltage 2.4 - - VIL Low-level input voltage - - 0.4 VOH High-level output voltage 2.7 - - VOL Low-level output voltage - - 0.1 * These parameters are for digital interface pins, such as GPIO,, UART, LCD, PWM and DEBUG. Unit uA uA V V V V 4.4 SIM Card Interface Characteristics SIM900B_Hardware Design_V2.00 34 2011-04-11 Table 17: SIM card interface characteristics Smart Machine Smart Decision Symbol Parameter Min Typ Max Unit IIH High-level input current -10 - 10 uA IIL Low-level input current -10 - 10 uA 1.4 - - V VIH High-level input voltage 2.4 - - V - - 0.4 V VIL Low-level input voltage 2.4 V 1.7 - - V VOH High-level output voltage 2.7 - - V - - 0.1 V VOL Low-level output voltage - - 0.1 V 4.5 SIM_VDD Characteristics Table 18: SIM_VDD characteristics Symbol VO IO Parameter Output voltage Output current Min Typ Max Unit 2.75 2.9 3.00 V 1.65 1.80 1.95 - - 10 mA 4.6 VRTC Characteristics Table 19: VRTC characteristics Symbol VRTC-IN IRTC-IN VRTC-OUT IRTC-OUT Parameter VRTC input voltage VRTC input current VRTC output voltage VRTC output current Min Typ Max Unit 2.00 3.00 3.15 V - 2 - uA - 3.00 - V - 10 - uA 4.7 Current Consumption (VBAT = 3.8V) Table 20: Current consumption Symbol IVRTC IVBAT Parameter VRTC current VBAT current SIM900B_Hardware Design_V2.00 Conditions VBAT disconnects. Backup battery is 3 V Power down mode Sleep mode BS-PA-MFRMS=9 35 Value 2 30 1.0 Unit uA uA mA 2011-04-11 IVBAT-peak Peak current Idle mode Voice call Data mode GPRS(1Rx,1Tx) Data mode GPRS(4Rx,1Tx) Data mode GPRS(3Rx,2Tx) During Tx burst Smart Machine Smart Decision BS-PA-MFRMS=5 1.2 BS-PA-MFRMS=2 1.5 GSM 850 EGSM 900 DCS 1800 22 mA PCS 1900 GSM 850 EGSM 900 DCS 1800 PCS 1900 PCL=5 250 PCL=12 110 PCL=19 80 mA PCL=0 180 PCL=7 94 PCL=15 76 GSM 850 EGSM 900 PCL=5 235 PCL=12 102 mA PCL=19 74 DCS 1800 PCS 1900 PCL=0 170 PCL=7 90 mA PCL=15 70 GSM 850 EGSM 900 PCL=5 273 PCL=12 145 mA PCL=19 120 DCS 1800 PCS 1900 PCL=0 205 PCL=7 130 mA PCL=15 110 GSM 850 EGSM 900 PCL=5 440 PCL=12 185 mA PCL=19 125 DCS 1800 PCS 1900 PCL=0 320 PCL=7 155 mA PCL=15 120 2 A 4.8 Electro-Static Discharge SIM900B 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 21: The ESD characteristics (Temperature: 25℃, Humidity: 45 %) Pin VBAT GND SIM900B_Hardware Design_V2.00 Contact discharge ±5KV ±5KV 36 Air discharge ±10KV ±10KV 2011-04-11 RXD, TXD Antenna port SPK1P/ SPK1N SPK2P/ SPK2N MIC1P/ MIC1N MIC2P/ MIC2N PWRKEY ±2KV ±5KV ±2KV ±2KV Smart Machine Smart Decision ±8KV ±10KV ±5KV ±8KV 4.9 Radio Characteristics 4.9.1 Module RF Output Power The following table shows the module conducted output power, it is followed by the 3GPP TS 05.05 technical specification requirement. Table 22: SIM900B GSM 900 and GSM 850 conducted RF output power PCL 0-2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19-31 GSM 900 and EGSM 850 Nominal output power (dBm) Tolerance (dB) for conditions Normal Extreme 39 ±2 ±2.5 37 ±3 ±4 35 ±3 ±4 33 ±3 ±4 31 ±3 ±4 29 ±3 ±4 27 ±3 ±4 25 ±3 ±4 23 ±3 ±4 21 ±3 ±4 19 ±3 ±4 17 ±3 ±4 15 ±3 ±4 13 ±3 ±4 11 ±5 ±6 9 ±5 ±6 7 ±5 ±6 5 ±5 ±6 SIM900B_Hardware Design_V2.00 37 2011-04-11 Table 23: SIM900B DCS 1800 and PCS 1900 conducted RF output power Smart Machine Smart Decision PCL 29 30 31 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15-28 DCS 1800 and PCS 1900 Nominal output power (dBm) Tolerance (dB) for conditions Normal Extreme 36 ±2 ±2.5 34 ±3 ±4 32 ±3 ±4 30 ±3 ±4 28 ±3 ±4 26 ±3 ±4 24 ±3 ±4 22 ±3 ±4 20 ±3 ±4 18 ±3 ±4 16 ±3 ±4 14 ±3 ±4 12 ±4 ±5 10 ±4 ±5 8 ±4 ±5 6 ±4 ±5 4 ±4 ±5 2 ±5 ±6 0 ±5 ±6 For the module’s output power, the following should be noted: At GSM900 and GSM850 band, the module is a class 4 device, so the module’s output power should not exceed 33dBm, and at the maximum power level, the output power tolerance should not exceed +/-2dB under normal condition and +/-2.5dB under extreme condition. At DCS1800 and PCS1900 band, the module is a class 1 device, so the module’s output power should not exceed 30dBm, and at the maximum power level, the output power tolerance should not exceed +/-2dB under normal condition and +/-2.5dB under extreme condition. 4.9.2 Module RF Receive Sensitivity The following table shows the module’s conducted receive sensitivity, it is tested under static condition. SIM900B_Hardware Design_V2.00 38 2011-04-11 Table 24: SIM900B conducted RF receive sensitivity Frequency GSM850 EGSM900 DCS1800 PCS1900 Receive sensitivity(Typical) -109dBm -109dBm -109dBm -109dBm Smart Machine Smart Decision Receive sensitivity(Max) -107dBm -107dBm -107dBm -107dBm 4.9.3 Module Operating Frequencies The following table shows the module’s operating frequency range; it is followed by the 3GPP TS 05.05 technical specification requirement. Table 25: SIM900B operating frequencies Frequency GSM850 EGSM900 DCS1800 PCS1900 Receive 869 ~ 894MHz 925 ~ 960MHz 1805 ~ 1880MHz 1930 ~ 1990MHz Transmit 824 ~ 849 MHz 880 ~ 915MHz 1710 ~ 1785MHz 1850 ~ 1910MHz SIM900B_Hardware Design_V2.00 39 2011-04-11 5 Manufacturing Smart Machine Smart Decision This chapter describes the mechanical dimensions of SIM900B. 5.1 Mechanical Dimensions of SIM900B Following figure shows the Mechanical dimensions of SIM900B (top view, side view and bottom view). Figure 32: Top an Side Mechanical dimensions of module (Unit: mm) SIM900B_Hardware Design_V2.00 40 2011-04-11 Smart Machine Smart Decision Figure 33: Recommended PCB footprint outline(Unit: mm) 5.2 Mounting SIM900B onto the application platform Use the connector BB530-06001-20R to fix the SIM900B onto the customer platform. 5.3 Board-to-board connector SIMCom recommends to use RUNFENG Company’s BB530-06001-20R as the board-to-board connector. This high density SMT connector is designed for parallel PCB-to-PCB applications. It is ideal to use in VCRs, notebook PCs, cordless telephones, mobile phones, audio/visual and other telecommunications equipment where reduced size and weight are important. Following is the parameter of BB530-06001-20R. User can contact SIMCom for more information. SIM900B_Hardware Design_V2.00 41 2011-04-11 5.4 Mechanical dimensions of the RUNFENG BB530-06001-20R Smart Machine Smart Decision Figure 34: BB530-06001-20R board-to-board connector Figure 35 : Board-to-board connector physical photo SIM900B_Hardware Design_V2.00 42 2011-04-11 5.5 RF connector Smart Machine Smart Decision 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 are parameters (Figure 36). Certainly user can 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(V)-040), the following figure (Figure 41) is the dimensions of U.FL series RF adapter cable. User can contact SIMCom for more information. Figure 36: U.FL-R-SMT Unit:mm Unit:mm SIM900B_Hardware Design_V2.00 43 2011-04-11 Figure 37: U.FL series RF adapter cable 5.6 Top View of the SIM900B Smart Machine Smart Decision Figure 38: Top view of the SIM900B SIM900B_Hardware Design_V2.00 44 2011-04-11 5.7 PIN Assignment of SIM900B Table 26: PIN assignment PIN NO. PIN NAME I/O 1 VBAT I 3 VBAT I 5 VBAT I 7 VBAT I 9 GND 11 GND 13 GND 15 VRTC I/O 17 VDD_EXT O 19 SIM_VDD O 21 SIM_DATA I/O 23 SIM_CLK O 25 SIM_RST O 27 GPIO5/KBC0 I/O 29 GPIO4/KBC1 I/O 31 GPIO3/KBC2 I/O 33 GPIO2/KBC3 I/O 35 GPIO1/KBC4 I/O 37 GPIO10/KBR0 I/O 39 GPIO9/KBR1 I/O 41 GPIO8/KBR2 I/O 43 GPIO7/KBR3 I/O 45 GPIO6/KBR4 I/O 47 DBG_RXD I 49 DBG_TXD O 51 AGND 53 MIC1P I 55 MIC1N I 57 MIC2P I 59 MIC2N I Smart Machine Smart Decision PIN NO. 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 PIN NAME I/O VBAT I VBAT I VBAT I VBAT I GND GND GND SIM_PRESENCE I DISP_DATA I/O DISP_CLK O DISP_CS O DISP_D/C O DISP_RST O DCD O NETLIGHT O GPIO0 I/O PWRKEY I BUZZER O DTR I RXD I TXD O RTS I CTS O RI O AGND ADC0 I SPK1P O SPK1N O SPK2P O SPK2N O SIM900B_Hardware Design_V2.00 45 2011-04-11 Smart Machine Smart Decision Appendix A. Related Documents Table 27: Related documents SN Document name Remark [1] SIM900_AT Command SIM900 AT Command Manual Manual [2] AN_SIM900_TCPIP TCP/IP Applications User Manual [3] SIM900_Multiplexer User SIM900 Multiplexer User Manual Application Note Manual_Application Note [4] AN_SIM900 SIM900 Series Update Tool User Guide Series_Update Tool_UGD [5] AN_SIM900_AUDIO Applications Note About SIM900 Audio [6] SIM900_Embedded AT SIM900 Embedded AT Application Note Application Note [7] AN_Serial Port Application Note About Serial Port [8] AN_SIM900-TE PCB Application Note About SIM900-TE PCB Layout & Schematic Layout & Schematic for Reference [9] Module secondary-SMT-UGD Module secondary SMT User Guide [10] ITU-T Draft new Serial asynchronous automatic dialing and control recommendation V.25ter: [11] GSM 07.07: Digital cellular telecommunications (Phase 2+); AT command set for GSM Mobile Equipment (ME) [12] GSM 07.10: Support GSM 07.10 multiplexing protocol [13] GSM 07.05: Digital cellular telecommunications (Phase 2+); Use of Data Terminal Equipment – Data Circuit terminating Equipment (DTE – DCE) interface for Short Message Service (SMS) and Cell Broadcast Service (CBS) [14] GSM 11.14: Digital cellular telecommunications system (Phase 2+); Specification of the SIM Application Toolkit for the Subscriber Identity Module – Mobile Equipment (SIM – ME) interface [15] GSM 11.11: Digital cellular telecommunications system (Phase 2+); Specification of the Subscriber Identity Module – Mobile Equipment (SIM – ME) interface [16] GSM 03.38: [17] GSM 11.10 Digital cellular telecommunications system (Phase 2+); Alphabets and language-specific information Digital cellular telecommunications system (Phase 2); Mobile Station (MS) conformance specification; Part 1: Conformance specification SIM900B_Hardware Design_V2.00 46 2011-04-11 B. Terms and Abbreviations Smart Machine Smart Decision Table 28: Terms and Abbreviations Abbreviation ADC AMR CS CSD CTS DTE DTR DTX EFR EGSM ESD ETS FR GPRS GSM HR IMEI Li-ion MO MS MT PAP PBCCH PCB PCL PCS PDU PPP RF RMS RTC RX SIM SMS TE TX UART Description Analog-to-Digital Converter Adaptive Multi-Rate Coding Scheme Circuit Switched Data Clear to Send Data Terminal Equipment (typically computer, terminal, printer) Data Terminal Ready Discontinuous Transmission Enhanced Full Rate Enhanced GSM Electrostatic Discharge European Telecommunication Standard Full Rate General Packet Radio Service Global Standard for Mobile Communications Half Rate International Mobile Equipment Identity Lithium-Ion Mobile Originated Mobile Station (GSM engine), also referred to as TE Mobile Terminated Password Authentication Protocol Packet Broadcast Control Channel Printed Circuit Board Power Control Level Personal Communication System, also referred to as GSM 1900 Protocol Data Unit Point-to-point protocol Radio Frequency Root Mean Square (value) Real Time Clock Receive Direction Subscriber Identification Module Short Message Service Terminal Equipment, also referred to as DTE Transmit Direction Universal Asynchronous Receiver & Transmitter SIM900B_Hardware Design_V2.00 47 2011-04-11 URC USSD Phonebook abbreviations FD LD MC ON RC SM NC Unsolicited Result Code Unstructured Supplementary Service Data Smart Machine Smart Decision 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 29: Safety caution Marks Requirements When in a hospital or other health care facility, observe the restrictions about the use of mobiles. Switch the cellular terminal or mobile off, medical equipment may be sensitive to not operate normally for RF energy interference. Switch off the cellular terminal or mobile before boarding an aircraft. Make sure it is switched off. The operation of wireless appliances in an aircraft is forbidden to prevent interference with communication systems. Forget to think much of these instructions may lead to the flight safety or offend against local legal action, or both. Do not operate the cellular terminal or mobile in the presence of flammable gases or fumes. Switch off the cellular terminal when you are near petrol stations, fuel depots, chemical plants or where blasting operations are in progress. Operation of any electrical equipment in potentially explosive atmospheres can constitute a safety hazard. Your cellular terminal or mobile receives and transmits radio frequency energy while switched on. RF interference can occur if it is used close to TV sets, radios, computers or other electric equipment. Road safety comes first! Do not use a hand-held cellular terminal or mobile when driving a vehicle, unless it is securely mounted in a holder for hands free operation. Before making a call with a hand-held terminal or mobile, park the vehicle. GSM cellular terminals or mobiles operate over radio frequency signals and cellular networks and cannot be guaranteed to connect in all conditions, for example no mobile fee or a invalid SIM card. While you are in this condition and need emergent help, please remember using emergency calls. In order to make or receive calls, the cellular terminal or mobile must be switched on and in a service area with adequate cellular signal strength. Some networks do not allow for emergency call if certain network services or phone features are in use (e.g. lock functions, fixed dialing etc.). You may have to deactivate those features before you can make an emergency call. Also, some networks require that a valid SIM card be properly inserted in the cellular terminal or mobile. SIM900B_Hardware Design_V2.00 48 2011-04-11 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 SIM900B_Hardware Design_V2.00 49 2011-04-11

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