SIM968_Hardware Design_V1.
Smart Machine Smart Decision Document Title SIM968 Hardware Design Version 1.00 Date 2013-02-25 Status Release Document Control ID SIM968_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 4.8.2 4.9 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 Design Considerations for SIM Card Holder ...................................................................................... 34 LCD Display/SPI Interface..................................................................................................................... 36 Keypad Interface ...................................................................................................................................
Smart Machine Smart Decision C. Safety Caution ................................................................................................................................................. 58 Table Index TABLE 1: SIM968 GSM/GPRS ENGINE KEY FEATURES ........................................................................................... 9 TABLE 2: GNSS ENGINE PERFORMANCE ................................................................................................................
Smart Machine Smart Decision Figure Index FIGURE 1: SIM968 FUNCTIONAL DIAGRAM ........................................................................................................... 12 FIGURE 2: SIM968 PIN OUT DIAGRAM (TOP VIEW) ............................................................................................... 13 FIGURE 3: DIMENSIONS OF SIM968（UNIT: MM）................................................................................................
Smart Machine Smart Decision Version History Date Version Description of change Author 2013-02-25 1.00 Origin Shengwu.sun， Xiaohan.jin SIM968_Hardware Design_V1.00 7 2013.02.
Smart Machine Smart Decision 1 Introduction This document describes SIM968 hardware interface in great detail. This document can help user to quickly understand SIM968 interface specifications, electrical and mechanical details. With the help of this document and other SIM968 application notes, user guide, users can use SIM968 to design various applications quickly. 2 SIM968 Overview Designed for global market, SIM968 is integrated with a high performance GSM/GPRS engine and a GNSS engine.
Smart Machine Smart Decision 2.1 SIM968 Key Features Table 1: SIM968 GSM/GPRS engine key features Feature Implementation Power supply 3.2V ~ 4.8V Power saving Typical power consumption in sleep mode is 1.2mA ( BS-PA-MFRMS=9, GNSS engine is powered down ) Charging Supports charging control for Li-Ion battery z z SIM968 Quad-band: GSM 850, EGSM 900, DCS 1800, PCS 1900. SIM968 can search the 4 frequency bands automatically. The frequency bands also can be set by AT command “AT+CBAND”.
Smart Machine Smart Decision z z z z z z z * 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 and DBG_RXD. Can be used for debugging and upgrading firmware. Phonebook management Support phonebook types: SM, FD, LD, RC, ON, MC.
Smart Machine Smart Decision Code Protocol support NMEA,PMTK Power consumption(4) Acquisition 34 mA Continuous tracking 37 mA Sleep current 440 uA Backup current 14 uA (1) 50% 24hr static, -130dBm (2) 50% at 30m/s (3) –130 dBm, GPS&GLONASS mode (4) Single Power supply 3.3V under GPS+GLONASS signal Table 3: 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.
Smart Machine Smart Decision Power down 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.
Smart Machine Smart Decision 3 3.1 Package Information Pin out Diagram Figure 2: SIM968 pin out diagram (Top view) 3.2 Pin Description Table 5: Pin description SIM968_Hardware Design_V1.00 13 2013.02.
Smart Machine Smart Decision Pin name Pin number I/O Description Comment 62, 63 I GSM power supply 3.2V ~ 4.8V Power supply VBAT VRTC 42 I/O Power supply for GSM RTC It is recommended to connect with a battery or a capacitor (e.g. 4.7uF). VDD_EXT 44 O 2.8V output power supply If it is unused, keep open. GPS_VCC 12 I GNSS Power supply 2.8V~4.3V V_BACKUP 13 I Power supply for GNSS RTC It is recommended to connect with a battery or LDO GPS_VANT_OUT 75 O 2.
Smart Machine Smart Decision DISP _D/C 8 O DISP _CS 9 O 56 O I2C interface I2C_SDA I2C_SCL 55 I/O I2C serial bus data If these pins are unused, keep open.
Smart Machine Smart Decision controlled to 50Ω. GPS_ANT 79 I GNSS radio antenna connection Impendence must controlled to 50Ω. be RF_SYNS 53 O RF synchronization If unused, keep open RESET 4 I GSM Reset input, active low If unused, keep open. AADET_N 46 I GNSS Active Antenna Detect If unused, keep open. GPS_WAKEUP 54 I GNSS engine wake up from Backup mode, active High. If unused, keep open. NC 45 Not Connected This pin should be kept open. Other interface 3.
Smart Machine Smart Decision Figure 4: Recommended PCB footprint outline（Unit: mm） SIM968_Hardware Design_V1.00 17 2013.02.
Smart Machine Smart Decision 4 4.1 GSM Application Interface GSM Power Supply GND The GSM power supply range of SIM968 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 SIM968 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, SIM968 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 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 SIM968 SIM968 will be powered down in the following situations： z Normal power down procedure: power down SIM968 by the PWRKEY pin. z Normal power down procedure: power down SIM968 by AT command “AT+CPOWD=1”. z Abnormal power down: over-voltage or under-voltage automatic power down.
Smart Machine Smart Decision 4.2.2.3 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. UNDER-VOLTAGE POWER DOWN If the voltage > 4.
Smart Machine Smart Decision 4.3 Power Saving Mode SIM968 have 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 of module is very low. The AT command “AT+CFUN=” can be used to set SIM968 into minimum functionality. When SIM968 is in sleep mode and minimum functionality, the current of module is lowest. 4.3.
Smart Machine Smart Decision z z Receive a voice or data call from network. Receive a SMS from network. 4.3.4 Sleep Mode 2 (AT+CSCLK=2) AT+CSCLK=2 can set module to the sleep mode 2. In this mode, SIM968 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), SIM968 will enter sleep mode 2 automatically.
Smart Machine Smart Decision 4.4.1 Battery Pack Characteristics SIM968 has optimized the charging algorithm for the Li-Ion battery that meets the characteristics listed below. z The maximum charging voltage of the Li-Ion battery pack is 4.2V and the recommended capacity is 1100mAh. The Battery packs with more than 1100 mAh capacity will take more time for charging.
Smart Machine Smart Decision supply or no battery present, charging function will not be enabled. Normally, there are three main states in the whole charging procedure. z DDLO charge (Pull-up mode) and UVLO charge (Pre-charge mode); z Fast charge; DDLO charge and UVLO charge: DDLO is the state of battery when its voltage is under 1.5V. And UVLO means the battery voltage is less than 3.3V and more than 1.5V. The battery is not suitable for fast charging when its condition is DDLO or UVLO.
Charge-only Mode Smart Machine Smart Decision Connect charger to module’s VCHG Pin while SIM968 is in POWER DOWN mode. IMPORTANT: Here Charge-only mode is charging when power is down, it means that not all software tasks are running. z Battery can be charged when GSM engine is not registered to GSM network; z Only a few AT commands is available, as listed below. Note: VBAT can not provide more than 5mA current while SIM968 module is during the DDLO charge state.
Smart Machine Smart Decision Figure 15: RTC supply from capacitor z Non-chargeable battery for RTC Figure 16: RTC supply from non-chargeable battery z Rechargeable battery for RTC Figure 17: RTC supply from rechargeable battery Coin-type rechargeable battery is recommended, such as XH414H-IV01E from Seiko can be used. Typical charge-discharge curves for this battery are shown in the following figure. Figure 18: Seiko XH414H-IV01E charge-discharge characteristic SIM968_Hardware Design_V1.
Smart Machine Smart Decision 4.6 Serial Interfaces SIM968 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). Figure 19: 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.
Smart Machine Smart Decision z 1200, 2400, 4800, 9600, 19200, 38400 and 57600bps The default setting is autobauding. Autobauding allows SIM968 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.
Smart Machine Smart Decision 4.7 Audio Interfaces SIM968 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. 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.
Smart Machine Smart Decision 4.7.2 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 MIC1P MODULE MIC1N 10pF ESD ANTI 33pF Figure 24 : Microphone reference circuit Microphone input also could be used to LINE-IN input. For details, please refer to document [6]. 4.7.
Smart Machine Smart Decision Differential input voltage THD <1% at F=1KHz; pre-amp gain = 20 dB; PGA gain = 14 dB 15.9 mVrms THD <5% at F=1KHz; pre-amp gain = 0 dB; PGA gain = 0 dB 740 mVrms Table 11: Audio output characteristics Parameter Normal Output(SPK) 4.8 Conditions Min Typ Max Unit RL=32Ω THD=0.1% - 91 - mW RL=32Ω THD=1% - 96 - mW Output swing voltage (single ended) 1.1 Vpp Output swing voltage (differential) 2.2 Vpp SIM Card Interface 4.8.
Smart Machine Smart Decision 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.
Smart Machine Smart Decision Table 12: Pin description (Amphenol SIM card holder) Pin name Signal Description C1 SIM_VDD SIM card power supply C2 SIM_RST SIM card reset C3 SIM_CLK SIM card clock C5 GND Connect to GND C6 VPP Not connect C7 SIM_DATA SIM card data I/O 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.
Smart Machine Smart Decision C7 SIM_DATA SIM card data I/O C8 SIM_PRESENCE Detect SIM card presence 4.9 LCD Display/SPI Interface SIM968 provides a serial LCD display interface. It could also be used as SPI interface in the embedded AT application. For details about embedded AT application, please refer to document [7]. Note: This function is not supported in the standard firmware. If user wants this function, the firmware must be customized. Please contact SIMCom for more details. 4.
Smart Machine Smart Decision 4.11 ADC SIM968 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 15: ADC specification Parameter Min Typ Max Unit Voltage range 0 - 2.8 V ADC Resolution - 10 - bits Sampling rate - - 200K Hz 4.12 RI Behaviors Table 16: RI behaviors State RI response Standby High Voice call The pin is changed to low.
Smart Machine Smart Decision HIGH RI Establish the call Hang up the call LOW Idle Ring Figure 32: RI behaviour of data calling as a receiver Figure 33: 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 34: RI behaviour as a caller 4.13 Network Status Indication The NETLIGHT pin can be used to drive a network status indication LED.
Smart Machine Smart Decision Figure 35: Reference circuit of NETLIGHT 4.14 General Purpose Input/Output (GPIO) SIM968 provides up to 6 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 close to the NRESET pin is strongly recommended. A reference circuit is shown in the following figure. Figure 37: Reset reference design circuit NOTE: It is recommended to cut off the VBAT power supply directly instead of using external reset pin when SIM968 can not respond to the AT command “AT+CPOWD=1” and PWRKEY pin. 4.16 PWM SIM968 provides 3 PWMs which can be used to drive a vibrator, and a backlight LED for display or keyboard.
Smart Machine Smart Decision GPS_ANT PAD (PIN 79) GSM_ANT PAD (PIN59) Figure 38: The RF interface of module The customer’s main board under the GSM_ANT pad should be copper keep out. The customer’s GSM antenna can be located in the customer’s main board and connect to module’s GSM_ANT pad through microstrip line or other type RF trace which impendence must be controlled in 50Ω. To facilitate the antenna tuning and certification test, a RF connector and an antenna matching circuit should be added.
Smart Machine Smart Decision 5 5.1 GNSS Application Interface Power Management 5.1.1 GNSS Power Input The GPS_VCC supply range is from 2.8V to 4.3V, and it should be able to provide sufficient current up to 100mA. 5.1.2 z Starting GNSS Engine When GNSS power is first applied, The GNSS Engine goes into operation mode. 5.1.
Smart Machine Smart Decision Mode GPS_VCC V_BACKUP Internal LDO Main clock RTC clock Full on on On on on on Sleep on On on off on Backup on On off off on 5.1.5.1 Full on Mode The module will enter full on mode after first power up with factory configuration settings. Power consumption will vary depending on the amount of satellite acquisitions and number of satellites in track. This mode is also referenced as Full on, Full Power or Navigation mode.
Smart Machine Smart Decision Figure 40: Internal supply Antenna bias voltage Figure 41: External supply Antenna bias voltage 5.2 UART Interface SIM968 GNSS engine includes two UARTS (UART and UART1) interface for serial communication. The UART is as NMEA output and PMTK command input. The receiver (GPS_RXD) and transmitter (GPS_TXD) side of every port contains a 16-byte FIFO and has 256 bytes URAM. The baud rates are selectable and ranging from 4.8 to 921.6kbps through CoreBuilder tool.
Smart Machine Smart Decision The user should update the EPO files from the EPO server daily through the internet. Then the EPO data should send to the SIM968 by the HOST side. SIM68R has the short cold TTFF and warm TTFF, when the A-GPS is used. Note: For more information about EPO, please contact SIMCom sales. users can refer to document [20] for more information 5.4.
Smart Machine Smart Decision must be very careful in layout. Figure 42: GNSS antenna matching circuit In this figure, the components R101, C101 and C102 is used for antenna matching, the components’ value only can be got after the antenna tuning. Usually, matching components’ value is provided by antenna vendor, the default value of R101 is 0Ω, and users need to reserve the place of C101 and C102 without soldering. The traces in bold type should be treated as 50Ω impedance controlled line in PCB layout.
Smart Machine Smart Decision but once again, proper testing in an anechoic chamber is a mandatory requirement. These ceramic elements will need to be located near the end of the ground plane, and will require several millimeters of clearance between the closest component. It is important to note that use of a LP antenna will result in a minimum of 3dB of gain loss when compared to a RHCP antenna at a defined elevation. This is due to the right hand gain rule of antenna propagation.
Smart Machine Smart Decision Figure 43: Open circuir detection-A Figure 44: Open circuir detection-B If the antenna supply voltage is not derived from GPS_VANT_OUT, do not exceed the maximum voltage rating of AADET_N.(5V) SIM968_Hardware Design_V1.00 48 2013.02.
Smart Machine Smart Decision 6 Electrical, Reliability and Radio Characteristics 6.1 Absolute Maximum Ratings The absolute maximum ratings stated in following table are stress ratings under non-operating conditions. Stresses beyond any of these limits will cause permanent damage to SIM968. Table 20: Absolute maximum ratings of GSM * Symbol Parameter Min Typ Max Unit VBAT GSM Power supply voltage - - 5.5 V VI* Input voltage -0.3 - 3.
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 VIH High-level input voltage 2.4 - - V VIL Low-level input voltage - - 0.4 V VOH High-level output voltage 2.7 - - V VOL Low-level output voltage - - 0.1 V z 2 These parameters are for digital interface pins, such as keypad, GPIO, I C, UART, LCD, PWMs and DEBUG.
Smart Machine Smart Decision Symbol Parameter Min Typ Max Unit VO Output voltage 2.70 2.80 2.95 V IO Output current - - 10 mA Min Typ Max Unit 2.75 2.9 3.00 1.65 1.80 1.95 - - 10 mA 6.6 SIM_VDD Characteristics Table 27: SIM_VDD characteristics Symbol Parameter VO Output voltage IO Output current 6.7 VRTC Characteristics V Table 28: VRTC characteristics Symbol Parameter Min Typ Max Unit VRTC-IN VRTC input voltage 2.00 3.00 3.
Smart Machine Smart Decision Data mode GPRS(1Rx,1Tx) Data mode GPRS(4Rx,1Tx) Data mode GPRS(3Rx,2Tx) IVBAT-peak Peak current GSM 850 EGSM 900 DCS 1800 PCS 1900 GSM 850 EGSM 900 DCS 1800 PCS 1900 GSM 850 EGSM 900 DCS 1800 PCS 1900 During Tx burst PCL=15 76 PCL=5 240 PCL=12 110 PCL=19 83 PCL=0 170 PCL=7 95 PCL=15 80 PCL=5 270 PCL=12 150 PCL=19 120 PCL=0 210 PCL=7 130 PCL=15 115 PCL=5 435 PCL=12 185 PCL=19 130 PCL=0 320 PCL=7 155 PCL=15 122 mA mA mA mA mA
Smart Machine Smart Decision 6.10 Radio Characteristics 6.10.1 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 31: SIM968 GSM 900 and GSM 850 conducted RF output power GSM 900 and EGSM 850 PCL Tolerance (dB) for conditions Nominal output power (dBm) Normal Extreme 0-2 39 ±2 ±2.
Smart Machine Smart Decision 3 24 ±3 ±4 4 22 ±3 ±4 5 20 ±3 ±4 6 18 ±3 ±4 7 16 ±3 ±4 8 14 ±3 ±4 9 12 ±4 ±5 10 10 ±4 ±5 11 8 ±4 ±5 12 6 ±4 ±5 13 4 ±4 ±5 14 2 ±5 ±6 15-28 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 a
Smart Machine Smart Decision GSM850 869 ~ 894MHz 824 ~ 849 MHz EGSM900 925 ~ 960MHz 880 ~ 915MHz DCS1800 1805 ~ 1880MHz 1710 ~ 1785MHz PCS1900 1930 ~ 1990MHz 1850 ~ 1910MHz 6.11 Module label information The following figure marked the information of SIM968 module. Figure 45: Module label information Table 35: illustration of module label Item Description A Logo of SIMCom B Module name C Module part number Hardware number and software number included; ex.
Smart Machine Smart Decision Appendix A.
Smart Machine Smart Decision NMEA Messages SpecificationV1.00 [20] EPO-II_Format_Protocol _Customer EPO-II_Format and Protocol [21] CoreBuilder_User_Manua l_0_4 CoreBuilder User Manual B.
Smart Machine Smart Decision NMEA National Marine Electronics Association PAP Password Authentication Protocol PBCCH Packet Broadcast Control Channel PCB Printed Circuit Board PCL Power Control Level PCS Personal Communication System, also referred to as GSM 1900 PDU Protocol Data Unit PPP Point-to-point protocol QZSS Quasi-Zenith Satellites System RF Radio Frequency RMS Root Mean Square (value) RTC Real Time Clock RX Receive Direction RTCM Radio Technical Commission for Maritime
Smart Machine Smart Decision 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.
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 3252 3300 Fax: +86 21 3252 3301 URL: www.sim.com/wm SIM968_Hardware Design_V1.00 60 2013.02.
