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    SIM808_Hardware Design_V1.00 Smart Machine Smart Decision Document Title Version Date Status Document Control ID SIM808_Hardware_Design_V1.00 1.00 2014-03-27 Release SIM808_Hardware Design 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. 2014 SIM808_Hardware Design_V1.00 2 2014.03.27 Smart Machine Smart Decision Contents Contents.................................................................................................................................................................... 3 Version History ........................................................................................................................................................ 9 1 Introduction..................................................................................................................................................... 10 2 SIM808 Overview ........................................................................................................................................... 10 2.1 SIM808 Key Features............................................................................................................................. 10 2.2 Operating Modes .................................................................................................................................... 13 2.3 SIM808 Functional Diagram .................................................................................................................. 14 3 Package Information ...................................................................................................................................... 15 3.1 Pin out Diagram...................................................................................................................................... 15 3.2 Pin Description ....................................................................................................................................... 16 3.3 Package Dimensions............................................................................................................................... 18 4 GSM Application Interface ............................................................................................................................ 20 4.1 Power Supply.......................................................................................................................................... 20 4.1.1 Power Supply Pin................................................................................................................................ 21 4.1.2 Monitoring Power Supply ................................................................................................................... 22 4.2 Power on/down SIM808......................................................................................................................... 22 4.2.1 Power on SIM808 ............................................................................................................................... 22 4.2.2 Power down SIM808........................................................................................................................... 24 4.2.3 Reset Function..................................................................................................................................... 25 4.3 Power Saving Mode................................................................................................................................ 26 4.3.1 Function Mode .................................................................................................................................... 27 4.3.2 Sleep Mode (AT+CSCLK=1) ............................................................................................................. 27 4.3.3 Wake Up SIM808 from Sleep Mode (AT+CSCLK=1) ...................................................................... 27 4.4 Charging Interface .................................................................................................................................. 28 4.4.1 Battery Pack Characteristics................................................................................................................ 28 4.4.2 Recommended Battery Pack ............................................................................................................... 28 4.4.3 Implemented Charging Technique ...................................................................................................... 29 4.4.4 Operating Modes during Charging...................................................................................................... 29 4.4.5 Charger Requirements......................................................................................................................... 30 4.5 RTC Backup ........................................................................................................................................... 30 4.6 Serial Port and USB Interface ................................................................................................................ 31 4.6.1 Function of Serial Port ........................................................................................................................ 32 4.6.2 Serial Port............................................................................................................................................ 32 4.6.3 USB Interface...................................................................................................................................... 34 4.6.4 Software Upgrade and Debug ............................................................................................................. 35 4.7 RI Behaviors........................................................................................................................................... 35 4.8 Audio Interfaces ..................................................................................................................................... 36 4.8.1 Speaker Interface Configuration ......................................................................................................... 37 4.8.2 Microphone Interfaces Configuration ................................................................................................. 37 4.8.3 Audio Electronic Characteristics......................................................................................................... 38 4.8.4 TDD .................................................................................................................................................... 38 4.9 Bluetooth ................................................................................................................................................ 39 SIM808_Hardware Design_V1.00 3 2014.03.27 Smart Machine Smart Decision 4.9.1 Antenna Interface ................................................................................................................................ 39 4.10 SIM Card Interface ................................................................................................................................. 39 4.10.1 SIM Card Application...................................................................................................................... 40 4.10.2 SIM Card Design Consideration...................................................................................................... 41 4.10.3 Design Considerations for SIM Card Holder................................................................................... 41 4.11 PCM Interface ........................................................................................................................................ 43 4.11.1 PCM Multiplex Function ................................................................................................................. 43 4.11.2 PCM Interface.................................................................................................................................. 44 4.11.3 LCD Display/SPI Interface.............................................................................................................. 44 4.11.4 SD Card Interface ............................................................................................................................ 45 4.12 Keypad Interface .................................................................................................................................... 45 4.13 I2C BUS ................................................................................................................................................. 47 4.13.1 General Purpose Input/Output (GPIO) ............................................................................................ 48 4.14 ADC........................................................................................................................................................ 48 4.15 PWM ...................................................................................................................................................... 49 4.16 Network Status Indication ...................................................................................................................... 50 4.17 Operating Status Indication .................................................................................................................... 50 4.18 RF Synchronization Signal..................................................................................................................... 51 4.19 Antenna Interface ................................................................................................................................... 51 5 GPS Application Interface ............................................................................................................................. 52 5.1 GPS Operating Modes ............................................................................................................................ 52 5.2 GPS Power on/down Scenarios .............................................................................................................. 53 5.2.1 Power on GPS engine.......................................................................................................................... 53 5.2.2 Power down GPS engine..................................................................................................................... 53 5.3 GPS Antenna Interface ........................................................................................................................... 53 5.3.1 GPS Antenna Interface........................................................................................................................ 53 5.3.2 GPS Antenna Choice Consideration ................................................................................................... 53 6 Electrical, Reliability and Radio Characteristics......................................................................................... 54 6.1 Absolute Maximum Ratings................................................................................................................... 54 6.2 Recommended Operating Conditions..................................................................................................... 55 6.3 Digital Interface Characteristics ............................................................................................................. 55 6.4 SIM Card Interface Characteristics ........................................................................................................ 55 6.5 SIM_VDD Characteristics...................................................................................................................... 56 6.6 VDD_EXT Characteristics ..................................................................................................................... 56 6.7 VRTC Characteristics ............................................................................................................................. 56 6.8 Current Consumption (VBAT = 4V, GPS engine is powered down)...................................................... 56 6.9 Electro-Static Discharge ......................................................................................................................... 57 6.10 Radio Characteristics.............................................................................................................................. 58 6.10.1 Module RF Output Power................................................................................................................ 58 6.10.2 Module RF Receive Sensitivity ....................................................................................................... 59 6.10.3 Module Operating Frequencies........................................................................................................ 60 7 Manufacturing ................................................................................................................................................ 61 7.1 Top and Bottom View of SIM808........................................................................................................... 61 7.2 Typical Solder Reflow Profile ................................................................................................................ 61 7.3 The Moisture Sensitivity Level .............................................................................................................. 62 7.4 Baking Requirements ............................................................................................................................. 62 Appendix ................................................................................................................................................................ 63 SIM808_Hardware Design_V1.00 4 2014.03.27 Smart Machine Smart Decision A. Related Documents.......................................................................................................................................... 63 B. Terms and Abbreviations ................................................................................................................................. 64 C. Safety Caution ................................................................................................................................................. 65 Table Index TABLE 1: SIM808 GSM/GPRS ENGINE KEY FEATURES ......................................................................................... 10 TABLE 2: GPS ENGINE PERFORMANCE ................................................................................................................... 12 TABLE 3: CODING SCHEMES AND MAXIMUM NET DATA RATES OVER AIR INTERFACE ............................ 12 TABLE 4: OVERVIEW OF OPERATING MODES........................................................................................................ 13 TABLE 5: PIN DESCRIPTION ....................................................................................................................................... 16 TABLE 6: RECOMMENDED ZENER DIODE .............................................................................................................. 20 TABLE 7: ELECTRONIC CHARACTERISTIC OF THE RESET PIN.......................................................................... 26 TABLE 8: THE CURRENT CONSUMPTION OF FUNCTION MODES (BS-PA-MFRMS=5) ................................... 27 TABLE 9: SPECIFICATION OF RECOMMENDED BATTERY PACK........................................................................ 28 TABLE 10: SERIAL PORT AND USB PIN DEFINITION ............................................................................................. 31 TABLE 11: SERIAL PORT CHARACTERISTICS......................................................................................................... 31 TABLE 12: SERIAL PORT CHARACTERISTICS......................................................................................................... 34 TABLE 13: RI BEHAVIORS ........................................................................................................................................... 35 TABLE 14: AUDIO INTERFACE DEFINITION............................................................................................................ 36 TABLE 15: MICROPHONE INPUT CHARACTERISTICS........................................................................................... 38 TABLE 16: AUDIO OUTPUT CHARACTERISTICS .................................................................................................... 38 TABLE 17: SIM PIN DEFINITION................................................................................................................................. 40 TABLE 18: PIN DESCRIPTION (MOLEX SIM CARD HOLDER) .............................................................................. 42 TABLE 19: PIN DESCRIPTION (AMPHENOL SIM CARD HOLDER)....................................................................... 42 TABLE 20: PCM PIN DEFINITION ............................................................................................................................... 43 TABLE 21: PCM PIN SPECIFICATION......................................................................................................................... 43 TABLE 22: PCM MULTIPLEX FUNCTION .................................................................................................................. 43 TABLE 23: PIN DEFINITION OF THE KEYPAD INTERFACE................................................................................... 47 TABLE 24: KEYPAD MULTIPLEX FUNCTION........................................................................................................... 47 TABLE 25: PIN DEFINITION OF THE I2C ................................................................................................................... 48 TABLE 26: I2C MULTIPLEX FUNCTION .................................................................................................................... 48 TABLE 27: PIN DEFINITION OF THE GPIO................................................................................................................ 48 TABLE 28: PIN DEFINITION OF THE ADC................................................................................................................. 48 TABLE 29: ADC SPECIFICATION ................................................................................................................................ 49 TABLE 30: PIN DEFINITION OF THE PWM ............................................................................................................... 49 TABLE 31: BUZZER OUTPUT CHARACTERISTICS ................................................................................................. 49 TABLE 32: PWM MULTIPLEX FUNCTION................................................................................................................. 49 TABLE 33: PIN DEFINITION OF THE NETLIGHT ..................................................................................................... 50 TABLE 34: STATUS OF THE NETLIGHT PIN.............................................................................................................. 50 TABLE 35: PIN DEFINITION OF THE STATUS........................................................................................................... 50 TABLE 36: DEFINITION OF THE RF_SYNC PIN........................................................................................................ 51 TABLE 37: AT COMMANDS FOR GPS FUNCTION.................................................................................................... 52 TABLE 38: ABSOLUTE MAXIMUM RATINGS........................................................................................................... 54 TABLE 39: RECOMMENDED OPERATING CONDITIONS ....................................................................................... 55 TABLE 40: DIGITAL INTERFACE CHARACTERISTICS ........................................................................................... 55 TABLE 41: SIM CARD INTERFACE CHARACTERISTICS........................................................................................ 55 TABLE 42: SIM_VDD CHARACTERISTICS................................................................................................................ 56 SIM808_Hardware Design_V1.00 5 2014.03.27 Smart Machine Smart Decision TABLE 43: VDD_EXT CHARACTERISTICS ............................................................................................................... 56 TABLE 44: VRTC CHARACTERISTICS ....................................................................................................................... 56 TABLE 45: GSM CURRENT CONSUMPTION*............................................................................................................ 56 TABLE 46: THE ESD CHARACTERISTICS (TEMPERATURE: 25℃, HUMIDITY: 45 %) ....................................... 57 TABLE 47: SIM808 GSM 900 AND GSM 850 CONDUCTED RF OUTPUT POWER ................................................ 58 TABLE 48: SIM808 DCS 1800 AND PCS 1900 CONDUCTED RF OUTPUT POWER............................................... 58 TABLE 49: SIM808 CONDUCTED RF RECEIVE SENSITIVITY ............................................................................... 59 TABLE 50: SIM808 OPERATING FREQUENCIES....................................................................................................... 60 TABLE 51: MOISTURE CLASSIFICATION LEVEL AND FLOOR LIFE ................................................................... 62 TABLE 52: BAKING REQUIREMENTS ....................................................................................................................... 62 TABLE 53: RELATED DOCUMENTS ........................................................................................................................... 63 TABLE 54: TERMS AND ABBREVIATIONS................................................................................................................ 64 TABLE 55: SAFETY CAUTION..................................................................................................................................... 65 SIM808_Hardware Design_V1.00 6 2014.03.27 Smart Machine Smart Decision Figure Index FIGURE 1: SIM808 FUNCTIONAL DIAGRAM ........................................................................................................... 14 FIGURE 2: SIM808 PIN OUT DIAGRAM (TOP VIEW) ............................................................................................... 15 FIGURE 3: DIMENSIONS OF SIM808(UNIT: MM)................................................................................................ 18 FIGURE 4: RECOMMENDED PCB FOOTPRINT OUTLINE(UNIT: MM)............................................................ 19 FIGURE 5: REFERENCE CIRCUIT OF THE VBAT INPUT......................................................................................... 20 FIGURE 6: REFERENCE CIRCUIT OF THE LDO POWER SUPPLY ......................................................................... 20 FIGURE 7: REFERENCE CIRCUIT OF THE DC-DC POWER SUPPLY..................................................................... 21 FIGURE 8: VBAT VOLTAGE DROP DURING TRANSMIT BURST........................................................................... 21 FIGURE 9: THE MINIMAL VBAT VOLTAGE REQUIREMENT AT VBAT DROP .................................................... 22 FIGURE 10: POWERED ON/DOWN MODULE USING TRANSISTOR..................................................................... 22 FIGURE 11: POWERED ON/DOWN MODULE USING BUTTON ............................................................................. 22 FIGURE 12: TIMING OF POWER ON MODULE......................................................................................................... 23 FIGURE 13: TIMING OF POWER ON MODULE......................................................................................................... 23 FIGURE 14: TIMING OF POWER DOWN SIM808 BY PWRKEY .............................................................................. 24 FIGURE 15: RESET CIRCUIT........................................................................................................................................ 26 FIGURE 16: RESET TIMING SEQUENCE.................................................................................................................... 26 FIGURE 17: SIM808 WITH BATTERY CHARGER AND PACK CONNECTION....................................................... 28 FIGURE 18: RTC SUPPLY FROM CAPACITOR........................................................................................................... 30 FIGURE 19: RTC SUPPLY FROM NON-CHARGEABLE BATTERY ......................................................................... 30 FIGURE 20: RTC SUPPLY FROM RECHARGEABLE BATTERY .............................................................................. 30 FIGURE 21: SEIKO XH414H-IV01E CHARGE-DISCHARGE CHARACTERISTIC ................................................. 31 FIGURE 22: CONNECTION OF THE SERIAL PORT................................................................................................... 32 FIGURE 23: LEVEL CONVERTING BY RESISTOR.................................................................................................... 33 FIGURE 24: ISOLATION CIRCUIT BY DIODES ......................................................................................................... 33 FIGURE 25: TX LEVEL CONVERTING BY TRANSISTOR........................................................................................ 33 FIGURE 26: RX LEVEL CONVERTING BY TRANSISTOR ....................................................................................... 34 FIGURE 27: USB REFERENCE CIRCUIT .................................................................................................................... 34 FIGURE 28: RI BEHAVIOUR OF VOICE CALLING AS A RECEIVER...................................................................... 35 FIGURE 29: RI BEHAVIOUR OF DATA CALLING AS A RECEIVER........................................................................ 36 FIGURE 30: RI BEHAVIOUR OF URC OR RECEIVE SMS ........................................................................................ 36 FIGURE 31: RI BEHAVIOUR AS A CALLER ............................................................................................................... 36 FIGURE 32: SPEAKER REFERENCE CIRCUIT .......................................................................................................... 37 FIGURE 33: SPEAKER WITH AMPLIFIER REFERENCE CIRCUIT ......................................................................... 37 FIGURE 34 : MICROPHONE REFERENCE CIRCUIT................................................................................................. 37 FIGURE 35: BLUETOOTH ANTENNA MATCHING CIRCUIT ................................................................................. 39 FIGURE 36: REFERENCE CIRCUIT OF THE 8-PIN SIM CARD HOLDER............................................................... 40 FIGURE 37: REFERENCE CIRCUIT OF THE 6-PIN SIM CARD HOLDER............................................................... 40 FIGURE 38: MOLEX 91228 SIM CARD HOLDER ...................................................................................................... 41 FIGURE 39: AMPHENOL C707 10M006 5122 SIM CARD HOLDER......................................................................... 42 FIGURE 40: PCM REFERENCE CIRCUIT.................................................................................................................... 44 FIGURE 41: LCD REFERENCE CIRCUIT .................................................................................................................... 44 FIGURE 42: SD REFERENCE CIRCUIT ....................................................................................................................... 45 FIGURE 43: TRADITIONAL KEYPAD REFERENCE CIRCUIT................................................................................. 45 FIGURE 44: EXTENDED KEYPAD REFERENCE CIRCUIT ...................................................................................... 46 FIGURE 45: ENHANCE THE ESD PERFORMANCE OF KEYPAD CIRCUIT........................................................... 46 FIGURE 46: KEYPAD DETECTED ............................................................................................................................... 47 FIGURE 47: REFERENCE CIRCUIT OF PWM DRIVE BUZZER ............................................................................... 49 SIM808_Hardware Design_V1.00 7 2014.03.27 Smart Machine Smart Decision FIGURE 48: REFERENCE CIRCUIT OF NETLIGHT .................................................................................................. 50 FIGURE 49: RF_SYNC SIGNAL DURING TRANSMIT BURST ................................................................................ 51 FIGURE 50: GSM ANTENNA MATCHING CIRCUIT ................................................................................................. 51 FIGURE 51: GPS ANTENNA MATCHING CIRCUIT................................................................................................... 53 FIGURE 52: TOP AND BOTTOM VIEW OF SIM808 ................................................................................................... 61 FIGURE 53: TYPICAL SOLDER REFLOW PROFILE ................................................................................................. 61 SIM808_Hardware Design_V1.00 8 2014.03.27 Version History Date 2014-03-27 Version 1.00 Description of change Origin Smart Machine Smart Decision Author ShengWu.Sun Xuegang.Wang SIM808_Hardware Design_V2.00 8 2014.03.27 1 Introduction Smart Machine Smart Decision This document describes SIM808 hardware interface in great detail. This document can help user to quickly understand SIM808 interface specifications, electrical and mechanical details. With the help of this document and other SIM808 application notes, user guide, users can use SIM808 to design various applications quickly. 2 SIM808 Overview Designed for global market, SIM808 is integrated with a high performance GSM/GPRS engine, a GPS engine and a BT engine. The GSM/GPRS engine is a quad-band GSM/GPRS module that works on frequencies GSM 850MHz, EGSM 900MHz, DCS 1800MHz and PCS 1900MHz. SIM808 features GPRS multi-slot class 12/ class 10 (optional) and supports the GPRS coding schemes CS-1, CS-2, CS-3 and CS-4. The GPS solution offers bestin-class acquisition and tracing sensitivity, Time-To-First-Fix (TTFF) and accuracy. With a tiny configuration of 24*24*2.6mm, SIM808 can meet almost all the space requirements in user applications, such as M2M, smart phone, PDA, tracker and other mobile devices. SIM808 has 68 SMT pads, and provides all hardware interfaces between the module and customers’ boards. z Support 4*4*2 keypads. z One full modem serial port. z One USB, the USB interfaces can debug, download software. z Audio channels which include a microphone input and a receiver output. z One SIM card interface. z Charging interface. z Programmable general purpose input and output. z Support Bluetooth function. z Support PWM and ADC. z PCM/SPI/SD card interface, only one function can be accessed synchronously. (Default function is PCM). SIM808 is designed with power saving technique so that the current consumption is as low as 1mA in sleep mode (GPS engine is powered down). SIM808 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 SIM808 Key Features Table 1: SIM808 GSM/GPRS engine key features Feature Power supply Power saving Charging Frequency bands Implementation 3.4V ~ 4.4V Typical power consumption in sleep mode is 1mA ( BS-PA-MFRMS=9, GPS engine is powered down ) Supports charging control for Li-Ion battery z SIM808 Quad-band: GSM 850, EGSM 900, DCS 1800, PCS 1900. SIM808 SIM808_Hardware Design_V1.00 10 2014.03.27 Smart Machine Smart Decision Transmitting power GPRS connectivity Temperature range Data GPRS CSD USSD SMS 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 12(default) z GPRS multi-slot class 1~12 (optional) z Normal operation: -40℃ ~ +85℃ z Storage temperature -45℃~ +90℃ z GPRS data downlink transfer: max. 85.6 kbps z GPRS data uplink transfer: max. 85.6 kbps z Coding scheme: CS-1, CS-2, CS-3 and CS-4 z PAP protocol for PPP connect z Integrate the TCP/IP protocol. z Support Packet Broadcast Control Channel (PBCCH) z CSD transmission rates:2.4,4.8,9.6,14.4 kbps z Support CSD transmission z Unstructured Supplementary Services Data (USSD) support z MT, MO, CB, Text and PDU mode z SMS storage: SIM card 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 USB interface 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 115200bps. USB interface: z Can be used as debugging and firmware upgrading. Phonebook management Support phonebook types: SM, FD, LD, RC, ON, MC. SIM application toolkit GSM 11.14 Release 99 Real time clock Support RTC Alarm function Can be set by AT command Physical characteristics Size: 24*24*2.6mm Weight: 3.5g SIM808_Hardware Design_V1.00 11 2014.03.27 Firmware upgrade Firmware upgrading by USB interface. Smart Machine Smart Decision Table 2: GPS engine Performance Parameter Description Horizontal Position Accuracy(1) Velocity Accuracy(2) Acceleration Accuracy Timing Accuracy Dynamic Performance Time To First Fix(3) Sensitivity Receiver Autonomous Without Aid DGPS Without Aid DGPS Maximum Altitude Maximum Velocity Maximum Acceleration Hot start Warm start Cold start Autonomous acquisition(cold start) Re-acquisition Tracking Channels Update rate Tracking L1, CA Code Performance Min Type Max Unit <2.5 m 0.1 m/s 0.05 m/s 0.1 m/s2 0.05 m/s2 10 nS 18000 m 515 m/s 4 G 1 s 28 s 30 s -147 dBm -159 dBm -165 dBm 22/66 5 Hz Protocol support NMEA Power Acquisition 42 mA consumption(4) Continuous tracking 24 mA (1) 50% 24hr static, -130dBm (2) 50% at 30m/s (3) GPS signal level: -130dBm (4) Single Power supply 3.8V@-130dBm,GSM IDLE Table 3: Coding schemes and maximum net data rates over air interface 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 SIM808_Hardware Design_V1.00 12 2014.03.27 2.2 Operating Modes Smart Machine Smart Decision The table below summarizes the various operating modes of SIM808. Table 4: 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). Charge The mode support charge function (Default is not support). 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. SIM808_Hardware Design_V1.00 13 2014.03.27 2.3 SIM808 Functional Diagram The following figure shows a functional diagram of SIM808: z The GSM baseband engine z The GPS engine z Flash z The GSM radio frequency part z The antenna interface z The other interfaces Smart Machine Smart Decision Figure 1: SIM808 functional diagram SIM808_Hardware Design_V1.00 14 2014.03.27 3 Package Information 3.1 Pin out Diagram Smart Machine Smart Decision Figure 2: SIM808 pin out diagram (Top view) SIM808_Hardware Design_V1.00 15 2014.03.27 3.2 Pin Description Smart Machine Smart Decision Table 5: Pin description Pin name Pin number I/O Description Comment Power supply VBAT 4,5,6 SIM808 supplies 3 VBAT pins, and the power Zener diode is range is from 3.4V to 4.4V. Power supply Strongly I should provide sufficient current so that the recommended to anti module can work normally; the peak current is surge on VBAT. nearly 2A. VRTC 17 I/O Power supply for RTC It is recommended to connect VRTC to a battery or a capacitor (e.g. 4.7uF). VDD_EXT 7 O 2.8V power output Keep floating if unused. GND 1,2,3,18,28,34 ,36,40,51,52,5 4,64,65,67,68 Ground Recommend connecting 1,2,3pin to the power GND. Power on/off PWRKEY 8 PWRKEY should be pulled low at least 1 Internally pulled up to I second and then released to power on/down the VBAT. module. Audio interface MIC1P 19 MIC1N 20 SPK1P 21 SPK1N 22 I Differential audio input O Differential audio output Keep floating if unused. PCM interface PCM_OUT 48 O PCM_IN 47 PCM_SYNC 45 I PCM interface for audio O Keep floating if unused. PCM_CLK 46 I Keypad interface COL3 59 I COL2 60 I COL1 61 I COL0 62 I Support up to 32 buttons (4*4*2) ROW3 55 O ROW2 56 O Keep floating if unused. (COL0 can not be pulled down). ROW1 57 O ROW0 58 O SIM808_Hardware Design_V1.00 16 2014.03.27 GPIO GPIO5 43 GPIO6 44 NETLIGHT 50 STATUS 49 Serial port DTR 9 RI 10 DCD 11 CTS 12 RTS 13 TXD 14 RXD 15 USB interface VBUS 25 USB_DP 26 USB_DM 27 ADC ADC1 23 ADC2 24 PWM PWM1 42 PWM2 41 I2C SDA 38 SCL 39 SIM interface SIM_VDD 29 SIM_DATA 30 SIM_CLK 31 SIM_RST 32 SIM_PRESENCE 33 Antenna GSM_RF_IN 66 ANT_BT 53 GPS_RF_IN 35 RF synchronization RF_SYNC 63 SIM808_Hardware Design_V1.00 Smart Machine Smart Decision I/O Programmable general purpose input and I/O output. O Network status O Power on status Can not multiplex with GPIO function. I Data terminal ready O Ring indicator O Data carrier detect O Clear to send I Request to send O Transmit data I Receive data Keep floating if unused. I I/O Debug and firmware upgrading I/O Keep floating if unused. I 10 bit general analog to digital converter Keep floating if unused. O Pulse-width modulation, multiplex with GPIO4. Keep floating if O Pulse-width modulation, multiplex with GPIO3. unused. I/O I2C serial bus data O I2C serial bus clock Internal pulled up to 2.8V via 4.7KΩ Voltage supply for SIM card. Support 1.8V or All signals of SIM O 3V for SIM card interface should be I/O SIM data input/output O SIM clock O SIM reset protected against ESD with a TVS diode array. I SIM card detection I/O Connect GSM antenna I/O Connect Bluetooth antenna I Connect GPS antenna Impendence must be controlled to 50Ω. Impendence must be controlled to 50Ω. Impendence must be controlled to 50Ω. O RF burst synchronous signal 17 Do not pull up 2014.03.27 Other signal RESET 16 1PPS 37 Smart Machine Smart Decision I Reset input(Active low) Time Mark outputs timing pulse related to I If unused, keep open. receiver time 3.3 Package Dimensions Figure 3: Dimensions of SIM808(Unit: mm) SIM808_Hardware Design_V1.00 18 2014.03.27 Smart Machine Smart Decision Figure 4: Recommended PCB footprint outline(Unit: mm) SIM808_Hardware Design_V1.00 19 2014.03.27 4 GSM Application Interface Smart Machine Smart Decision 4.1 Power Supply The power supply range of SIM808 is from 3.4V to 4.4V.Recommended voltage is 4.0V.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. Increase the 33PF and 10PF capacitors can effectively eliminate the high frequency interference. A 5.1V/500mW Zener diode is strongly recommended, the diode can prevent chip from damaging by the voltage surge. These capacitors and Zener diode should be placed as close as possible to SIM808 VBAT pins. Figure 5: Reference circuit of the VBAT input Table 6: Recommended Zener diode Vendor 1 On semi 2 Prisemi 3 Prisemi 4 Vishay 5 Crownpo Part number MMSZ5231BT1G PZ3D4V2H PZ5D4V2H MMSZ4689-V CDZ55C5V1SM Power(watts) 500mW 500mW 500mW 500mW 500mW Packages SOD123 SOD323 SOD523 SOD123 0805 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. Figure 6: Reference circuit of the LDO power supply SIM808_Hardware Design_V1.00 20 2014.03.27 Smart Machine Smart Decision 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 7: Reference circuit of the DC-DC power supply The single 3.7V Li-ion cell battery can be connected to SIM808 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. Notes:The module do not support for charging Ni-Cd or Ni-MH battery. 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. Figure 8: VBAT voltage drop during transmit burst 4.1.1 Power Supply Pin The 3 VBAT pins are used for power input, and pin 4, 5, 6 should be connected to the power GND. VRTC pin is power supply of the RTC circuit in the module. VDD_EXT will output 2.8V when module powered up. When designing the power supply in user’s application, pay special attention to power losses. Ensure that the input voltage never drop below 3.0V even when current consumption rises to 2A in the transmit burst. If the power voltage drops below 3.0V, 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. SIM808_Hardware Design_V1.00 21 2014.03.27 Smart Machine Smart Decision Figure 9: The minimal VBAT voltage requirement at VBAT drop 4.1.2 Monitoring Power Supply The AT command “AT+CBC” can be used to monitor the VBAT voltage. For detail, please refer to document [1]. 4.2 Power on/down SIM808 4.2.1 Power on SIM808 4.2.1.1 Turn on SIM808 Using the PWRKEY Pin (Power on) User can power on SIM808 by pulling down the PWRKEY pin for at least 1 second and release. This pin is already pulled up to VBAT in the module internal, so external pull up is not necessary. Reference circuit is shown as below. Figure 10: Powered on/down module using transistor Figure 11: Powered on/down module using button SIM808_Hardware Design_V1.00 22 2014.03.27 The power on scenarios is illustrated as following figure. Smart Machine Smart Decision Figure 12: Timing of power on module When power on procedure is completed, SIM808 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 SIM808 is powered on. For details, please refer to the chapter “AT+IPR” in document [1]. 4.2.1.2 Turn on the SIM808 using the VBUS Signal The SIM808 will be automatically turned on when a charger is connected to VBUS pin, the switched-off SIM808 of which VBAT pin voltage is greater than 3.4V. SIM808 will power up. Figure 13: Timing of power on module SIM808_Hardware Design_V1.00 23 2014.03.27 4.2.2 Power down SIM808 Smart Machine Smart Decision SIM808 will be powered down in the following situations: z Normal power down procedure: power down SIM808 by the PWRKEY pin. z Normal power down procedure: power down SIM808 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. NOTE:The VBUS pin should not be charged, otherwise ,the module will not be powered down. 4.2.2.1 Power down SIM808 by the PWRKEY Pin User can power down SIM808 by pulling down the PWRKEY pin for at least 1 second and release. Please refer to the power on circuit. The power down scenario is illustrated in following figure. Figure 14: Timing of power down SIM808 by PWRKEY This procedure makes the module log off from the network and allows the software to enter into a secure state to save data before completely shut down. Before the completion of the power down procedure, the module will send URC: NORMAL POWER DOWN At this moment, AT commands can not be executed any more, and only the RTC is still active. Power down mode can also be indicated by STATUS pin, which is at low level at this time. 4.2.2.2 Power down SIM808 by AT Command SIM808 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. SIM808_Hardware Design_V1.00 24 2014.03.27 For detail about the AT command “AT+CPOWD”, please refer to document [1] 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 ≤ 3.5V, the following URC will be reported: UNDER-VOLTAGE WARNNING If the voltage ≥ 4.3V, the following URC will be reported: OVER-VOLTAGE WARNNING If the voltage < 3.4V, the following URC will be reported, and the module will be automatically powered down. UNDER-VOLTAGE POWER DOWN If the voltage > 4.4V, the following URC will be reported, and the module will be automatically powered down. OVER-VOLTAGE POWER DOWN At this moment, AT commands can not be executed any more, and only the RTC is still active. Power down mode can also be indicated by STATUS pin, which is at low level at this time. 4.2.2.4 Over-temperature or Under-temperature Power down The module will constantly monitor the temperature of the module, If the temperature > +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]. 4.2.3 Reset Function SIM808 also has a RESET pin (pin 16) used to reset the module. This function is used as an emergency reset only when AT command “AT+CPOWD=1” and the POWER_ON pin has no effect. User can pull the RESET pin to ground, then the module will reset. This pin is already isolated in the module, so the external isolation is not necessary. Following figure is internal circuit of the RESET pin. SIM808_Hardware Design_V1.00 25 2014.03.27 Smart Machine Smart Decision Figure 15: Reset Circuit The typical value of RESET pin high level is 2.8V, so for the 3V or 3.3V, customer could use MCU’s GPIO to driver this pin directly, resistor in serial the RESET signal could enhance the ESD performance but the value should not be too high, otherwise the level of RESET could be lower than threshold value; RESET hardware parameters can refer to the following table. Table 7: Electronic characteristic of the RESET Pin Pin name RESET Symbol VIH VIL Tpull down Min Typ 2.7 2.8 - - 105 Max Unit 2.9 V 0.6 V - mS The reset scenarios are illustrated in the following figures. Figure 16: Reset timing sequence 4.3 Power Saving Mode User can control SIM808 module to enter or exit the sleep mode (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), SIM808 will enter sleep mode automatically. In this mode, SIM808 can still receive paging or SMS from network but the serial port is not accessible. Note: Customer must shut off the power supply of GPS, and then the AT commands about the power saving mode can be executed correctly, and the current consumption will be lower. SIM808_Hardware Design_V1.00 26 2014.03.27 4.3.1 Function Mode Smart Machine Smart Decision 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 AT+CFUN=0: minimum functionality. z AT+CFUN=1: full functionality (default). z AT+CFUN=4: flight mode (disable RF function). Table 8: The current consumption of function modes (BS-PA-MFRMS=5) Current consumption(uA) (CSCLK=1) 0 869.5 1 1400 4 922.5 Minimum functionality mode minimizes the current consumption to the lowest level. If SIM808 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]. 4.3.2 Sleep Mode (AT+CSCLK=1) When the GPS function is shut off, user can control SIM808 module to enter or exit the sleep mode (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), SIM808 will enter sleep mode automatically. In this mode, SIM808 can still receive paging or SMS from network but the serial port is not accessible. Note: For SIM808, it requests to set AT command “AT+CSCLK=1” and ensure DTR at high level to enable the sleep mode ; the default value is 0, which can not make the module to enter sleep mode. For more details please refer to document [1]. 4.3.3 Wake Up SIM808 from Sleep Mode (AT+CSCLK=1) When SIM808 is in sleep mode (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. z Receive a voice or data call from network. z Receive a SMS from network. z Receive external interrupt z Charge VBUS pin SIM808_Hardware Design_V1.00 27 2014.03.27 4.4 Charging Interface Smart Machine Smart Decision SIM808 has integrated a charging circuit inside the module for Li-Ion batteries charging control, which make it very convenient for user’s applications that support battery charging. A common connection is shown in the following figure: 5V VBUS VBAT M odule B a tte ry Pack Figure 17: SIM808 with battery charger and pack connection 4.4.1 Battery Pack Characteristics SIM808 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. z The battery pack should have a protection circuit to avoid overcharging, deep discharging and over-current, and the circuit should be insensitive to pulsed current. z The internal resistance of the battery pack including protection circuit should be as low as possible. Its recommended value does not exceed 150mΩ. z The battery pack must be protected from reverse pole connection. On the SIM808, the build-in circuit of the power management chipset monitors the supply voltage constantly. Once the Under-voltage is detected, the SIM808 will be powered down automatically. 4.4.2 Recommended Battery Pack Following is the specification of recommended battery pack: Table 9: Specification of recommended battery pack Items Battery type Manufacturer Normal voltage Capacity Charge Voltage Description Li-ion Jiade Energy Technology 3.7V NORMAL 1100mAh 4.200±0.050V SIM808_Hardware Design_V1.00 28 2014.03.27 Max Charge Current Charge Method Max Discharge Current Discharge Cut-off Voltage Internal resistance Smart Machine Smart Decision 1.0C CC / CV (Constant Current / Constant Voltage) 1.0C (for continuous discharging mode) 3.0V/ cell Initial≤150mΩ 4.4.3 Implemented Charging Technique SIM808 has battery charging function, but default function is not support for charging, the customer should input AT command to enable charging function. There are two pins related to the battery charging function: there are VBUS, VBAT and pins. The VBUS Pin is driven by an external voltage (AC adapter or USB host), system can use this Pin to detect a charger supply and provide most charging current through SIM808 module to battery when charging is in fast charge state. VBAT pin gives charging current to external battery from SIM808 module. It is very simple to implement charging function, user just needs to connect the charger to the VBUS Pin and connect the battery to the VBAT Pin. SIM808 battery charging happens after detecting charger supply and the presence of battery. If there is no charger supply or no battery present, charging function will not be enabled. Normally, there are three states in the whole charging procedure. z DDLO charge (Pull-up mode) and UVLO charge (Pre-charge mode); z Constant current mode (CC); z Constant voltage mode and over-voltage protection(OV) DDLO charge and UVLO charge: DDLO is the state of battery when its voltage is under 2.2V. And UVLO means the battery voltage is less than 3.3V and more than 2.2V. The battery is not suitable for fast charging when its condition is DDLO or UVLO. The SIM808 provides a small constant current to the battery when the battery is between DDLO and UVLO. In DDLO charging state, SIM808 gives out pu1se 70mA current to the battery. And in UVLO charging state, SIM808 provides about 200mA (AC<7V) or 70mA (USB mode) current to the battery. DDLO charging terminates when the battery voltage reaches 2.2V. UVLO charging terminates when the battery voltage is up to 3.4V. Both DDLO and UVLO charge are controlled by the SIM808 hardware only. Constant current mode (CC): As the battery voltage is charged up and over3.4V, the SIM808 will enter CC mode. The CC mode charging current can be set from 70 to 800mA by the software. Constant voltage mode (CV) and over-voltage protection (OV): As the battery is charged up and over 4.05V, the SIM808 will enter CV mode. While the batter voltage actually reaches 4.2V, the charging current is gradually decreased step by step until stop charging. 4.4.4 Operating Modes during Charging The battery can be charged during various operating mode. That means that charging can be in progress while SIM808 is in Normal mode (SLEEP, IDLE, TALK, GPRS IDLE or GPRS DATA mode). In this case the voltage supply should be sufficient. Here Charging in Normal mode is named as Charge mode. If the charger is connected to the module’s VBUS Pin and the valid battery is connected to the VBAT Pin while SIM808 is in POWER DOWN mode, SIM808 will auto power up. SIM808_Hardware Design_V1.00 29 2014.03.27 4.4.5 Charger Requirements Smart Machine Smart Decision Following is the requirements of charger for SIM808: z Simple transformer power plug z Output voltage: 5.0V~7V z Minimum supply current: 800mA z A 10V peak voltage is allowed for maximum 1ms when charging current is switched off. z A 1.6A peak current is allowed for maximum 1ms when charging current is switched on. 4.5 RTC Backup Current input for RTC when the VBAT is not supplied for the system. Current output for backup battery when the VBAT power supply is in present and the backup battery is in low voltage state. The RTC power supply of module can be provided by an external capacitor or a battery (non-chargeable or rechargeable) through the VRTC. The following figures show various reference circuits for RTC back up. z External capacitor for RTC Figure 18: RTC supply from capacitor z Non-chargeable battery for RTC Figure 19: RTC supply from non-chargeable battery z Rechargeable battery for RTC Figure 20: RTC supply from rechargeable battery SIM808_Hardware Design_V1.00 30 2014.03.27 Smart Machine Smart Decision 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 21: Seiko XH414H-IV01E charge-discharge characteristic 4.6 Serial Port and USB Interface SIM808 provides one unbalanced asynchronous serial port. The module is designed as a DCE (Data Communication Equipment). The following figure shows the connection between module and client (DTE). Table 10: Serial port and USB pin definition Name Pin number Function DTR 9 Data terminal ready RI 10 Ring indicator DCD 11 Data carrier detect Serial port CTS 12 Clear to send RTS 13 Request to send TXD 14 Transmit data RXD 15 Receive data VBUS 25 USB USB_DP 26 interface USB_DM 27 USB power supply USB data line plus USB data line minus Note: Hardware flow control is disabled by default. The AT command “AT+IFC=2,2” can enable hardware flow control .The AT command “AT+IFC=0,0”can disable hardware flow control. For more details, please refer to document [1]. Table 11: Serial port characteristics Symbol Min Max Unit VIL 0 0.3 V VIH 2.5 2.8 V VOL 0 0.1 V VOH 2.7 2.8 V SIM808_Hardware Design_V1.00 31 2014.03.27 4.6.1 Function of Serial Port Smart Machine Smart Decision 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.. 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, 57600 and 115200bps z The default setting is autobauding. Autobauding allows SIM808 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, firstly, user must send character “A” or “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 SIM808 is powered on. 4.6.2 Serial Port The following figure shows the connection between module and client (DTE). Figure 22: Connection of the serial port If the voltage of UART is 3.3V, the following reference circuits are recommended. If the voltage is 3.0V, please SIM808_Hardware Design_V1.00 32 2014.03.27 change the resistors in the following figure from 5.6K to 14K. Smart Machine Smart Decision Figure 23: Level converting by resistor If the voltage of UART is 3V or3.3V, user also can use following reference circuits: Figure 24: Isolation circuit by diodes Note: when a diode used to isolate voltage cross, customer should notice that there’s voltage drop on the diode. And the signal’s voltage level should meet the customer’s electrical character. The recommend diode is Schottky diode e.g. RB551V-30TE-17 and SDM20U40. If the voltage of UART is 5V on customer side, customer can use the following reference circuits : Figure 25: TX level converting by transistor SIM808_Hardware Design_V1.00 33 2014.03.27 Module VDD_EXT RXD 4.7K 4.7K VDD_EXT Smart Machine Smart Decision Customer MCUVDD 47K MCUTXD Figure 26: RX level converting by transistor Note: The recommend Transistors’ part numbers are 2SC4617TLR and PBHV8115Z. when update firmware via the TXD/RXD circuit as figure 25 and figure 26 shows, customer should make sure the VDD_EXT has voltage output, or a external LDO should be added to power VDD_EXT. 4.6.3 USB Interface USB interface supports software debug function. When power on the module, connect VBUS, USB_DP, USB_DM and GND to PC, then install the driver successfully, a UART port could be recognized by the PC, customer could achieve the software Debug purpose with this UART port. The following diagram is recommended: Figure 27: USB reference circuit The maximum allowable cap load of TVS on USB data line should be less than 5pF (e.g. ESD9L5.0ST5G and ESD9M5.0ST5G). The USB_DP and USB_DM should be routed in differential traces. Note: please reserve the USB interface or test point for debug. Table 12: Serial port characteristics Pin Min Typ VBUS 4.3 5 Max Unit 7 V SIM808_Hardware Design_V1.00 34 2014.03.27 4.6.4 Software Upgrade and Debug Smart Machine Smart Decision Only USB and interface can be used for firmware upgrade. If customer upgrading firmware via the USB port, SIM808 must be powered first, then connect VBUS, USB_DP, USB_DM and GND to PC. There is no need to operate PWRKEY pin in the whole procedure, when SIM808 detects VBUS and could communicate normally by USB_DP and USB_DM, module will enter USB download mode automatically. Note: When only USB_DP and USB_DM connected, no VBUS, customer need to pull down COL0 before power on the module, then press the PWRKEY button, the module will enter download mode; The serial port and the debug port support the CMOS level. If user connects the module to the computer, the level shifter should be added between the DCE and DTE. For details about software upgrading, please refer to document [4]. 4.7 RI Behaviors Table 13: RI Behaviors State RI response Standby High Voice call The pin is changed to low. When any of the following events occur, the pin will be changed to high: (1)Establish the call (2)Hang up the call Data call SMS The pin is changed to low. When any of the following events occur, the pin will be changed to high: (1)Establish the call (2)Hang up the call The pin is changed to low, and kept low for 120ms when a SMS is received. Then it is changed to high. URC 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 [10]. The behavior of the RI pin is shown in the following figure when the module is used as a receiver. Figure 28: RI behaviour of voice calling as a receiver SIM808_Hardware Design_V1.00 35 2014.03.27 Smart Machine Smart Decision Figure 29: RI behaviour of data calling as a receiver Figure 30: RI behaviour of URC or receive SMS However, if the module is used as caller, the RI will remain high. Please refer to the following figure. HIGH RI LOW Idle Ring Establish Hang up Idle the call the call Figure 31: RI behaviour as a caller 4.8 Audio Interfaces SIM808 provides one analog input, which could be used for electret microphone. The module also provides one analog output. The output can directly drive 32Ω receiver. Table 14: Audio interface definition Audio channel Pin name MIC1P MIC1N SPK1P SPK1N Pin number 19 20 21 22 Function Main Audio input positive Main Audio input negative Main Audio output positive Main Audio output negative “AT+CMIC” is used to adjust the input gain level of microphone. “AT+SIDET” is used to set the side-tone level. In addition, “AT+CLVL” is used to adjust the output gain level. For more details, please refer to document [1] SIM808_Hardware Design_V1.00 36 2014.03.27 Smart Machine Smart Decision 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. 4.8.1 Speaker Interface Configuration MODULE SPK1P The lines in bold type should be accorded to differential signal layout rules SPK1N These components should be placed to speaker as close as possible 10pF 10pF 10pF ESD 33pF ANTI 33pF ESD 33pF ANTI Figure 32: Speaker reference circuit Figure 33: Speaker with amplifier reference circuit 4.8.2 Microphone Interfaces Configuration Figure 34 : Microphone reference circuit SIM808_Hardware Design_V1.00 37 2014.03.27 4.8.3 Audio Electronic Characteristics Smart Machine Smart Decision Table 15: Microphone input characteristics Parameter Min Typ Max Unit Mic biasing voltage 1.9 2.2 V Working Current 2 mA Input impedance(differential) 13 20 27 KΩ Idle channel noise -67 dBm Input level:-40dBm0 29 dB SINAD Input level:0dBm0 69 dB Table 16: Audio output characteristics parameter Normal output Conditions Min RL=32 Ω receiver - Typ Max Unit 90 - mW 4.8.4 TDD GSM signal could interfere audio by coupling or conducting. Coupling noise could be filtered by adding 33 pF and 10pF capacitor over audio lines.33pF capacitor could eliminate noise from GSM900MHz, while 10pF capacitor could eliminate noise from DCS1800MHz frequency. Coupling noise has great relatives with PCB layout. Under some scenarios, TDD noise from GSM 900MHz frequency affects heavily, but some different story is from GSM1800MHz fervency, so customer should develop this filter solution according to field test result. GSM antenna is the key coupling interfering source of TDD noise. Pay attention to the layout of audio lines which should be far away from RF cable & antenna and VBAT pin. The bypass capacitor for filtering should be placed near module and another group placed near to connector. Conducting noise is mainly caused by the VBAT drop. If Audio PA was powered by VBAT directly, then there will be some cheep noise from SPK output easily. So, it's better to put big capacitor and ferrite bead near audio PA input. TDD noise has something to do with GND signal surely. If GND signal issued not good, lots of high-frequency noise will interfere MIC and speaker over bypass capacitor. So, take care of GND well during PCB layout. SIM808_Hardware Design_V1.00 38 2014.03.27 4.9 Bluetooth Smart Machine Smart Decision SIM808 supports Bluetooth function, customer only needs to design the Bluetooth antenna, and then customer can operate Bluetooth conveniently by AT commands. For the detail commands about Bluetooth please refer to document [1] z Fully compliant with Bluetooth specification3.0 + EDR z Support operation with GPS and GSM/GPRS worldwide radio systems z Fully integrated PA provides 10dbm output power z Up to 4 simultaneous active ACL links z Support sniff mode Support PCM interface and built-in programmable transcoders for liner voice with transmission. 4.9.1 Bluetooth Antenna Interface The module provides a Bluetooth antenna interface named ANT_BT. External antenna must be matched properly to achieve best performance, so the matching circuit is necessary, the connection is recommended as the following figure: Figure 35: Bluetooth antenna matching circuit R201, C201, C202 are the matching circuit, the values depend on antenna debug result. Normally R201 is 0Ω, C201 and C202 are not mounted. 4.10 SIM Card Interface The SIM interface complies with the GSM Phase 1 specification and the new GSM Phase 2+ specification for FAST 64 kbps SIM card. Both 1.8V and 3.0V SIM card are supported. The SIM interface is powered from an internal regulator in the module. SIM808_Hardware Design_V1.00 39 2014.03.27 4.10.1 SIM Card Application Smart Machine Smart Decision Table 17: SIM pin definition Name Pin SIM_VDD 29 SIM_DATA 30 SIM_CLK 31 SIM_RST 32 SIM_PRE 33 function Voltage supply for SIM card. Support 1.8V or 3V SIM card SIM data input/output SIM clock SIM reset SIM card detection It is recommended to use an ESD protection component such as ON (http://onsemi.com ) SMF12CT1G. 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. Figure 36: 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 37: Reference circuit of the 6-pin SIM card holder SIM808_Hardware Design_V1.00 40 2014.03.27 Smart Machine Smart Decision 4.10.2 SIM Card Design Consideration SIM card circuit is susceptible to interference, causing the SIM card failures or some other situations, so it is strongly recommended to follow these guidelines while designing: z Make sure that SIM card holder should far away from GSM antenna while in PCB layout. z SIM traces should keep away from RF lines, VBAT and high-speed signal lines. z The traces should be as short as possible. z Keep SIM holder’s GND connect to main ground directly. z Shielding the SIM card signal by ground well. z Recommended to place a 1uF capacitor on VSIM line and keep close to the holder. Add some TVS and the parasitic capacitance should not exceed 50pF, and 22Ω resistor in serials the SIM signal could enhance ESD protection. 4.10.3 Design Considerations for SIM Card Holder 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. Figure 38: Molex 91228 SIM card holder SIM808_Hardware Design_V1.00 41 2014.03.27 Table 18: Pin description (Molex SIM card holder) Pin name C1 C2 C3 C3 C5 C6 C7 C8 Signal SIM_VDD SIM_RST SIM_CLK GND GND VPP SIM_DATA SIM_PRE 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 Smart Machine Smart Decision 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. Figure 39: Amphenol C707 10M006 5122 SIM card holder Table 19: Pin description (Amphenol SIM card holder) Pin name Signal C1 VSIM C2 SIM_RST C3 SIM_CLK C5 GND C6 VPP C7 SIM_DATA SIM808_Hardware Design_V1.00 Description SIM card power supply SIM card reset SIM card clock Connect to GND Not connect SIM card data I/O 42 2014.03.27 Smart Machine Smart Decision 4.11 PCM Interface SIM808 provides PCM interface. Table 20: PCM pin definition Pin name Pin number Description PCM_OUT 48 PCM data output PCM_IN 47 PCM data input PCM_SYNC 45 PCM synchrony PCM_CLK 46 PCM clock SIM808 PCM interface only supports master mode, data length is 16 bits (linear), and PCM clock rate is 256 KHz. Table 21: PCM pin specification Feature specification Line Interface Format Linear(Fixed) Data length 16bits(Fixed) PCM Clock/Sync Source Master Mode(Fixed) PCM Clock Rate 256Khz(Fixed) PCM Sync Format Short sync/Long sync both support Zero Padding/Sign extensi Default Zero Padding on Data Ordering MSB/LSB both support Note: User can use AT command control PCM interface, for details please refer to document [1]. 4.11.1 PCM Multiplex Function With GPIO5 and GPIO6, PCM interface can be configured as SPI or SD interface, the following table shows the detailed multiplex function. Table 22: PCM Multiplex Function Name Pin number Mode 0(default) PCM_OUT 48 PCM_OUT PCM_IN 47 PCM_IN PCM_SYNC 45 PCM_SYNC PCM_CLK 46 PCM_CLK GPIO6 44 GPIO6 GPIO5 43 GPIO5 Note: Multiplex Function need different software version. Mode 1 GPIO10 DISP_DATA DISP_CS GPIO8 DISP_CLK DISP_D/C Mode 2 MC3DA3 MC3DA2 MC3CK MC3CM0 MC3DA1 MC3DA0 Mode 3 / GPIO9 GPIO7 GPIO8 / / SIM808_Hardware Design_V1.00 43 2014.03.27 4.11.2 PCM Interface Refer to the following figure for PCM design: Smart Machine Smart Decision Figure 40: PCM reference circuit 4.11.3 LCD Display/SPI Interface SIM808 provides a serial interface. It could be used as SPI interface in the embedded AT application. For details about embedded AT application, please refer to document [1]. Refer to the following figure for SPI design: DISP_CS DISP_D/C DISP_CLK DISP_DATA GND SPI_CS SPI_D/C SPI_CLK SPI_DATA GND Figure 41: LCD reference circuit 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. SIM808_Hardware Design_V1.00 44 2014.03.27 4.11.4 SD Card Interface Smart Machine Smart Decision MC3DA2 MC3DA3 MC3CM0 VDD_EXT MC3CK VSS MC3DA0 MC3DA1 Module DAT2 DAT3 CMD VDD CLK VSS DAT0 DAT1 SD card Figure 42: SD reference circuit If the VDD of SD card is 2.8V, user can use VDD_EXT power the SD card directly. If the VDD is 3.3V, customer should design the power circuit external. 4.12 Keypad Interface SIM808 consists of 4 keypad column outputs and 4 keypad row inputs, and it can support two kinds of connections, the traditional 4*4 keypad matrix and the extended 4*4*2 keypad matrix. Figure 43: Traditional keypad reference circuit Note:1、 According to the traditional 4*4 keypad matrix, when there are unused COLs or ROWs, user can execute AT command to define unused COLs and ROWs as GPIO, for details please see the document [1]. 2、Press COL0 and ROW0 or pull down COL0 when power-on(PWRKEY, Charging, RTC alarm), power sequence is USB Download. SIM808_Hardware Design_V1.00 45 2014.03.27 Smart Machine Smart Decision Module supports a new keypad connection, it can support 4*4*2 amount 32 keypads, meet full keyboard demand, and the connection diagram is as follow: Figure 44: Extended keypad reference circuit Note: Do not change the 20KΩ resistor in the diagram. Customer should add a resistor to enhance the ESD performance and the value of resistor should be less than 1KΩ, the connection diagram is shown in follow figure as an example. COLx <1K 20K ROWx Figure 45: Enhance the ESD performance of keypad circuit Module can detect two buttons pressed synchronously at both the traditional and extended keypad connection, but customer should notice that, do not assign keys which will be pressed at the same time on same COL and ROW when implement the extended keypad design. The following figure is an example to explain this situation, “CTRL” and “A” can not be recognized if the two buttons were pressed at the same time. SIM808_Hardware Design_V1.00 46 2014.03.27 Smart Machine Smart Decision Figure 46: Keypad detected Table 23: Pin definition of the keypad interface Name Pin COL0 62 COL1 61 COL2 60 COL3 59 ROW0 58 ROW1 57 ROW2 56 ROW3 55 Function Keypad matrix column Keypad matrix row Default state Pull up Pull down Pull down Pull down Pull down Pull down Pull down Pull down Table 24: Keypad multiplex function Pin name COL0 COL1 COL2 COL3 ROW0 ROW1 ROW2 ROW3 Pin number 62 61 60 59 58 57 56 55 Mode 0(default) COL0 COL1 COL2 COL3 ROW0 ROW1 ROW2 ROW3 Mode 1 GPIO18 GPIO17 GPIO16 GPIO15 GPIO14 GPIO13 GPIO12 GPIO11 Note: Multiplex Function need different software version . 4.13 I2C BUS The SIM808 provides an I2C interface, it can be driven by either the master or slave and conform to the I2C specification. It has the following features: z Compliant master mode operation SIM808_Hardware Design_V1.00 47 2014.03.27 z Adjustable clock speed for LS/FS mode operation z Support 7-bit/10-bit addressing z Support high speed mode z Support slave clock extension z START/STOP/REPEATED condition z Manual transfer mode z Multi-write per transfer (up to 8 data bytes for non-DMA mode) z Multi-read per transfer (up to 8 data bytes for non-DMA mode) z Multi-transfer per transaction z Combined format transfer with length change capability Active drive/write-and I/O configuration Table 25: Pin definition of the I2C Pin name SCL SDA Pin number 39 38 Description I2C serial bus clock I2C serial bus data Note: I2C has been pulled up to 2.8V via 4.7KΩ. Table 26: I2C multiplex function Pin name Pin number Mode 0(default) SCL 39 SCL SDA 38 SDA Mode 1 GPIO2 GPIO1 Smart Machine Smart Decision 4.13.1 General Purpose Input/Output (GPIO) SIM808 provides 2 GPIO pins. The output voltage level of the GPIO can be set by the AT command “AT+ SGPIO”. The input voltage level of the GPIO can also be read by the AT command “AT+ SGPIO”. For more details, please refer to document [1]. Table 27: Pin definition of the GPIO Pin name Pin number Reset state GPIO6 44 Pull down GPIO5 43 Pull down 4.14 ADC Table 28: Pin definition of the ADC Pin name ADC1 ADC2 Pin number 23 24 Description Analog to Digital Converter Analog to Digital Converter SIM808 provides two auxiliary ADC, which can be used to measure the voltage. User can use AT command SIM808_Hardware Design_V1.00 48 2014.03.27 Smart Machine Smart Decision “AT+CADC” to read the voltage value. For details of this AT command, please refer to document [1]. Table 29: ADC specification Parameter Min Typ Voltage range 0 - ADC Resolution - 10 Sampling rate - - ADC precision 10 Note: the voltage should less than 2.8V, or the ADC may be damaged. Max 2.8 1.0833 20 Unit V bits MHz mV 4.15 PWM Table 30: Pin definition of the PWM Pin name PWM1 PWM2 Pin number 42 41 Description PWM1, multiplex with GPIO4 PWM2, multiplex with GPIO3 Note: SIM808 can only support 1 PWM synchronously, if customer set PIN 42 as PWM, so PIN41 can only be used as GPIO. PWM output frequency varies from 0 to 2KHz.Two 7-bit unsigned binary parameters are used for the output period and for the duty cycle. The AT command “AT + SPWM” is used to set the output period and duty cycle of the PWM. For details, please refer to document [1]. A typical circuit of the PWM drives buzzer is shown in the following figure: VBAT 4.7K PWM 47K Figure 47: Reference circuit of PWM drive buzzer Table 31: Buzzer output characteristics Parameter Min Typ Max Unit Working voltage 2.5 2.8 2.9 V Working current 16 mA Note: PWM pin must keep low when module in the boot process. Table 32: PWM multiplex function SIM808_Hardware Design_V1.00 49 2014.03.27 Pin name PWM1 PWM2 Pin number 42 41 Mode 0(default) PWM1 GPIO3 Smart Machine Smart Decision Mode 1 GPIO4 PWM2 4.16 Network Status Indication Table 33: Pin definition of the NETLIGHT Pin name NETLIGHT Pin number 50 Description 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 34: Status of the NETLIGHT pin Status Off 64ms On/ 800ms Off 64ms On/ 3000ms Off 64ms On/ 300ms Off SIM808 behavior SIM808 is not running SIM808 not registered the network SIM808 registered to the network PPP GPRS communication is established A reference circuit is recommended in the following figure: Figure 48: Reference circuit of NETLIGHT 4.17 Operating Status Indication The STATUS pin indicates the operating status of module. The pin output high when module power on, output is low when module powered off. Table 35: Pin definition of the STATUS Pin name STATUS Pin number 49 Description Operating status indication SIM808_Hardware Design_V1.00 50 2014.03.27 4.18 RF Synchronization Signal Smart Machine Smart Decision The synchronization signal serves to indicate growing power consumption during the transmit burst. Table 36: Definition of the RF_SYNC pin Pin name RF_SYNC Pin number 63 Description Transmit synchronization signal Note: Do not pull up RF_SYNC. The timing of the synchronization signal is shown in the following figure. High level of the RF_SYNC signal indicates increased power consumption during transmission. Figure 49: RF_SYNC signal during transmit burst 4.19 GSM antenna Interface GSM antenna port is named RF_ANT. The impedance should be 50Ω. VSWR should be less than 2. It is recommended that GSM antenna and Bluetooth antenna be placed as far as better to keep the isolations more than 30dB. The customer’s GSM antenna also 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. The following figure is the recommended circuit. Figure 50: GSM antenna matching circuit In this figure, the components R101,R102,C101 and C102 is used for antenna matching, the components’ value SIM808_Hardware Design_V1.00 51 2014.03.27 Smart Machine Smart Decision only can be got after the antenna tuning. Usually, matching components’ value is provided by antenna vendor, the default value of R101 and R102 are 0Ω, and reserve the place of C101 and C102 without soldering. The RF test connector in Figure 50 is used for conducted RF performance test, and should be placed as close as possible to the module’s RF_ANT pad. The traces in bold type should be treated as 50Ω impedance controlled line in PCB layout. For details about radio frequency trace layout, please refer to document [9]. 5 GPS Application Interface SIM808 provide a high-performance L1 GPS solution for cellular handset applications. The solution offers best-in-class acquisition and tracking sensitivity, Time-To-First-Fix (TTFF) and accuracy. The GPS engine supports both fully-autonomous operations for use in handheld consumer navigation devices and other standalone navigation systems. The module supports GPS, QZSS, SBAS ranging (WAAS, EGNOS, GAGAN, MSAS). The GPS NMEA information is output by serial port. The default baud rate is 115200bps. The GPS engine is controlled by GSM engine, so when it is necessary to run GPS,the GSM engine must be powered on and not in SLEEP mode. All the GPS function is controlled by AT command via serial port. The GPS functions of AT commands are listed in the following table. Table 37: AT Commands for GPS function Command Description AT+CGPSPWR GPS power control AT+CGPSRST GPS mode reset (hot/warm/cold) AT+CGPSSTATUS Get current GPS status AT+CGPSOUT GPS NMEA data output control AT+CGPSINF Get current GPS location info AT+CGPSIPR Set GPS NMEA output UART bps For details of these AT command, please refer to document [1]. 5.1 GPS Operating Modes GPS has two operating modes which can be controlled by AT command. Active mode: GPS is active as a GPS receiver. The GPS engine will automatically acquire and track GPS satellites. Power down mode: The GPS engine will be set into this mode by sending AT command “AT+CGPSPWR=0”. In this mode the internal power supply for GPS will be shutdown, and the current consumption is very low. The last position, current time and ephemeris data will be stored in the GSM host memory. SIM808_Hardware Design_V1.00 52 2014.03.27 5.2 GPS Power on/down Scenarios Smart Machine Smart Decision 5.2.1 Power on GPS engine User can power on GPS engine by sending AT command “AT+CGPSPWR=1”. 5.2.2 Power down GPS engine User can power down GPS engine by sending AT command “AT+CGPSPWR=0”. 5.3 GPS Antenna Interface 5.3.1 GPS Antenna Interface The customer’s GPS antenna also can be located in the customer’s main board and connect to module’s GPS_ANT pad through microstrip line or other type RF trace which impendence must be 50Ω. Figure 51: GPS antenna matching circuit In Figure 51, 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. 5.3.2 GPS Antenna Choice Consideration To obtain excellent GPS reception performance, a good antenna will always be required. The antenna is the most critical item for successful GPS reception in a weak signal environment. Proper choice and placement of the antenna will ensure that satellites at all elevations can be seen, and therefore, accurate fix measurements are obtained. Most customers contract with antenna design houses to properly measure the radiation pattern of the final mounted configuration in a plastic housing with associated components near the antenna. Linear antennas are becoming more popular, and the gain is reasonable, since a smaller ground plane can be used. User can consider following factors as: z Choose a linear antenna with a reasonably uniform hemispherical gain pattern of >-4dBi. z Use of an antenna with lower gain then this will give less than desirable results. Please note that a RHCP antenna with a gain of 3dBi, equates to a linear polarized antenna of 0dBi. SIM808_Hardware Design_V1.00 53 2014.03.27 Smart Machine Smart Decision z Proper ground plane sizing is a critical consideration for small GPS antennas. z Proper placement of the GPS antenna should always be the FIRST consideration in integrating the SIM808 GPS Module. If the customer’s design will allow for a ceramic RHCP patch antenna with an appropriately sized ground plane, and the patch is normally oriented towards the sky, then that particular solution usually works the best. Note that if the patch antenna ground plane is less than 60x60mm, then compromises to the beam width and gain pattern could result. Usually the gain becomes very directional, and looses several dB of performance. Since results can vary, measuring the antenna radiation pattern in the final housing in an appropriate anechoic chamber is required. Some customers do not have the size availability to implement a patch antenna approach. In that instance, use of a Linear Polarized (LP) antenna is the next best alternative. There are new ceramic LP antennas on the market that exhibit reasonable gain characteristics once properly mounted in the housing, and when matched to an appropriate sized ground. Generally the ground plane requirements are smaller for a LP antenna when compared to a patch, but once again, proper testing in an 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. Use of PIFA antenna is another LP possibility, but the PIFA usually exhibits a considerable amount of gain nulls, or “holes” in the radiation pattern. This will be undesirable for obtaining a low circular error probability (CEP), since the antenna may not allow the receiver to capture the desired satellite at the ideal orientation due to these noted gain nulls. Once again, careful testing in an appropriate anechoic chamber is required. If the customer’s design is for automotive applications, then an active antenna can be used and located on top of the car in order to achieve the best signal quality. GPS antenna choice should be based on the designing product and other conditions. For detailed Antenna designing consideration, please refer to related antenna vendor’s design recommendation. The antenna vendor will offer further technical support and tune their antenna characteristic to achieve successful GPS reception performance depending on the customer’s design. 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 SIM808. Table 38: Absolute maximum ratings Symbol Min SIM808_Hardware Design_V1.00 Typ 54 Max Unit 2014.03.27 Smart Machine Smart Decision VBAT - - 4.5 V Peak Current 0 - 2.0 A VBUS - - 30 V II* - - 8 mA IO* - - 8 mA * These parameters are for digital interface pins, such as keypad, GPIO, I2C, UART, LCD and PCM.. 6.2 Recommended Operating Conditions Table 39: Recommended operating conditions Symbol VBAT TOPER TSTG Parameter Power supply voltage Operating temperature Storage temperature Min Typ Max Unit 3.4 4.0 4.4 V -40 +25 +85 ℃ -45 +90 ℃ 6.3 Digital Interface Characteristics Table 40: 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 keypad, GPIO, I2C, UART, LCD, PWMs and DEBUG. Unit uA uA V V V V 6.4 SIM Card Interface Characteristics Table 41: SIM card interface characteristics Symbol Parameter Min Typ IIH High-level input current -1 - IIL Low-level input current -1 - 1.4 - VIH High-level input voltage 2.4 - - - VIL Low-level input voltage 1.62 - VOH High-level output voltage 2.7 - SIM808_Hardware Design_V1.00 55 Max 1 1 0.27 0.4 - Unit uA uA V V V V V V 2014.03.27 Smart Machine Smart Decision - - 0.36 V VOL Low-level output voltage - - 0.4 V 6.5 SIM_VDD Characteristics Table 42: SIM_VDD characteristics Symbol Parameter Output voltage VO IO Output voltage Min Typ Max Unit - 3 - V - 1.80 - - - 10 mA 6.6 VDD_EXT Characteristics Table 43: VDD_EXT characteristics Symbol VO IO Parameter Output voltage Output current Min Typ Max Unit 2.70 2.80 2.95 V - - 50 mA 6.7 VRTC Characteristics Table 44: 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 - 2.8 - V - 3 - uA - 2.8 - V - 2 uA 6.8 Current Consumption (VBAT = 4V, GPS engine is powered down) Table 45: GSM current consumption* Symbol Parameter VBAT Voltage Power drop Voltage ripple Conditions PCL=5 PCL=5 @ f<200kHz @ f>200kHz SIM808_Hardware Design_V1.00 56 Min Typ Max Unit 3.4 4.0 4.4 V 350 mV 50 mV 2 mV 2014.03.27 IVBAT Average current IMAX Peak current Power down mode Sleep mode (AT+CFUN=1): ( BS-PA-MFRMS=9 ) ( BS-PA-MFRMS=5) ( BS-PA-MFRMS=2) Idle mode (AT+CFUN=1): EGSM900 Voice call (PCL=5): GSM850 EGSM900 DCS1800 PCS1900 Data mode GPRS (1Rx,4Tx): GSM850 EGSM900 DCS1800 PCS1900 Data mode GPRS (3Rx,2Tx): GSM850 EGSM900 DCS1800 PCS1900 Data mode GPRS (4Rx,1Tx): GSM850 EGSM900 DCS1800 PCS1900 During TX burst Smart Machine Smart Decision 38 50 uA 1.965 mA 1.7 mA 1.4 mA 22.1 mA 207.63 mA 202.32 mA 139.825 137.805 445.82 mA 424.32 mA 293.62 279.18 329.79 mA 220.62 mA 223.18 218.34 221.25 mA 220.62 mA 158.01 158.62 2.0 A * In above table the current consumption value is the typical one of the module tested in laboratory. In the mass production stage, there may be differences among each individual. 6.9 Electro-Static Discharge SIM808 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 46: The ESD characteristics (Temperature: 25℃, Humidity: 45 %) Pin VBAT GND RXD, TXD Antenna port Contact discharge ±5KV ±5KV ±4KV ±5KV Air discharge ±10KV ±10KV ±8KV ±10KV SIM808_Hardware Design_V1.00 57 2014.03.27 SPK1P/ SPK1N MIC1P/ MIC1N PWRKEY ±4KV ±4KV Smart Machine Smart Decision ±8KV ±8KV Note: It is suggested that customers in serials with 100ohm resistances on UART lines for ESD consideration. 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 47: SIM808 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 Table 48: SIM808 DCS 1800 and PCS 1900 conducted RF output power PCL DCS 1800 and PCS 1900 Nominal output power (dBm) Tolerance (dB) for conditions Normal Extreme SIM808_Hardware Design_V1.00 58 2014.03.27 29 36 30 34 31 32 0 30 1 28 2 26 3 24 4 22 5 20 6 18 7 16 8 14 9 12 10 10 11 8 12 6 13 4 14 2 15-28 0 Smart Machine Smart Decision ±2 ±2.5 ±3 ±4 ±3 ±4 ±3 ±4 ±3 ±4 ±3 ±4 ±3 ±4 ±3 ±4 ±3 ±4 ±3 ±4 ±3 ±4 ±3 ±4 ±4 ±5 ±4 ±5 ±4 ±5 ±4 ±5 ±4 ±5 ±5 ±6 ±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. 6.10.2 Module RF Receive Sensitivity The following table shows the module’s conducted receive sensitivity, it is tested under static condition. Table 49: SIM808 conducted RF receive sensitivity Frequency GSM850 EGSM900 DCS1800 PCS1900 Receive sensitivity(Typical) -109dBm -109dBm -109dBm -109dBm Receive sensitivity(Max) -107dBm -107dBm -107dBm -107dBm SIM808_Hardware Design_V1.00 59 2014.03.27 6.10.3 Module Operating Frequencies Smart Machine Smart Decision The following table shows the module’s operating frequency range; it is followed by the 3GPP TS 05.05 technical specification requirement. Table 50: SIM808 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 SIM808_Hardware Design_V1.00 60 2014.03.27 7 Manufacturing 7.1 Top and Bottom View of SIM808 Smart Machine Smart Decision Figure 52: Top and Bottom View of SIM808 7.2 Typical Solder Reflow Profile Figure 53: Typical Solder Reflow Profile Note: Please refer to《Module secondary-SMT-UGD》 for more information about the module shipping and manufacturing. SIM808_Hardware Design_V1.00 61 2014.03.27 7.3 The Moisture Sensitivity Level Smart Machine Smart Decision The moisture sensitivity level of SIM808 is 3. The module should be mounted within 168 hours after unpacking in the environmental conditions of temperature <30°C and relative humidity of <60% (RH). It is necessary to bake the module if the above conditions are not met: Table 51: Moisture classification level and floor life Level Floor Life (out of bag) at factory ambient≤30°C /60% RH or as stated 1 Unlimited at ≤30°C /85% RH 2 1 year 2a 4 weeks 3 168 hours 4 72 hours 5 48 hours 5a 24 hours 6 Mandatory bake before use. After bake, it must be reflowed within the time limit specified on the label. NOTES: 1. If the vacuum package is not open for 6 months or longer than the packing date, baking is also recommended before re-flow soldering. 2. For product handling, storage, processing, IPC / JEDEC J-STD-033 must be followed. 7.4 Baking Requirements Because of its sensitivity to moisture absorption, SIM808 should be baked sufficiently before re-flow soldering. Otherwise SIM808 will be at the risk of permanent damage during re-flow soldering. SIM808 should be baked 192 hours at temperature 40°C +5°C /-0°C and <5% RH for low-temperature device containers, or 72 hours at temperature 80°C±5°C for high-temperature device containers. Care should be taken that the plastic tray is not heat resistant, SIM808 modules should be taken out for baking, and otherwise the tray may be damaged by high-temperature during baking. Table 52: Baking requirements Baking temperature 40°C±5°C 120°C±5°C Moisture <5% <5% Time 192 hours 4 hours SIM808_Hardware Design_V1.00 62 2014.03.27 Appendix Smart Machine Smart Decision A. Related Documents Table 53: Related documents SN Document name Remark [1] SIM800_AT Command SIM800 AT Command Manual Manual [2] AN_SIM900_TCPIP TCP/IP Applications User Manual [3] SIM900_Multiplexer User SIM808 Multiplexer User Manual Application Note Manual_Application Note [4] AN_SIM900 SIM808 Series Update Tool User Guide Series_Update Tool_UGD [5] AN_SIM900_AUDIO Applications Note About SIM808 Audio [6] AN_SIM900_Audio LINE-IN input Applications Note About SIM808 LINE-IN Input [7] SIM900_Embedded AT SIM808 Embedded AT Application Note Application Note [8] AN_Serial Port Application Note About Serial Port [9] AN_SIM900-TE PCB Application Note About SIM808-TE PCB Layout & Schematic Layout & Schematic for Reference [10] Module secondary-SMT-UGD Module secondary SMT User Guide [11] ITU-T Draft new Serial asynchronous automatic dialing and control recommendation V.25ter: [12] GSM 07.07: Digital cellular telecommunications (Phase 2+); AT command set for GSM Mobile Equipment (ME) [13] GSM 07.10: Support GSM 07.10 multiplexing protocol [14] 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) [15] 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 [16] GSM 11.11: Digital cellular telecommunications system (Phase 2+); Specification of the Subscriber Identity Module – Mobile Equipment (SIM – ME) interface [17] GSM 03.38: [18] 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 SIM808_Hardware Design_V1.00 63 2014.03.27 B. Terms and Abbreviations Smart Machine Smart Decision Table 54: Terms and Abbreviations Abbreviation ADC AMR CS CSD CTS CEP DTE DTR DTX EFR EGSM EGNOS ESD ETS FR GPRS GSM GPS GAGAN HR IMEI Li-ion MO MS MT MSAS NMEA PAP PBCCH PCB PCL PCS PDU PPP QZSS RF RMS Description Analog-to-Digital Converter Adaptive Multi-Rate Coding Scheme Circuit Switched Data Clear to Send Circular Error Probable Data Terminal Equipment (typically computer, terminal, printer) Data Terminal Ready Discontinuous Transmission Enhanced Full Rate Enhanced GSM European Geostationary Navigation Overlay Service Electrostatic Discharge European Telecommunication Standard Full Rate General Packet Radio Service Global Standard for Mobile Communications Global Positioning System The GPS Aided Geo Augmented Navigation Half Rate International Mobile Equipment Identity Lithium-Ion Mobile Originated Mobile Station (GSM engine), also referred to as TE Mobile Terminated Multi-Functional Satellite Augmentation System National Marine Electronics Association 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 Quasi-Zenith Satellites System Radio Frequency Root Mean Square (value) SIM808_Hardware Design_V1.00 64 2014.03.27 RTC RX SIM SBAS SMS TE TX UART URC USSD WAAS Phonebook abbreviations FD LD MC ON RC SM NC Real Time Clock Receive Direction Subscriber Identification Module Satellite Based Augmentation Systems Short Message Service Terminal Equipment, also referred to as DTE Transmit Direction Universal Asynchronous Receiver & Transmitter Unsolicited Result Code Unstructured Supplementary Service Data Wide Area Augmentation System 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 55: 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. SIM808_Hardware Design_V1.00 65 2014.03.27 Smart Machine Smart Decision 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. SIM808_Hardware Design_V1.00 66 2014.03.27 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 SIM808_Hardware Design_V1.00 67 2014.03.27

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