hardware design v2.00
Table Of Contents
- Contents
- Version History
- 1 Introduction
- 2 SIM908 Overview
- 3 Package Information
- 4 GSM Application Interface
- 4.1 Power Supply
- 4.2 Power on/down Scenarios
- 4.3 Power Saving Mode
- 4.4 Charging Interface
- 4.5 RTC Backup
- 4.6 Serial Interfaces
- 4.7 Audio Interfaces
- 4.8 SIM Card Interface
- 4.9 LCD Display/SPI Interface
- 4.10 Keypad Interface
- 4.11 ADC
- 4.12 RI Behaviors
- 4.13 Network Status Indication
- 4.14 General Purpose Input/Output (GPIO)
- 4.15 PWM
- 4.16 I2C Bus
- 4.17 GSM Antenna Interface
- 5 GPS Application Interface
- 6 Electrical, Reliability and Radio Characteristics
- 6.1 Absolute Maximum Ratings
- 6.2 Recommended Operating Conditions
- 6.3 Digital Interface Characteristics
- 6.4 SIM Card Interface Characteristics
- 6.5 VDD_EXT Characteristics
- 6.6 SIM_VDD Characteristics
- 6.7 VRTC Characteristics
- 6.8 Current Consumption (VBAT = 3.8V, GPS engine is powered down)
- 6.9 Electro-Static Discharge
- 6.10 Radio Characteristics
- 6.11 Module label information
- Appendix
Smart Machine Smart Decision
SIM908_Hardware Design_V2.00 2012.05.07
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1 Introduction
This document describes SIM908 hardware interface in great detail.
This document can help user to quickly understand SIM908 interface specifications, electrical and mechanical
details. With the help of this document and other SIM908 application notes, user guide, users can use SIM908 to
design various applications quickly.
2 SIM908 Overview
Designed for global market, SIM908 is integrated with a high performance GSM/GPRS engine and a GPS 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. SIM908 features GPRS multi-slot class 10/ class 8 (optional) and
supports the GPRS coding schemes CS-1, CS-2, CS-3 and CS-4. The GPS solution offers best- in-class
acquisition and tracing sensitivity, Time-To-First-Fix (TTFF) and accuracy.
With a tiny configuration of 30*30*3.2mm, SIM908 can meet almost all the space requirements in user
applications, such as M2M, smart phone, PDA, tracker and other mobile devices.
SIM908 has 80 SMT pads, and provides all hardware interfaces between the module and customers’ boards.
z Serial port and debug port can help user easily develop user’s applications.
z GPS Serial port.
z Two audio channels include two audio inputs and two audio outputs. These can be easily configured by AT
command.
z Charging interface.
z Programmable general purpose input and output.
z The keypad and SPI display interfaces will give users the flexibility to develop customized applications.
z RF pad and connector interface.
SIM908 is designed with power saving technique so that the current consumption is as low as 1.2mA in sleep
mode (GPS engine is powered down).
SIM908 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 SIM908 Key Features
Table 1: SIM908 GSM/GPRS engine key features
Feature Implementation
Power supply 3.2V ~ 4.8V
Power saving
Typical power consumption in sleep mode is 1.2mA ( BS-PA-MFRMS=9, GPS
engine is powered down )
Charging Supports charging control for Li-Ion battery
Frequency bands
z SIM908 Quad-band: GSM 850, EGSM 900, DCS 1800, PCS 1900. SIM908
can search the 4 frequency bands automatically. The frequency bands also
can be set by AT command “AT+CBAND”. For details, please refer to