SIM900D Hardware Design
2 SIM900D Overview
Designed for global market, SIM900D is a quad-band GSM/GPRS engine that works on frequencies GSM
850MHz, EGSM 900MHz, DCS 1800MHz and PCS 1900MHz. SIM900D features GPRS multi-slot class 10/
class 8 (optional) and supports the GPRS coding schemes CS-1, CS-2, CS-3 and CS-4.
With a tiny configuration of 33mm x 33mm x 3mm, SIM900D can meet almost all the space requirements in your
applications, such as M2M, smart phone, PDA, FWP, and other mobile device.
The physical interface to the mobile application is a 48-pin SMT pad, which provides all hardware interfaces
between the module and customers’ boards.
The hardware package of 48 pins
z
9 GND pins and 2 VBAT pins
z
2 pins are programmable as General Purpose I/O .This gives you the flexibility to develop customized
applications.
z
Serial port and Debug port can develop your applications easily.
z
Two audio channels include two microphone inputs and two speakers’ outputs. This can be easily configured
by AT command.
With the charge circuit integrated inside the SIM900D, it is very suitable for the battery power application.
The SIM900D provides RF antenna interface. And customer’s antenna should be located in the customer’s main
board and connect to module’s antenna pad through micro strip line or other type RF traces whose impendence
must be controlled in 50
Ω
.
The SIM900D is designed with power saving technique so that the current consumption is as low as 1.2mA in
SLEEP mode.
The SIM900D is integrated with the TCP/IP protocol; extended TCP/IP AT commands are developed for
customers to use the TCP/IP protocol easily, which is very useful for those data transfer applications.
The modules are fully RoHS compliant to EU regulation.
2.1 SIM900D Key Features
Table3: SIM900D key features
Feature
Implementation
Power supply
Single supply voltage 3.4V – 4.5V
Power saving
Typical power consumption in SLEEP mode is 1.5mA ( BS-PA-MFRMS=2 )
SIM900D_HD_V1.02
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