Figure 1: Sim900D Functional Diagram - SimCom SIM900D Hardware Design

Smart Machine Smart Decision
GPIO Battery ANT
Serial Port
Serial RF
Battery
GPIO
Interface interface
interface
Debug/upgrading
program
RF
I/Q
Transceiver
Power Amplifier
COL
Analog
Controller
With PMU
32.768KHz
RTC
SIM interface
Digital Baseband
LCD interface
26MHz
Flash+SRAM
PWRKEY
Analog interface
RTC
Audio interface ADC Charger

Figure 1: SIM900D functional diagram

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SIM900D_Hardware Design_V2.02 2012-05-07