SIM900 Hardware Design
Pin Name Signal Description
C1
SIM_VDD SIM Card Power supply, it can identify automatically the SIM Card power
mode,one is 3.0V±10%, another is 1.8V±10%. Current is about 10mA.
C2
SIM_RST SIM Card Reset.
C3
SIM_CLK SIM Card Clock.
C5
GND Connect to GND.
C6
VPP Not connect.
C7
SIM_DATA SIM Card data I/O.
For 8 pins SIM card holder, we recommend to use Molex 91228.You can visit http://www.molex.com for more
information about the holder.
Figure 30: Molex 91228 SIM card holder
Table
14: Pin description (Molex SIM card holder)
Pin Name Signal Description
C1
SIM_VDD SIM Card Power supply, it can identify automatically the SIM Card power
mode,one is 3.0V±10%, another is 1.8V±10%. Current is about 10mA.
C2
SIM_RST SIM Card Reset
SIM900_HD_V1.05 06.23.2010
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