Data Sheet

Smart Machine Smart Decision
SIM800F_Hardware Design_V1.00 37 2015-07-31
Table 15: SIM pin definition
Pin name Pin number Function
SIM_VDD 18 Voltage supply for SIM card. Support 1.8V or 3V SIM card
SIM_DATA 15 SIM data input/output
SIM_CLK 16 SIM clock
SIM_RST 17 SIM reset
SIM_DET 14 SIM card detection
The SIM_DET pin is used for SIM card detection. Users can select the 8-pin SIM card holder to implement this
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]
.
It is recommended to place an ESD protection component close to the SIM card holder, such as SMF15C
provided by ON SEMI (www.onsemi.com
). The reference circuit of the 8-pin SIM card holder is illustrated as
below:
Figure 32: Reference circuit of the 8-pin SIM card holder
If the SIM card detection function is not used, users can keep SIM_DET pin open. The reference circuit of 6-pin
SIM card holder is illustrated as below:
Figure 33: Reference circuit of the 6-pin SIM card holder
Note: 51Ω series resistors are not needed for SIM_RST/SIM_CLK/SIM_DATA, which are build-in already.