Sim Card Interface; Sim Card Application - SimCom SIM800 Hardware Design


Support sniff mode

Supports PCM interface and built-in programmable transcoders for liner voice with transmission

4.9. SIM Card Interface

The SIM interface complies with the GSM Phase 1 specification and the new GSM Phase 2+ specification for
FAST 64 kbps SIM card. Both 1.8V and 3.0V SIM card are supported. The SIM interface is powered from an
internal regulator in the module.
4.9.1.

SIM Card Application

Table 15: SIM pin definition
Name Pin
SIM_VDD 30
SIM_DATA 31
SIM_CLK 32
SIM_RST 33
SIM_DET 34
It is recommended to use an ESD protection component such as ON SEMI
The SIM peripheral circuit should be close to the SIM card socket. The reference circuit of the 8-pin SIM card
holder is illustrated in the following figure.
VDD_EXT
VSIM
SIM_RST
Module
SIM_CLK
SIM_PRE
SIM_DATA
The SIM_DET pin is used for detection of the SIM card hot plug in. User can select the 8-pin SIM card holder
to implement SIM card detection 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].
If the SIM card detection function is not used, user can keep the SIM_DET pin open. The reference circuit of
SIM800_Hardware Design_V1.10
function
Voltage supply for SIM card. Support 1.8V or 3V SIM card
SIM data input/output
SIM clock
SIM reset
SIM card detection
4.7K
Figure 32: Reference circuit of the 8-pin SIM card holder
37
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51R
51R
51R
1uF
Smart Machine Smart Decision
) SMF12CT1G.
MOLEX - 91228
GND
VCC
VPP
RST
CLK I/O
PRESENCE GND
SIM Card
SMF12C
2018-08-13