Smart Machine Smart Decision
SIM800_Hardware Design_V1.10
37
2018-08-13
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
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.
Module
SMF12C
VSIM
SIM_CLK
SIM_DATA
SIM_RST
SIM_PRE
PRESENCE
51R
1uF
MOLEX
-
91228
SIM
Card
2
2
P
F
4.7K
VDD_EXT
VCC
GND
RST
VPP
CLK
I/O
GND
51R
51R
2
2
P
F
2
2
P
F
Figure 32: Reference circuit of the 8-pin SIM card holder
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
Name
Pin
function
SIM_VDD
30
Voltage supply for SIM card. Support 1.8V or 3V SIM card
SIM_DATA
31
SIM data input/output
SIM_CLK
32
SIM clock
SIM_RST
33
SIM reset
SIM_DET
34
SIM card detection
