Sim Card Interface; Sim Card Application - SIM Tech SIMCom SIM800H Hardware Design

will be some cheep noise from speaker output easily. So it is better to put big capacitors and ferrite beads near
audio PA input.
TDD noise has something to do with GND signal. If GND plane is not good, lots of high-frequency noises will
interference microphone and speaker over bypass capacitor. So a good GND during PCB layout could avoid
TDD noise.

4.8. 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.
4.8.1.

SIM Card Application

Table 17: SIM pin definition
Pin name Pin number
SIM_VDD 16
SIM_DATA 14
SIM_CLK 55
SIM_RST 15
SIM_DET 54
It is recommended to use an ESD protection component such as ST
SEMI (www.onsemi.com
The reference circuit of the 8-pin SIM card holder is illustrated in the following figure.
Module
The SIM_DET pin is used for detection of the SIM card hot plug in. Customer 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, customer can keep the SIM_DET pin open. The reference circuit
of 6-pin SIM card holder is illustrated in the following figure.
SIM800H _Hardware Design_V2.03
Function
Voltage supply for SIM card. Support 1.8V or 3V SIM card
SIM data input/output
SIM clock
SIM reset
SIM card detection
) SMF05C. That the SIM peripheral circuit should be close to the SIM card socket.
4.7K
VDD_EXT
SIM_VDD
SIM_RST
SIM_CLK
SIM_DET
SIM_DATA
22pF
Figure 32: Reference circuit of the 8-pin SIM card holder
(www.st.com
VCC
51Ω
RST
51Ω
CLK
PRESENCE
51Ω
100nF
ESDA6V1
36
Smart Machine Smart Decision
) ESDA6V1-5W6 or ON
MOLEX-91228
GND
VPP
I/O
GND
SIM Card
2016-10-10