Neo_M660A GPRS Module Hardware User Guide
Copyright © Neoway Technology Co., Ltd
21
Figure 3-18
Reference design of SIM card interface
20 Ω
20 Ω
20 Ω
1 uF
SIM_DATA
SIM_CLK
SIM_RST
VSIM
GPRS Module
CLK
RST
VCC
GND
SIM Card
DATA
VPP
ESD protectors, such as ESD diodes (lower than 33 pF) or ESD varistors, are recommended on the SIM
signals, especially in automotive electronics or other applications with badly ESD. In other applications,
replace ESD diodes with 27 pF to 33 pF grounding capacitors. The ESD diodes or small capacitors should
be close to the SIM card pin on the socket.
If you use 6-pin SIM card sockets, MCP-C713(H2.8) is recommended. Figure 3-19 shows its
encapsulation.
Figure 3-19
Reference of SIM card socket