Sim Card Design Guide; Design Considerations For Sim Card Holder - SimCom SIM800L Hardware Design

Module
4.8.2.

SIM Card Design Guide

SIM card signal could be interferenced by some high frequency signal, it is strongly recommended to follow
these guidelines while designing:
SIM card holder should be far away from GSM antenna

SIM traces should keep away from RF lines, VBAT and high-speed signal lines

The traces should be as short as possible

Keep SIM card holder's GND connect to main ground directly

Shielding the SIM card signal by ground well

Recommended to place a 100nF capacitor on SIM_VDD line and keep close to the SIM card holder

Add some TVS which parasitic capacitance should not exceed 50pF

Add 51Ω resistor to (SIM_RST/SIM_CLK/SIM_DATA) signal could enhance ESD protection

4.8.3.

Design Considerations for SIM Card Holder

For 8 pins SIM card holder, SIMCom recommends to use Molex 91228.Customer can visit
http://www.molex.com for more information about the holder.
SIM800L(MT6261)_Hardware Design_V1.01
SIM_VDD
SIM_RST
SIM_CLK
SIM_DET
SIM_DATA
22pF
Figure 33: Reference circuit of the 6-pin SIM card holder
VCC
51Ω
RST
51Ω
C707 10M 006 512 2
51Ω
ESDA6V1
100nF
37
Smart Machine Smart Decision
SIM Card
GND
VPP
I/O
CLK
2016-07-07