Sim Card Design Consideration; Design Considerations For Sim Card Holder - SimCom SIM800 Hardware Design

6-pin SIM card holder is illustrated in the following figure.
VSIM
SIM_RST
SIM_CLK
SIM_PRE
Module
SIM_DATA
4.9.2.

SIM Card Design Consideration

SIM card circuit is susceptible to interference, causing the SIM card failures or some other situations, so it is
strongly recommended to follow these guidelines while designing:

Make sure that SIM card holder should far away from GSM antenna while in PCB layout.

SIM traces should keep away from RF lines, VBAT and high-speed signal lines.

The traces should be as short as possible.

Keep SIM holder's GND connect to main ground directly.

Shielding the SIM card signal by ground well.

Recommended to place a 1uF capacitor on SIM_VDD line and keep close to the holder.

Add some TVS and the parasitic capacitance should not exceed 50pF, and 51Ω resistor in serials the
SIM signal could enhance ESD protection.
4.9.3.

Design Considerations for SIM Card Holder

For 8 pins SIM card holder, SIMCom recommends to use Molex 91228.User can visit
for more information about the holder.
SIM800_Hardware Design_V1.10
Figure 33: Reference circuit of the 6-pin SIM card holder
38
51R
51R
51R
1uF
Smart Machine Smart Decision
SIM Card
GND
VCC
VPP
RST
CLK I/O
C707 10M006 512 2
SMF12C
http://www.molex.com
2018-08-13