Data Sheet

Smart Machine Smart Decision
SIM800F_Hardware Design_V1.00 38 2015-07-31
4.9.2 SIM Card Circuit Design Guide
SIM card signal could be interfered by the high speed signal, it is 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
 Parasitic capacitance of TVS on SIM_CLK/SIM_DATA should less than 50pF
4.9.3 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.
Figure 34: Molex 91228 SIM card holder
Table 16: Pin description (Molex SIM card holder)
Pin name Signal Description
C1 SIM_VDD SIM card power supply