Smart Machine Smart Decision 
SIM7020_Hardware_Design_V1.02    25       2018-07-25 
MODULE
TVS
SIM
_ VDD
SIM
_ CLK
SIM
_ DATA
SIM_ RST
VCC       GND
RST       VPP
CLK       I
/
O
22
Ω
100
nF
C 707 10M 006 512
SIM Socket
22
Ω
22
Ω
22pF
22
pF
22pF
SIM_ DET
 
Figure 17: SIM interface reference circuit 
 
Note: SIM_DATA has been pulled up with a 10KΩ resistor to SIM_VDD in module. A 100nF 
capacitor on SIM_VDD is used to reduce interference. For more details of AT commands about 
SIM, please refer to document [1].SIM_CLK is very important signal, the rise time and fall time of 
SIM_CLK should be less than 40ns, otherwise the SIM card might not be initialized correctly. If 
SIM_DET is used, a 10KΩ resistor is necessary to pulling up to the power VDD_EXT.     
3.7.2  Recommended SIM Card Holder 
It is recommended to use the 6-pin SIM socket such as C707 10M006 512 produced by Amphenol. 
User can visit http://www.amphenol.com
 for more information about the holder. 
 
Figure 18: Amphenol SIM card socket