User Manual

GSM/GPRS Module Series
GC10 Hardware Design
GC10_Hardware_Design Confidential / Released 49 / 76
The reference circuit for a 6-pin SIM card socket is illustrated as the following figure:
Figure 33: Reference Circuit for 6-pin SIM Card Holder
In order to enhance the reliability and availability of the SIM card in application. Please follow the criteria
below in the SIM circuit design.
 Keep layout of SIM card as close as possible to the module. Assure the possibility of the length of the
trace is less than 100mm.
 Keep SIM card signal away from RF and VBAT alignment.
 Assure the ground between module and SIM cassette short and wide. Keep the width of ground no
less than 0.5mm to maintain the same electric potential. The decouple capacitor of SIM_VDD is less
than 1uF and must be near to SIM cassette.
 To avoid cross talk between SIM_DATA and SIM_CLK. Keep them away with each other and shield
them with surrounded ground.
 In order to offer good ESD protection, it is recommended to add TVS such as WILL
(http://www.willsemi.com/) ESDA6V8AV6. The 22Ω resistors should be connected in series between
the module and the SIM card so as to suppress the EMI spurious transmission and enhance the ESD
protection. Please to be noted that the SIM peripheral circuit should be close to the SIM card socket.
 Place the RF bypass capacitors (33pF) close to the SIM card on all signals line for improving EMI.
3.9.2. SIM Cassette
As to the 6-pin SIM card holder, it is recommended to use Amphenol C707 10M006 512 2. Please visit
http://www.amphenol.com for more information.