Quectel UG89 Hardware Design page 37

Module
Figure 15: Reference Circuit of (U)SIM Interface with an 8-pin (U)SIM Card Connector
If (U)SIM card detection function is not needed, please keep USIM_DET unconnected. A reference circuit
for (U)SIM interface with a 6-pin (U)SIM card connector is illustrated in the following figure.
Module
Figure 16: Reference Circuit of (U)SIM Interface with a 6-pin (U)SIM Card Connector
In order to enhance the reliability and availability of the (U)SIM card in customers' applications, please
follow the criteria below in (U)SIM circuit design:

Keep placement of (U)SIM card connector as close to the module as possible. Keep the trace length
less than 200mm as far as possible.

Keep (U)SIM card signals away from RF and VBAT traces.

Assure the ground between the module and the (U)SIM card connector short and wide. Keep the trace
width of ground and USIM_VDD no less than 0.5mm to maintain the same electric potential. If the
ground is complete on customers' PCB, USIM_GND can be connected to PCB ground directly.

To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and shield
them with the surrounded ground.
UG89_Hardware_Design
VDD_EXT USIM_VDD
51K
USIM_GND
USIM_VDD
0R
USIM_RST
USIM_CLK
USIM_DET
0R
USIM_DATA 0R
33pF
USIM_VDD
15K
USIM_GND
USIM_VDD
0R
USIM_RST
USIM_CLK
0R
0R
USIM_DATA
33pF 33pF 33pF
15K
100nF
33pF 33pF
GND GND
100nF
(U)SIM Card Connector
VCC
RST
CLK
GND GND
UMTS/HSPA+ Module Series
UG89 Hardware Design
(U)SIM Card Connector
VCC GND
RST VPP
IO
CLK
GND
GND
VPP
IO
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