Quectel QuecOpen AG521R-NA Hardware Design page 50

Module
Figure 18: Reference Circuit of (U)SIM Interface with an 8-Pin (U)SIM Card Connector
If (U)SIM card detection function is not needed, keep USIM_DET disconnected.
A reference circuit for (U)SIM interface with a 6-pin (U)SIM card connector is illustrated in the following figure.
Module
Figure 19: Reference Circuit of (U)SIM Interface with a 6-Pin (U)SIM Card Connector
To enhance the reliability and availability of the (U)SIM card, follow the criteria below in the (U)SIM circuit
design:
⚫
Keep the placement of (U)SIM card connector as close to the module as possible. Keep the trace length as less
than 200 mm as possible.
⚫
Keep (U)SIM card signals away from RF and VBAT traces.
⚫
Assure the trace between the ground of the module and that of the (U)SIM card connector short and wide.
Keep the trace width of ground and USIM_VDD no less than 0.5 mm to maintain the same electric potential.
⚫
To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and shield them
AG521R-NA_QuecOpen_Hardware_Design
VDD_EXT USIM_VDD
470K
USIM_VDD
22R
USIM_RST
USIM_CLK
USIM_DET
22R
USIM_DATA
22R
USIM_VDD
10K
USIM_VDD
22R
USIM_RST
USIM_CLK
22R
22R
USIM_DATA
33 pF
AG521R-NA QuecOpen Hardware Design
10K
100 nF
33 pF 33 pF33 pF
GND
100 nF
33 pF 33 pF
GND
Automotive Module Series
(U)SIM Card Connector
VCC GND
RST VPP
IO
CLK
CD1 CD2
GND
(U)SIM Card Connector
VCC GND
RST VPP
CLK IO
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