Quectel EC21 Mini PCIe Series Hardware Design page 26

Module
GND
USIM_VDD
USIM_RST
USIM_CLK
USIM_PRESENCE
USIM_DATA
Figure 4: 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_PRESENCE unconnected. A
reference circuit for (U)SIM interface with a 6-pin (U)SIM card connector is illustrated in the following
figure.
Module
GND
USIM_VDD
USIM_RST
USIM_CLK
USIM_DATA
Figure 5: 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:
EC21_Mini_PCIe_Hardware_Design
USIM_VDD
15K
0R
0R
0R
33pF 33pF 33pF
USIM_VDD
15K
0R
0R
0R
33pF 33pF 33pF
GND
EC21 Mini PCIe Hardware Design
GND GND
(U)SIM Card Connector
VCC
GND
LTE Standard Module Series
100nF
(U)SIM Card Connector
VCC GND
RST VPP
IO
CLK
GND
100nF
GND
RST VPP
CLK IO
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