Quectel UC20 Hardware Design page 42

USIM_CLK
USIM_RST
USIM_PRES
ENCE
USIM_GND
The following figure shows the reference design of the 8-pin USIM card.
Module
NOTE
Some AT commands are invalid when USIM card is not applied.
UC20 supports USIM card hot-plugging via the USIM_PRESENCE pin. For details, refer to document [1]
about the command AT+QSIMDET. If you do not need the USIM card detection function, keep
USIM_PRESENCE unconnected. The reference circuit for using a 6-pin USIM card connector is
illustrated as the following figure.
UC20_Hardware_Design
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16 DO Clock signal of USIM card.
17 DO Reset signal of USIM card.
13 DI USIM card insertion detection.
10 Specified ground for USIM card.
VDD_EXT
51K
USIM_GND
USIM_VDD
USIM_RST
USIM_CLK
USIM_PRESENCE
USIM_DATA
Figure 22: Reference Circuit of the 8 Pin USIM Card
USIM_VDD
15K
100nF
22R
22R
22R
33pF 33pF 33pF
GND
Confidential / Released
UMTS/HSPA Module Series
UC20 Hardware Design
1.8V power domain.
USIM Connector
VCC
RST
CLK
GND
GND
VPP
IO
GND
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