Figure 17: Reference Circuit Of 8-Pin Usim Connector - Quectel EC25-V User Manual

EC25 supports USIM card hot-plug via the USIM_PRESENCE pin. It supports low level and high level
detections, which is disabled by default. For details, refer to document [2] about the command
AT+QSIMDET.
The following figure shows the reference design of the 8-pin USIM connector.
USIM_GND
USIM_VDD
USIM_RST
Module
USIM_CLK
USIM_PRESENCE
USIM_DATA
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 in the following figure.
USIM_GND
USIM_VDD
USIM_RST
Module
USIM_CLK
USIM_DATA
In order to enhance the reliability and availability of the USIM card in your application, please follow the
EC25-V_User_Manual
69
VDD_EXT USIM_VDD
51K
22R
22R
22R
33pF 33pF 33pF

Figure 17: Reference Circuit of 8-Pin USIM Connector

USIM_VDD
15K
22R
22R
22R
33pF 33pF 33pF
Figure 18: Reference Circuit of 6-Pin USIM Connector
Confidential / Released
15K
100nF
GND GND
100nF
GND GND
LTE Module Series
EC25-V User Manual
USIM Connector
VCC GND
RST VPP
IO
CLK
GND
USIM Connector
VCC GND
RST VPP
CLK IO
33 /