Quectel EC25-AUX Hardware Design page 49

Table 9: Pin Definition of (U)SIM Interface
Pin Name Pin No.
USIM_VDD 14
USIM_DATA 15
USIM_CLK 16
USIM_RST 17
USIM_
13
PRESENCE
USIM_GND 10
EC25 supports (U)SIM card hot-plug via the USIM_PRESENCE pin. The function supports low level and
high level detections, and is disabled by default. Please refer to document [2] for more details about
AT+QSIMDET command.
The following figure shows a reference design for (U)SIM interface with an 8-pin (U)SIM card connector.
Figure 17: 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.
EC25_Hardware_Design
I/O Description
PO Power supply for (U)SIM card
IO Data signal of (U)SIM card
DO Clock signal of (U)SIM card
DO Reset signal of (U)SIM card
DI (U)SIM card insertion detection
Specified ground for (U)SIM card
LTE Standard Module Series
EC25 Hardware Design
Comment
Either 1.8V or 3.0V is supported
by the module automatically.
1.8V power domain.
If unused, keep it open.
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