LTE Standard Module Series
EC25 Hardware Design
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Table 9: Pin Definition of (U)SIM Interface
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.
Pin Name
Pin No.
I/O
Description
Comment
USIM_VDD
14
PO
Power supply for (U)SIM card
Either 1.8V or 3.0V is supported
by the module automatically.
USIM_DATA 15
IO
Data signal of (U)SIM card
USIM_CLK
16
DO
Clock signal of (U)SIM card
USIM_RST
17
DO
Reset signal of (U)SIM card
USIM_
PRESENCE
13
DI
(U)SIM card insertion detection
1.8V power domain.
If unused, keep it open.
USIM_GND
10
Specified ground for (U)SIM card