Product Info

LTE Standard Module Series
EC25 Hardware Design
EC25_Hardware_Design 49 / 112
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