4 Circuit Design
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4.4.6.2
(U)SIM Card Connector Without Card Detection Signals
When you use an (U)SIM card connector without detection signals, USIM_PRESENCE pin
must be disconnected. The following figure shows the reference circuit.
Figure 19. SIM card connector without card detection signals
The USIM_DATA module needs to be pulled up externally. The
recommended model for RV1 to RV5 is EGA10402V05A2.
4.4.6.3
(U)SIM Hot Plugging
The LC116-LA module supports (U)SIM card hot plugging function. The module
determines whether the (U)SIM card is in place by detecting the state of the
USIM_PRESENCE pin. The (U)SIM card hot plugging function is enabled by default. When
the USIM_PRESENCE is at a high level, the module initializes the (U)SIM card after
detecting that the (U)SIM card is inserted, and registers the network after reading the
(U)SIM card information. When the USIM_PRESENCE is at a low level, the module
determines that the (U)SIM card is removed and does not read it. You can use the
AT+MSMPD=0 command to disable the hot plugging function if not required.
