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3.
5
UIM Interface
IMA2 modules provide a UIM_DETECT input pin for UIM connectors to detect a UIM
card. When a UIM card is present, UIM_DETECT should be high (1.8 V). If a UIM card
is absent, UIM_DETECT should be low. Pulling UIM_DETECT to VREF with a 100k
resistor is necessary. We recommend placing a 0.1 μF and a 33 pF capacitor between
UIM_VCC and the Ground in parallel. We also recommend placing a 33 pF capacitor
between UIM_RESET, UIM_CLK, and UIM_DATA and the Ground in parallel. Refer to
Figure 5 for details.
We also recommend placing an electrostatic discharge (ESD) protection circuit near
the UIM socket as close as possible. The Ground pin of the ESD protection
component must be well-connected to the Ground plane.
The following figure shows an example of a UIM card circuit. The default
configuration is active High.
Figure 3-2. UIM card circuit example
