Sim Switch And Card Detection - Nokia 2650 Service Manual

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Nokia Customer Care 8-System Module

SIM switch and card detection

The SIM power up/down sequence is generated in the UEM. This means that the UEM gener-
ates the RST signal to the SIM. A mechanical switch is connected to UEM SimCardDet pin to
monitor the presence of the SIM card, i.e. card detection. When the SIM card is inserted, the
switch connects the SimCardDet to GND.
To avoid probable SIM card corruption caused by "hot-swapping", the UEM will automatically
power down the SIM card interface within 2ms if the switch is opened.
Figure 11:SIM draw and switch
30 COMPANY CONFIDENTIAL Issue 2 06/2005
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