Huawei MU736 - Page 33

HUAWEI MU736 HSPA+ M.2 Module
Hardware Guide
Description of the Application Interfaces
Issue 05 (2014-01-14)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
33
Figure 3-21 Connections of the SIM_DET pin
CD is a pin detecting USIM in the SIM Socket, normally, there will be a detect pin in
the SIM Socket.

The Normal SHORT SIM connector should be employed. The logic of SIM_DET
pin is shown as Figure 3-22 . High represents that SIM is inserted; Low represents
that SIM is removed.

When SIM is inserted (hot), SIM_DET pin will change from Low to High;

When SIM is removed (hot), SIM_DET pin will change from High to Low.

MU736 will detect the rising or falling edge of SIM_DET to react the hot swap.
Figure 3-22 The logic of SIM_DET
Modem
Processor
SIM Connector Switch
SIM installed=
Not Connected
SIM not
installed=
GND
WWAN Module
SIM_DET
1.8V