Huawei ME909s Series - Page 27

HUAWEI ME909s Series LTE Mini PCIe Module
Hardware Guide
Description of the Application Interfaces
Issue 02 (2016-09-07)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
27
Table 3-8 Function of the USIM_DET pin
No.
USIM_DET
Function
1
High level
USIM card insertion.
If the USIM card is present, USIM_DET should be High.
2
Low level
USIM card removal.
If the USIM card is absent, USIM_DET should be Low.
Figure 3-11 Connections of the USIM_DET pin
Module
(DCE)
1.8 V
USIM_DET
USIM Deck
470 pF
CD
1 kΩ
BB Chip
If USIM card is absent, the CD connects to Ground.
If USIM card is present, the CD is open.
CD is a pin detecting of USIM in the USIM socket, in normal, there will be a detect pin
in the USIM socket.

The normal USIM connector should be employed. The logic of USIM_DET is
shown as Figure 3-12 . High represents that USIM is inserted; Low represents that
USIM is removed.

When USIM is inserted (hot), USIM_DET will change from Low to High;

When USIM is removed (hot), USIM_DET will change from High to Low;

The module will detect the level of USIM_DET to support the hot swap.