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.
25
Figure 3-10
Recommended power off timing (connect to battery)
If there is limitation on the controlling GPIO to be programmable 500 ms, the hardware
solution can be used, as shown in Figure 3-11 .
Figure 3-11
Power on off circuit (hardware solution)
MU736
Pin 6
HOST
0
Ω
VCC
GPIO2
1M
Ω
NMOS
NMOS
3.3V (battery)
GPIO2
Q1
Q2
Power_On_Off
VCC
GPIO2
is the power domain of the GPIO2.
When
VCC
GPIO2
is
ON
, Q2 is on and Q1 is off. So the Pin6 is controlled by
GPIO2 of host.
When
VCC
GPIO2
is
Off
, Q2 is off and Q1 is on. So the Pin6 is pulled low,
then the module is powered off.
Power off
t1
≥ 500 ms
t1
Logic low or high-impedance (preferred)
Logic low or high-impedance (preferred)
Power_On_Off
RESET#
3.3V (Vbatt,
always on)