HUAWEI ME909 Series LTE LGA Module
Hardware Guide
Description of the Application Interfaces
Issue V0.3 (2013-05-21)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
27
Power-On Time Sequence
After VBAT has been applied and is stable, the POWER_ON_OFF signal is pulled
down, and then the module will boot up.
During power on timing, please make sure the VBAT is stable.
Figure 3-6
Power on timing sequence
Table 3-5
Power on timing
Parameter Comments
Time (Nominal values) Units
T
PON
POWER_ON_OFF turn on time.
0.5
–1.0
s
T
PD+
POWER_ON_OFF Valid to USB
D+ high
12
s
If the DTE needs to detect the PID/VID of module during the BIOS phase, the
detection time should exceed the T
PD+
time.
Figure 3-7
Power off timing sequence
Table 3-6
Power off timing
Parameter
Comments
Time (Nominal values)
Units
T
POFF
POWER_ON_OFF turn off time. 3.0
–5.0
s