HUAWEI ME909u-521 LTE LGA Module
Hardware Guide
Description of the Application Interfaces
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
3.4.2 Power-on/off (POWER_ON_OFF) Pin
The ME909u-521 module can be controlled to be powered on/off by the
POWER_ON_OFF pin.
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 sequence, please make sure the VBAT is stable.
Figure 3-4 Power on timing sequence
Table 3-4 Power on timing
POWER_ON_OFF turn on time.
POWER_ON_OFF Valid to USB D+ high
If the DTE needs to detect the PID/VID of module during the BIOS phase, the
detection time should exceed the T
PD+
time.