User's Manual

UMTS/HSDPA Module Series
UC15 Hardware Design
UC15_Hardware_Design Confidential / Released 32 / 78
The turn on scenarios is illustrated as the following figure.
Figure 10: Timing of Turning on Module
① Make sure that VBAT is stable before pulling down PWRKEY pin. The time between them is
recommended to be more than 0.03s.
3.7.2. Turn off Module
The following procedures can be used to turn off the module:
 Normal power down procedure: Turn off the module by PWRKEY pin.
 Normal power down procedure: Turn off the module by command AT+QPOWD.
 Automatic shutdown: Turn off the module automatically if under-voltage or over-voltage is detected.
3.7.2.1. Turn off Module by PWRKEY Pin
Drive the PWRKEY to low level at least 0.6s, the module will execute power-down procedure after
PWRKEY is released. The power-down scenario is illustrated as the following figure.
NOTE