User's Manual

UMTS/HSPA Module Series
UG95 Hardware Design
UG95_Hardware_Design Confidential / Released 28 / 67
V
IL
≤ 0.5V
V
IH
≥ 1.3V
VBAT
PWRKEY
(Input)
≥ 100ms
OFF
BOOTING
Module
Status
RUNNING
1
≥ 3.5s
RESET_N
STATUS
>2.3s
Figure 9: Timing of Turning on Module
① Make sure that VBAT is stable before pulling down PWRKEY pin. It is suggested to pull down
PWRKEY pin after VBAT is stable 30ms at a voltage of 3.8V. It is not suggested to pull down
PWRKEY pin always.
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 using the PWRDWN_N pin.
 Normal power down procedure: Turn off the module using 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 Using the PWRDWN_N Pin
The following table shows the pin definition of PWRDWN_N.
NOTE