Turn Off Module; Turn Off Module Using The Pwrkey Pin; Turn Off Module Using At Command - Quectel EC21 Series Hardware Design

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 PWRKEY pin.

Normal power down procedure: Turn off the module using AT+QPOWD command.

3.7.2.1. Turn off Module Using the PWRKEY Pin

Driving the PWRKEY pin to a low level voltage for at least 650ms, the module will execute power-down
procedure after the PWRKEY is released. The power-down scenario is illustrated in the following figure.
VBAT
PWRKEY
STATUS
(OD)
Module
Status

3.7.2.2. Turn off Module Using AT Command

It is also a safe way to use AT+QPOWD command to turn off the module, which is similar to turning off the
module via PWRKEY pin.
Please refer to document [2] for details about AT+QPOWD command.
NOTE
In order to avoid damaging internal flash, please do not switch off the power supply when the module
works normally. Only after the module is shut down by PWRKEY or AT command, the power supply can
be cut off.
EC21_Hardware_Design
≥650ms
RUNNING
Figure 13: Timing of Turning off Module
Confidential / Released
≥
29.5s
Power-down procedure
LTE Module Series
EC21 Hardware Design
OFF
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