Turn Off/Restart The Module; Vrtc Interface - Quectel Smart Module Series Hardware Design

3.5.3. Turn off/Restart the Module

Pull down PWRKEY for at least 1 s, and then choose to turn off the module when a prompt window comes
up.
Another way to restart the module is to drive PWRKEY low for at least 8 s. The module will execute forced
restart. The forced restart timing is illustrated in the following figure.
VBAT
PWRKEY
Others

3.6. VRTC Interface

The RTC (Real Time Clock) can be powered by an external power source through VRTC when the
module is powered down and there is no power supply for the VBAT. The external power source can be a
rechargeable battery (such as coin cell) according to application demands. The following reference circuit
design shows a design where an external battery is utilized to power RTC.
SA800U-WF_Hardware_Design
Figure 10: Timing of Restarting the Module
Coin Cell
Figure 11: RTC Powered by Coin Cell
> 8 s
Restart
VRTC
Smart Module Series
SA800U-WF Hardware Design
RTC
Core
Module
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