Vrtc Interface - Quectel SG865W Series Hardware Design

VBAT
PWRKEY
Others

3.4. 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
capacitor according to application demands. The following are some reference circuit designs when an
external battery is utilized for powering RTC.
Large
Capacitance
Capacitor
SG865W_Series_Hardware_Design
Figure 11: Forced Power-down Timing
Coin Cell
Figure 12: RTC Powered by a Coin Cell
C
Figure 13: RTC Powered by Capacitor
> 8 s
Power down
VRTC
Module
VRTC
Module
Smart Module Series
RTC
Core
RTC
Core
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