Vrtc Interface; Power Output - Quectel SC262R Series Hardware Design

Smart Module Series
VBAT
> 8 s
PWRKEY
Others
Power down
Figure 9: Timing of Turning Off the Module

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 VBAT. The external power source can be a
rechargeable battery (such as a coin cell) according to application demands. A reference circuit design is
shown below.
VRTC
RTC
Core
Coin Cell
Module
Figure 10: RTC Powered by Coin Cell
If RTC is ineffective, it can be synchronized through the network after the module is powered on. The
recommended input voltage range for VRTC is 2.0–3.25 V and the recommended typical value is 3.0 V.

3.7. Power Output

SC262R series module supports output of regulated voltages for peripheral circuits. During application, it
is recommended to connect a 33 pF and a 10 pF capacitor in parallel in the circuit to suppress
high-frequency noise.
SC262R_Series_Hardware_Design 40 / 115