Power Output; Battery Charging And Management - Quectel SC20 Series Hardware Design

If RTC is ineffective, it can be synchronized through network after the module is powered on.
The input voltage range is 2.0–3.25 V and the typical value is 3.0 V for VRTC. When VBAT is

disconnected, the average consumption is about 5 μA.
When powered by VBAT, the RTC error is 50 ppm. When powered by VRTC, the RTC error is

200 ppm.
If a rechargeable battery is used, the ESR of the battery should be less than 2 kΩ, and it is

recommended to use the MS621FE-FL11E of SEIKO.
If a large-capacitance capacitor is selected, it is recommended to use a 100 μF capacitor with low

ESR. The capacitor will be able to power the real-time clock for 45 seconds.

3.7. Power Output

SC20 series supports output of regulated voltages for peripheral circuits. During application, it is
recommended to add capacitors (33 pF and 10 pF) in parallel to suppress high frequency noise.
Table 10: Power Description
Pin Name
LDO5_1V8
LDO6_1V8
LDO17_2V85
SD_LDO12
SD_LDO11
USIM1_VDD
USIM2_VDD

3.8. Battery Charging and Management

SC20 series can supports battery charging. The battery charger in the module supports trickle charging,
constant current charging and constant voltage charging modes, which optimize the charging procedure
for Li-ion batteries.
SC20_Series_Hardware_Design
Default Voltage (V)
1.8
1.8
2.85
1.8/2.95
2.95
1.8/2.95
1.8/2.95
Driving Current (mA)
20
100
300
50
600
50
50
Smart Module Series
Idle
Keep
-
-
-
-
-
-
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