Turn On And Off Scenarios; Turn On Module Using The Pwrkey - Quectel SC20-WL Hardware Design

The following figure shows a reference design for +5V input power source which adopts an LDO
(MIC29302WU) from MICREL. The typical output voltage is 3.8V and the maximum rated current is 3.0A.
DC_IN
C1
100nF
470uF
NOTES
abnormal state, and then switch on the power to restart the module.
the above power supply design is adopted, please make sure the charging function is disabled by
software or connect VBAT to Schottky diode in series to avoid the reverse current to the power
supply chip.

3.5. Turn on and off Scenarios

3.5.1. Turn on Module Using the PWRKEY

The module can be turned on by driving PWRKEY pin to a low level for at least 1.6s. PWRKEY pin is
pulled to 1.8V internally. It is recommended to use an open drain/collector driver to control the PWRKEY.
A simple reference circuit is illustrated in the following figure.
SC20-WL_Hardware_Design
MIC29302WU
2
IN
R1
C2
51K
Figure 5: Reference Circuit of Power Supply
1. It is suggested to switch off the power supply for module in
2. The module supports battery charging function by default. If
U1
4
OUT
R2
100K
1%
R4
470R
R3
47K
1%
Smart Wi-Fi Module Series
SC20-WL Hardware Design
VBAT
C3
C4
100nF
470uF
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