Reference Design For Power Supply - Quectel SC206E Series Hardware Design

3.4.3. Reference Design for Power Supply

The power design for the module is very important, as the performance of the module largely depends
on the power source. The power supply of the module should be able to provide sufficient current of 3 A
at least. If the voltage difference between the input and output is not too big, use an LDO when supplying
power to the module. If there is a big voltage difference between the input source and the desired output
(VBAT), a buck converter is recommended.
The following figure shows a reference design for +5 V input power source. The typical output voltage is
3.8 V and the maximum load current is 5.0 A.
VCC_5V
C2
C1 C3
D1
NOTE
1. In an abnormal state, it is recommended to restart the module by switching off and then switching
back on the power supply.
SC206E_Series_Hardware_Design
VBAT
+
D1
C2
C1 C3
4.7 μ F
100 nF
100 μ F
Figure 4: Reference Circuit for the Power Supply
R2
Q1
R1
C4
3V8_EN
R3
Figure 5: Reference Circuit of Power Supply
VBAT
C5
C4
33 pF 10 pF
GND
Module
U1
SW
PGND
PGND
SW
PGND
SW
VOS
PVIN
PG
PVIN
FB
PVIN
EN
FSW
SS/TR
DEF
GND
Smart Module Series
L1
R4 DC_3V8
R5
C5 C6
R6
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