N720 OpenLinux
Hardware User Guide
Copyright © Neoway Technology Co., Ltd
18
Figure 3-4 Recommended design 3
U1
100 μF
TAN
100 kΩ
0.1 μF
47.5 kΩ
470 μF
TAN
0.1 μF
TVS
5V
EN
VIN
VOUT
ADJ
10 μF
100 pF
33 pF
GND
GND
PWR_EN
VIN (5V)
VBAT
The power input is similar to that of VBAT. Select an LDO, which can facilitate design and
provide stable power.
Select an LDO that can output a current larger than 2A at U1 to ensure the stable functioning of
the module. MIC29302WU is recommended.
TVS diodes work in the same way as those in Figure 3-2 and they should meet the same
requirements.
Figure 3-5 shows schematic design recommended for 5.5V-24V input.
Figure 3-5 Recommended design 4
VIN
EN
RT/CLK
P-PAD
GND
BOOST
SW
FB
COMP
R1
47.5kΩ
12kΩ
100pF
0.01uF
L1
3.3uH
0.1uF
470uF
1kΩ
47.5k
Ω
12kΩ
SS36
VIN
(5.5V-42V)
C1
100uF
C2
22uF
C3
0.1uF
TPS54340
D1
C4
C5
C6
C7
R2
R2
R3
R4
Close to the pin of the module
VBAT
TVS
C8
C9
C10
C11
C12
470uF
10uF
0.1uF 100pF
33pF
5V
N720
Module
PWR_EN
U1
Select DC-DC that can output a maximum current larger than 2A when the output of power
supply is much larger than the permissible voltage across VBAT. TPS54340 outputs 3.5A current
at most.
500 kHz or larger switching frequency is recommended for DC-DC. The inductance depends on
the switching frequency. The switching frequency might produce EMC noise and it determines
the performance of end products.
For more design guidelines, see TPS54340 datasheet.