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2 W, 3-phase SMPS for breaker applications
Features
■ Active startup network for improved efficiency
■ Input voltage: 150 to 1250 VDC
■ Output voltage: 24 V / 83 mA
■ Output power: 2 W
■ Switching frequency: 30 kHz
■ Dedicated transformer construction
■ Efficiency: > 80%
■ RoHS compliant
STEVAL-IPB001V1
based on the STC04IE170HP ESBT
Data brief
Description
The design implemented in the STEVALIPB001V1 demonstration board represents a
complete solution for a 2 W single-output SMPS
(switched-mode power supply), which is widely
used to supply power in breaker applications.
The SMPS employs the UC3845B PWM driver,
and uses the STC04IE170HP ESBT as the main
switch.
This design can also be applied to power supplies
for 3-phase power metering applications, as it can
be easily upgraded for higher output power.
STEVAL-IPB001V1
November 2010 Doc ID 18241 Rev 1 1/4
For further information contact your local STMicroelectronics sales office.
www.st.com
4
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Schematic diagram STEVAL-IPB001V1
1 Schematic diagram
Figure 1. STEVAL-IPB001V1 circuit schematic
D5
20V
330uF 25V
C3
D3
1N4148
J2
1
2
CON2
C1
220uF 35V
47uF 25V
C4
R23
Q4
R6
10k
STC04IE170HP
1
3
4
2
6.8
R3 1
D1
7
T1
4
D2
STTH110
8
STTH110
2
1
5
R2
R5
10k 1/4W
R8
10k 1/4W
R10
10k 1/4W
R24
10k 1/4W
R25
10k 1/4W
Q3
10k 1/4W
STP03D200
2
3
1
Q2
PN2222A
1
3
2
R13
R12
1M 1/8W
R11
R1
1M 1/8W
R4
1M 1/8W
C2
33uF450V
R7
1M 1/8W
C5
R9
33uF 450V
1M 1/8W
1M 1/8W
C6
33uF 450V
680k
C7
10nF
R26 10
R22
10k
STTH110
D4
R15 3.3k
R19 1k
R17 22
C11
100nF
7
U1
VFB2COMP1VREF
C9
820pF
3
6
OUT
VCC
GND
SENSE
5
RT/CT
4
8
UC3845B
C10
R18 2.2k
C8 100p
R16 150k
R14
18k
12nF
R21
3.9k
R20
100k
123
J1
CON3
2/4 Doc ID 18241 Rev 1
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