
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

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
!-V

STEVAL-IPB001V1 Revision history
2 Revision history
Table 1. Document revision history
Date Revision Changes
18-Nov-2010 1 Initial release.
Doc ID 18241 Rev 1 3/4

STEVAL-IPB001V1
Please Read Carefully:
Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the
right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any
time, without notice.
All ST products are sold pursuant to ST’s terms and conditions of sale.
Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no
liability whatsoever relating to the choice, selection or use of the ST products and services described herein.
No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this
document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products
or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such
third party products or services or any intellectual property contained therein.
UNLESS OTHERWISE SET FORTH IN ST’S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED
WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS
OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT.
UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE, ST PRODUCTS ARE NOT
RECOMMENDED, AUTHORIZED OR WARRANTED FOR USE IN MILITARY, AIR CRAFT, SPACE, LIFE SAVING, OR LIFE SUSTAINING
APPLICATIONS, NOR IN PRODUCTS OR SYSTEMS WHERE FAILURE OR MALFUNCTION MAY RESULT IN PERSONAL INJURY,
DEATH, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. ST PRODUCTS WHICH ARE NOT SPECIFIED AS "AUTOMOTIVE
GRADE" MAY ONLY BE USED IN AUTOMOTIVE APPLICATIONS AT USER’S OWN RISK.
Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void
any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any
liability of ST.
ST and the ST logo are trademarks or registered trademarks of ST in various countries.
Information in this document supersedes and replaces all information previously supplied.
The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners.
© 2010 STMicroelectronics - All rights reserved
Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan -
STMicroelectronics group of companies
Malaysia - Malta - Morocco - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America
www.st.com
4/4 Doc ID 18241 Rev 1