
STEVAL-ISA013V1
Dual output off-line wide range 24W power supply evaluation board
for VIPer53
Data Brief
Features
■ Switch mode general purpose power supply
■ Input: 85 to 264Vac @ 50/60Hz
■ Output: 12V @ 1A & 5V @ 2.4A
■ Output power (peak) : 24W
■ Switching frequency 100kHz
■ Current mode control
■ 75% efficiency
■ Auxiliary undervoltage lockout with hysteresis
■ Output short circuit protection
■ Thermal shutdown protection
■ Meets EN55022 Class B EMI specification
■ Meets Blue Angels
Description
This evaluation board is an off-line wide range
dual output general-purpose power supply
capable of delivering up to 24W through two
outputs, +5V and +12V. The board is configured
for secondary regulation with optocoupler
feedback.
ST components
■ VIPer53
■ STTA106
■ BYW98-200
■ TL431A
■ STPS5L40
■ 1.5KE220A
STEVAL-ISA013V1
Other output voltages can easily be achieved by
changing the transformer and a few components
on the board, as shown in the application note.
Transformers are readily available for the
following configurations:
■ 5V/12V
■ 5V/15V
■ 5V/24V
July 2007 Rev 1 1/5
For further information contact your local STMicroelectronics sales office
www.st.com
5

General circuit description STEVAL-ISA013V1
1 General circuit description
The evaluation board operates from 90 to 264Vac input with an output power peak of 24W
through two output voltages of +5V and +12V.
The AC input is rectified and filtered by the bridge BR1 and the bulk capacitor C2 to generate
the high voltage DC bus applied to the primary winding of the transformer, T1.
The switching frequency is set at 100kHz through R3 and C5.
Secondary regulation is provided by an optocoupler and a programmable voltage reference
(TL431).
The transformer is designed and manufactured by Cramer Coil and Transformer Company, Inc.
This evaluation board has an efficiency of 78% at 115Vac at full load for both outputs.
The evaluation board consumes less than 1W total power consumption when working in burst
mode during standby operation and therefore, meets Blue Angel norm.
2/5

STEVAL-ISA013V1 Board schematic
2 Board schematic
Figure 1. Scheme
1234J2
R10
C13
2.4A
5V @
L2
10uH
1Kv
470pF
D6
22
STPS5L40
2 1
8
9
.
.
.
5
12
D3
STTA106
25V
C9
330uF
C8
2700uF
16V
C19
2700uF
+
7
.
C14
100pF
R12
R2
22k
2W
C3
1kV
4700pF
D5
12V @ 1A
gnd
D4
1 2
16V
.6.11.
.1.
.
3
1k2W
D2
1.5KE220A
C16
1000uF
25V
+
+
C15
25V
1000uF
BYW98-200
10
2
STTA106
C10
4.7nF
Y1 cap
TX1
W1
1 2
0
7
1N4148
R3
3k
C2
68uF
400V
8
Vdd
TOVL
Osc2Source
Comp
U4
1
R4
15
D1
C4
R8
68
6
nc
3
100uF
25V
R7
1k
U2
12
43
C6
2.2nF
5
Drain
Source
VIPer53DIP
4
1%
2.49K
R9
LTV817
1 2
C5
W2
C12
0.01uF
R5
3.3KC7470nF
4.7nF
50V
C11
0.01uF
U3
TL431
1%
R6
2.49K
3
ST
2 1
0
KBP210GDI
3
BR1
1
4
-
+
2
C18
0.33uF
250V
L1
2 X 35mH
Line
21
43
C17
1
2
J1
0.33uF
250V
FUSE
0.047uF
C1
85 to 264Vac
CON2
250V
F1
2A 5X20mm
R1
5ohms
3W
AC in
All resistors are 1/4 W 5% unless specified.
All capacitors are in uF and 50 V unless
specified.
3/5

Revision history STEVAL-ISA013V1
3 Revision history
Table 1. Revision history
Date Revision Changes
20-Jul-2007 1 Initial release.
4/5

STEVAL-ISA013V1
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