Datasheet
NCP1010, NCP1011, NCP1012, NCP1013, NCP1014
http://onsemi.com
19
Typical Application Examples
A 6.5 W NCP1012--Based Flyback Converter
Figure 28 shows a converter built with a NCP1012
delivering 6.5 W from a universal input. The board uses the
Dynamic Self--Supply and a simplified Zener--type
feedback. This configuration was selected for cost reasons
and a more precise circuitry can be used, e.g. based on a
TL431:
Figure 28. An NCP1012--Based Flyback Converter Delivering 6.5 W
1
2
J1
CEE7.5/2
D1 D2
E1
10 m/400 V
E2
10 m/16 V
2
3
7
2
1
GND
GND
GND
V
CC
HV
FB
GND
IC1
NCP1012
R2
150 k
D5
U160
5
4
4
8
C2
2n2/Y
4
8
7
6
5
TR1
1
E3
470 m/25 V
D6
B150
R3
100 R
R4
180 R
2
1
ZD1
11 V
J2
CZM5/2
IC2
PC817
C1
2.2 nF
1N4007 1N4007
R1
47 R
D3 D4
1N4007 1N4007
The converter built according to Figure 29 layouts, gave
the following results:
Efficiency at Vin = 100 Vac and Pout = 6.5 W = 75.7%
Efficiency at Vin = 230 Vac and Pout = 6.5 W = 76.5%
Figure 29. The NCP1012--Based PCB Layout ...anditsAssociatedComponent Placement