Supertex inc.
does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receives an
adequate “product liability indemnification insurance agreement.”
Supertex inc.
does not assume responsibility for use of devices described, and limits its liability to the
replacement of the devices determined defective due to workmanship. No responsibility is assumed for possible omissions and inaccuracies. Circuitry and specifications
are subject to change without notice. For the latest product specifications refer to the
Supertex inc.
website: http//www.supertex.com.
©2009
All rights reserved. Unauthorized use or reproduction is prohibited.
1235 Bordeaux Drive, Sunnyvale, CA 94089
Tel: 408-222-8888
www.supertex.com
3
DN-H01
Flyback Transformer Details
Component
Description
Core :
EFD20/10/7 – 3C90 – A250 from Ferroxcube
(EFD 20 core with 160µm gap in the center leg)
Bobbin:
CPHS – EFD20 – 1S – 10P from Ferroxcube
Primary:
66 turns of AWG#32 magnet wire
Secondary:
13 turns of AWG#24 equivalent triple-insulated litz wire
Auxiliary:
32 turns of AWG#32 magnet wire
Insulation:
3M 1928 Polyester Film, 2.0 mil thick tape
Schematic Diagram of the Transformer
Primary
Auxiliary
Secondary
1
3
9
10
4
5
O
O
O
T1
Pin 1
Pin 3
Pin 5
Pin 4
Pins 6, 7
Pins 9, 10
Primary Side
Secondary Side
AWG #24
AWG #32
AWG #32
2 Layers Tape
2 Layers Tape
2 Layers Tape
L
PRIMARY
= 1.1mH ± 8%
Leakage inductance = 8% of L
PRIMARY
022009
Winding Diagram