DER-34

13W Integrated Digital TV PSU

April 1, 2004

Page 2 of 19

Power Integrations

Tel: +1 408 414 9660 Fax: +1 408 414 9760

www.powerint.com

Table Of Contents

1

Introduction................................................................................................................. 3

2

Power Supply Specification ........................................................................................ 4

3

Schematic................................................................................................................... 5

4

Circuit Description ...................................................................................................... 5

4.1

Design Architecture ............................................................................................. 6

4.2

Input Stage.......................................................................................................... 6

4.3

Primary Side Clamp ............................................................................................ 6

4.4

Output Rectification, Filtering and Feedback....................................................... 6

5

Bill Of Materials .......................................................................................................... 7

6

Transformer Specification........................................................................................... 8

6.1

Electrical Diagram ............................................................................................... 8

6.2

Electrical Specifications....................................................................................... 8

6.3

Materials.............................................................................................................. 8

6.4

Transformer Build Diagram ................................................................................. 9

6.5

Winding Instructions ............................................................................................ 9

7

Transformer Spreadsheet......................................................................................... 10

8

Measurements.......................................................................................................... 13

8.1

Efficiency........................................................................................................... 13

8.2

Line Regulation ................................................................................................. 13

9

Operating Waveforms .............................................................................................. 14

9.1

Output Ripple .................................................................................................... 14

9.1.1

High Frequency Ripple (132kHz) ............................................................... 15

9.1.2

Low frequency output ripple (100Hz) ......................................................... 16

10

Conducted EMI Measurements ............................................................................ 17

11

Revision History .................................................................................................... 18

Important Notes:

Although this board is designed to satisfy safety isolation requirements, the engineering

prototype has not been agency approved. Therefore, all testing should be performed

using an isolation transformer to provide the AC input to the prototype board.

Design Reports contain a power supply design specification, schematic, bill of materials,

and transformer documentation. Performance data and typical operation characteristics

are included. Typically only a single prototype has been built.