DER-42

Portable CD Player – LNK520P

November 18, 2004

Table Of Contents

1

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

2

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

3

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

4

Circuit Description.......................................................................................................6

4.1

Input EMI Filtering................................................................................................6

4.2

LinkSwitch Primary ..............................................................................................6

4.3

Output Rectification .............................................................................................6

5

PCB Layout.................................................................................................................7

6

Bill Of Materials...........................................................................................................8

7

Transformer Specification ...........................................................................................9

7.1

Transformer Winding ...........................................................................................9

7.1.1

Electrical Specifications................................................................................9

8

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

9

Performance Data.....................................................................................................12

9.1

Efficiency ...........................................................................................................12

9.2

No-load Input Power ..........................................................................................13

9.3

Output Voltage Regulation.................................................................................13

9.4

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

9.4.1

Ripple Measurement Technique.................................................................14

10

AM Radio Reception Test .....................................................................................15

11

Conducted EMI .....................................................................................................16

12

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

Important Note:

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.

Page 2 of 19

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