DER-113

5 W Charger for Portable Audio Player

July 19, 2006

Page 2 of 25

Power Integrations

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Table Of Contents

1

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

2

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

3

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

4

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

4.1

Primary clamp snubber........................................................................................6

4.2

Bias supply ..........................................................................................................6

4.3

CVCC circuit ........................................................................................................6

5

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

6

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

7

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

7.1

Electrical Diagram................................................................................................9

7.2

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

7.3

Materials ..............................................................................................................9

7.4

Transformer Build Diagram................................................................................10

7.5

Transformer Construction ..................................................................................10

8

Transformer Spreadsheets .......................................................................................11

9

Performance Data.....................................................................................................14

9.1

Efficiency ...........................................................................................................14

9.1.1

Active Mode CEC Measurement Data ........................................................15

9.2

No-load Input Power ..........................................................................................16

9.3

Regulation .........................................................................................................16

9.3.1

Output Characteristic..................................................................................16

10

Thermal Performance............................................................................................17

11

Waveforms ............................................................................................................18

11.1

Drain Voltage and Current, Normal Operation ...................................................18

11.2

Output Voltage Start-up Profile ..........................................................................18

11.3

Drain Voltage and Current Start-up Profile ........................................................19

11.4

Load Transient Response (75% to 100% Load Step)........................................20

11.5

Output Ripple Measurements ............................................................................21

11.5.1

Ripple Measurement Technique.................................................................21

11.5.2

Measurement Results.................................................................................22

12

Conducted EMI .....................................................................................................23

13

Revision History ....................................................................................................24

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.