EPR-21 – 5 V, 30 W DC-DC Converter

19-Nov-02

Table Of Contents

1

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

2

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

3

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

4

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

4.1 Primary Circuitry......................................................................................................6

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

4.3 Output Feedback.....................................................................................................7

4.4 Construction ............................................................................................................7

5

PCB Layout.................................................................................................................8

6

Bill Of Materials...........................................................................................................9

Transformer Specification ................................................................................................10

7.1 Electrical Specifications.........................................................................................10

7.2 Materials................................................................................................................10

7.3 Transformer Build Diagram ...................................................................................11

7.4 Transformer Construction......................................................................................11

8

Inductor Specification................................................................................................12

8.1 Electrical Specifications.........................................................................................12

8.2 Materials................................................................................................................12

8.3 Inductor Build Diagram..........................................................................................13

8.4 Inductor Construction ............................................................................................13

9

PIXls Design Spreadsheet ........................................................................................14

10 Performance Data.....................................................................................................17

10.1 Efficiency ...........................................................................................................17

10.2 Regulation .........................................................................................................18

10.2.1 Load Regulation .............................................................................................18

10.2.2 Line Regulation ..............................................................................................18

11 Thermal Performance ...............................................................................................19

12 Waveforms................................................................................................................21

12.1 Drain Voltage and Current, Normal Operation...................................................21

12.2 Output Voltage Start-up Profile..........................................................................22

12.3 Load Transient Response (75% to 100% Load Step)........................................23

12.4 Output Ripple Measurements ............................................................................24

12.4.1 Ripple Measurement Technique ....................................................................24

12.4.2 Measurement Results ....................................................................................25

13 Control Loop Measurements.....................................................................................26

13.1 Maximum Load 36 VDC.....................................................................................26

13.2 Maximum Load 48 VDC.....................................................................................26

13.3 Maximum Load 72 VDC.....................................................................................27

14 Revision History........................................................................................................28

Important Note:

Although the EP-21 is designed to satisfy telecom safety isolation requirements, this

engineering prototype has not been agency approved.

Page 2 of 32

Power Integrations, Inc.

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

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