EPR-33 – 45 W External Adapter Supply

28-Mar-2003

Page 2 of 32

Power Integrations, Inc.

Tel: +1 408 414 9200 Fax: +1 408 414 9201

www.powerint.com

Table Of Contents

1

Introduction ........................................................................................................................... 4

2

Power Supply Specification................................................................................................... 5

3

Schematic ............................................................................................................................. 6

4

Circuit Description ................................................................................................................. 7

4.1

Input EMI Filtering ......................................................................................................... 7

4.2

TOPSwitch-GX Primary................................................................................................. 7

4.3

Output Rectification ....................................................................................................... 7

4.4

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

5

PCB Layout........................................................................................................................... 9

6

Bill Of Materials................................................................................................................... 10

7

Transformer Specification ................................................................................................... 11

7.1

Electrical Specifications............................................................................................... 11

7.2

Materials...................................................................................................................... 11

7.3

Transformer Build Diagram.......................................................................................... 12

7.4

Transformer Construction ............................................................................................ 12

7.5

Transformer Sources................................................................................................... 12

8

Transformer Spreadsheet ................................................................................................... 13

9

Performance Data ............................................................................................................... 15

9.1

Efficiency..................................................................................................................... 15

9.2

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

9.3

Input Power at 0.5 W Load .......................................................................................... 16

9.4

Regulation ................................................................................................................... 17

9.4.1

Load .................................................................................................................... 17

9.4.2

Line ..................................................................................................................... 17

10

Thermal Performance...................................................................................................... 18

11

Waveforms...................................................................................................................... 19

11.1

Drain Voltage and Current, Normal Operation ............................................................. 19

11.2

Output Voltage Start-up Profile.................................................................................... 20

11.3

Drain Voltage and Current Start-up Profile .................................................................. 21

11.4

Load Transient Response (75% to 100% Load Step) .................................................. 22

11.5

Output Ripple Measurements ...................................................................................... 23

11.5.1

Ripple Measurement Technique .......................................................................... 23

11.5.2

Measurement Results.......................................................................................... 24

12

Control Loop Measurements ........................................................................................... 25

12.1

115 VAC Maximum Load............................................................................................. 25

12.2

230 VAC Maximum Load............................................................................................. 26

13

Conducted EMI ............................................................................................................... 27

14

AC Surge and 100 kHz Ring Wave Immunity .................................................................. 28

14.1 Common Mode Surge, 1.2/50

µsec................................................................................. 28

14.2

Differential Mode Surge, 1.2/50

µsec........................................................................... 28

14.3

Common Mode, 100 kHz Ring Wave........................................................................... 29

14.4

Differential Mode, 100 kHz Ring Wave ........................................................................ 29

15

Appendix ......................................................................................................................... 30

15.1

Input Cable Bill of Materials ......................................................................................... 30

15.2

Input Cable Assembly.................................................................................................. 30

15.3

Heat Sink Assembly .................................................................................................... 31

16

Revision History .............................................................................................................. 32