EPR-00011 - 70 W Adapter

22-Jan-01

Page 2 of 46

Power Integrations Inc

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

www: http://www.powerint.com

Table of Contents

1

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

2

Power Supply Specification .........................................................................................6

3

Schematic ....................................................................................................................7

3.1 Description ...............................................................................................................7

4PCB Layout................................................................................................................10

5

Bill of Materials ..........................................................................................................11

6

Transformer Documentation ......................................................................................12

6.1 Transformer Sources .............................................................................................14

7

Transformer Spreadsheet..........................................................................................15

8

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

8.1 Efficiency................................................................................................................17

8.2 No-load input power...............................................................................................18

8.3 Regulation / Power Limiting ...................................................................................18

9

Thermal Performance ................................................................................................20

10 Waveform Scope Plots ..............................................................................................24

10.1

Drain Voltage and Current During Normal Operation.........................................24

10.2

Output Voltage During Power-up........................................................................25

10.3

Output Voltage During Power-down ...................................................................26

10.4

10.5

DRAIN Current During Power-Up and Power-Down...........................................27

10.6

Load Transient response (15 to 100% load change) .........................................28

10.7

Load Transient response (0 to 50% load change) .............................................29

10.8

Ripple Measurements.........................................................................................30

10.8.1 DC Ripple Measurement Technique...............................................................30

10.8.2 Ripple Measurement Results..........................................................................31

11 Control Loop Characteristics .....................................................................................32

11.1

Gain Phase Results............................................................................................33

12 Conducted EMI Scans ...............................................................................................36

Important Note:

Although the EP11 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