EPR-32 - 25 W Multiple Output TOP245P Supply

13-Jul-06

Page 2 of 36

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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

TOPSwitch-GX

Primary.......................................................................................6

4.3

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

4.4

Output Feedback and Control .............................................................................7

4.5

Secondary 3.3 V and 5 V Shunt Regulator..........................................................8

5

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

6

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

7

Transformer Specification.........................................................................................12

7.1

Electrical Diagram .............................................................................................12

7.2

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

7.3

Materials............................................................................................................13

7.4

Transformer Build Diagram ...............................................................................13

7.5

Transformer Winding Construction....................................................................14

7.6

Bobbin Drawing .................................................................................................15

8

Transformer Spreadsheet.........................................................................................16

9

Performance Data ....................................................................................................18

9.1

Efficiency ...........................................................................................................18

9.2

No-load Input Power..........................................................................................19

9.3

Regulation .........................................................................................................20

10

Thermal Performance ...........................................................................................21

11

Waveforms............................................................................................................22

11.1 Drain Voltage and Current Waveforms..............................................................22

11.2 Output Voltage Start-up Profile..........................................................................23

11.3 Load Transient Response .................................................................................23

11.4 Output Ripple Measurements............................................................................25

11.4.1

Ripple Measurement Technique ................................................................25

11.4.2

Measurement Results ................................................................................26

12

Control Loop Gain/Phase Measurements .............................................................27

12.1 115 VAC Maximum Load...................................................................................27

12.2 115 VAC 50% Load...........................................................................................27

12.3 115 VAC Minimum Load....................................................................................28

12.4 230 VAC Maximum Load...................................................................................28

12.5 230 VAC 50% Load...........................................................................................29

12.6 230 VAC Minimum Load....................................................................................29

13

Conducted EMI .....................................................................................................30

14

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

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.