DER-49

-12V/3W, Non-Isolated Buck-Boost Converter

April 20, 2005

Page 2 of 17

Power Integrations

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Table Of Contents

1

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

2

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

3

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

4

Circuit Description ............................................................................................................5

5

PCB Layout......................................................................................................................6

6

Bill Of Materials ................................................................................................................7

7

Performance Data ............................................................................................................8

7.1

Efficiency...................................................................................................................8

7.2

No-load Input Power .................................................................................................8

7.3

Regulation.................................................................................................................9

7.3.1

Load...................................................................................................................9

7.3.2

Line ....................................................................................................................9

8

Waveforms.....................................................................................................................10

8.1

Source Voltage and Current, Normal Operation .....................................................10

8.2

Output Voltage Start-up Profile ...............................................................................10

8.3

Load Transient Response (75% to 100% Load Step) .............................................11

8.4

Output Ripple Measurements .................................................................................12

8.4.1

Ripple Measurement Technique ......................................................................12

8.4.2

Measurement Results ......................................................................................13

9

Conducted EMI ..............................................................................................................14

10

Revision History..........................................................................................................15

Important Note:

Although this board is designed to satisfy safety requirements, the engineering prototype has

not been agency approved. In addition, as the output is not electrically isolated from the

input, all testing should be performed using an isolation transformer to provide the AC line

input to the prototype board.

Design Reports contain a power supply design specification, schematic, bill of materials, and

transformer documentation. Performance data and typical operation characteristics are

included. Typically only a single prototype has been built.