EPR-68 Datasheet, PDF (2/28 Pages) Power Integrations, Inc. – Engineering Prototype Report for EP 68 - 6.6 W DC-DC Flyback Converter Using DPA-Switch- (DPA423G)

EP68 3.3 V, 2 A DC-DC Power Supply
19-Jul-2005
Table Of Contents
1 Introduction..................................................................................................................3
2 Power Supply Specification .........................................................................................4
3 Schematic ...................................................................................................................5
4 Circuit Description .......................................................................................................6
4.1 DPA-Switch Primary............................................................................................6
4.2 Output Rectification .............................................................................................6
4.3 Output Feedback.................................................................................................7
5 PCB Layout .................................................................................................................7
6 Bill of Materials ............................................................................................................8
7 Transformer Specification ...........................................................................................9
7.1 Electrical Diagram ...............................................................................................9
7.2 Electrical Specifications.......................................................................................9
7.3 Materials..............................................................................................................9
7.4 Transformer Build Diagram ...............................................................................10
7.5 Transformer Construction..................................................................................10
8 Transformer Spreadsheet .........................................................................................11
9 Performance Data .....................................................................................................13
9.1 Efficiency ...........................................................................................................13
9.2 Regulation .........................................................................................................14
9.2.1 Load...............................................................................................................14
9.2.2 Line ................................................................................................................14
9.3 Peak Power .......................................................................................................15
10 Waveforms ................................................................................................................15
10.1 Drain Voltage and Current, Full Load Operation ...............................................15
10.2 Output Voltage Start-Up Profile .........................................................................16
10.3 Drain Voltage and Current Start-Up Profile .......................................................16
10.4 Load Transient Response (75% to 100% Load Step) .......................................17
10.5 Output Ripple Measurements............................................................................18
10.5.1 Ripple Measurement Technique ....................................................................18
10.5.2 Output Ripple Measurements ........................................................................19
11 Thermal Performance................................................................................................20
12 Control Loop Measurements .....................................................................................22
12.1 36 VDC Maximum and Nominal Load ...............................................................22
12.2 57 VDC Maximum Load ....................................................................................23
13 Revision History ........................................................................................................24
Important Note:
Although this board is designed to satisfy safety telecom isolation requirements, this
engineering prototype has not been agency approved.
Power Integrations
Tel: [phone] Fax: [phone]
www.powerint.com
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