EPR-21 – 5 V, 30 W DC-DC Converter
19-Nov-02
Table Of Contents
1
2
3
4
Introduction.................................................................................................................3
Power Supply Specification ........................................................................................4
Schematic...................................................................................................................5
Circuit Description.......................................................................................................6
4.1 Primary Circuitry......................................................................................................6
4.2 Output Rectification.................................................................................................6
4.3 Output Feedback.....................................................................................................7
4.4 Construction............................................................................................................7
PCB Layout.................................................................................................................8
Bill Of Materials...........................................................................................................9
5
6
Transformer Specification................................................................................................10
7.1 Electrical Specifications.........................................................................................10
7.2 Materials................................................................................................................10
7.3 Transformer Build Diagram ...................................................................................11
7.4 Transformer Construction......................................................................................11
8
Inductor Specification................................................................................................12
8.1 Electrical Specifications.........................................................................................12
8.2 Materials................................................................................................................12
8.3 Inductor Build Diagram..........................................................................................13
8.4 Inductor Construction............................................................................................13
PIXls Design Spreadsheet........................................................................................14
9
10 Performance Data.....................................................................................................17
10.1 Efficiency ...........................................................................................................17
10.2 Regulation .........................................................................................................18
10.2.1 Load Regulation.............................................................................................18
10.2.2 Line Regulation..............................................................................................18
11 Thermal Performance...............................................................................................19
12 Waveforms................................................................................................................21
12.1 Drain Voltage and Current, Normal Operation...................................................21
12.2 Output Voltage Start-up Profile..........................................................................22
12.3 Load Transient Response (75% to 100% Load Step)........................................23
12.4 Output Ripple Measurements............................................................................24
12.4.1 Ripple Measurement Technique ....................................................................24
12.4.2 Measurement Results ....................................................................................25
13 Control Loop Measurements.....................................................................................26
13.1 Maximum Load 36 VDC.....................................................................................26
13.2 Maximum Load 48 VDC.....................................................................................26
13.3 Maximum Load 72 VDC.....................................................................................27
14 Revision History........................................................................................................28
Important Note:
Although the EP-21 is designed to satisfy telecom safety isolation requirements, this
engineering prototype has not been agency approved.
Power Integrations, Inc.
Tel: +1 408 414 9660 Fax: +1 408 414 9760
Page 2 of 32
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