EP68 3.3 V, 2 A DC-DC Power Supply
19-Jul-2005
Table Of Contents
1
2
3
4
Introduction..................................................................................................................3
Power Supply Specification.........................................................................................4
Schematic ...................................................................................................................5
Circuit Description .......................................................................................................6
4.1
4.2
4.3
DPA-Switch Primary............................................................................................6
Output Rectification.............................................................................................6
Output Feedback.................................................................................................7
5
6
7
PCB Layout .................................................................................................................7
Bill of Materials............................................................................................................8
Transformer Specification ...........................................................................................9
7.1
Electrical Diagram ...............................................................................................9
Electrical Specifications.......................................................................................9
Materials..............................................................................................................9
Transformer Build Diagram ...............................................................................10
Transformer Construction..................................................................................10
7.2
7.3
7.4
7.5
8
9
Transformer Spreadsheet .........................................................................................11
Performance Data .....................................................................................................13
9.1
9.2
Efficiency...........................................................................................................13
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: +1 408 414 9200 Fax: +1 408 414 9201
www.powerint.com
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