DER-46
6 W peak, Multiple output PSU for DVB-T
April 20, 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
TinySwitch Primary............................................................................................. 6
Output Rectification ............................................................................................ 6
Output Feedback and control.............................................................................. 6
5
6
7
PCB Layout................................................................................................................ 7
Bill Of Materials.......................................................................................................... 8
Transformer Specification.......................................................................................... 9
7.1
Electrical Diagram............................................................................................... 9
Electrical Specifications ...................................................................................... 9
Materials ........................................................................................................... 10
Transformer Build Diagram............................................................................... 10
Winding Instructions.......................................................................................... 11
7.2
7.3
7.4
7.5
8
9
Transformer Spreadsheet........................................................................................ 12
Performance Data.................................................................................................... 13
9.1
9.2
10
11
Efficiency .......................................................................................................... 13
Worst Case Cross Regulation........................................................................... 14
Thermal Performance........................................................................................... 15
Waveforms ........................................................................................................... 15
11.1 Drain Voltage and Current, Normal Operation.................................................. 15
11.2 Output Ripple Measurements ........................................................................... 16
11.2.1 Ripple Measurement Technique................................................................ 16
11.2.2 Measurement Results................................................................................ 17
11.3 Transient Response: 3.3V – 50% - 100% Load Step........................................ 19
12
13
Conducted EMI..................................................................................................... 20
Revision History ................................................................................................... 21
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.
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.
Power Integrations
Tel: +1 408 414 9200 Fax: +1 408 414 9201
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