Title 4.9W power supply using TNY266P Input: � 265 VAC Specification Output: 12V/0.5A, -12V/15mA Application Author Document Number Date Revision DVD Player Power Integrations Applications Department DER-10 February 2004 1.0

Summary and Features Low cost no common-mode choke no Y-cap no X-cap low EMI even with output grounded good output cross-regulation even with 200 mW input power during standby using low-cost "DC Switch"

The products and applications illustrated herein (including circuits external to the products and transformer construction) may be covered by one or more U.S. and foreign patents or potentially by pending U.S. and foreign patent applications assigned to Power Integrations. A complete list of Power Integrations' patents may be found at www.powerint.com.

Introduction................................................................................................................. 3 Photograph................................................................................................................. 4 Power Supply Specification........................................................................................ 5 Schematic................................................................................................................... 6 Circuit Description...................................................................................................... 7 5.1 Input EMI Filtering............................................................................................... 7 5.2 Primary Clamp Snubber...................................................................................... 7 5.3 Output filtering..................................................................................................... 7 5.4 Output Feedback................................................................................................. 7 5.5 "DC Switch"......................................................................................................... 7 6 PCB Layout................................................................................................................ 8 7 Bill Of Materials.......................................................................................................... 9 8 Transformer Specification......................................................................................... 10 8.1 Electrical Diagram............................................................................................. 10 8.2 Electrical Specifications..................................................................................... 10 8.3 Materials............................................................................................................ 10 8.4 Transformer Build Diagram............................................................................... 11 8.5 Copper Foil Preparation.................................................................................... 11 8.6 Transformer Construction.................................................................................. 12 9 Transformer Spreadsheets....................................................................................... 13 10 Performance Data................................................................................................. 16 10.1 Standby Input Power during DC switch off operation........................................ 16 10.2 Full-load Efficiency............................................................................................ 16 10.3 Input Power Consumption during Standby........................................................ 16 10.4 Cross Regulation............................................................................................... 17 Thermal Performance............................................................................................... 17 11 Minimum Operating Voltage and Peak Power Margin.......................................... 17 12 Output ripple and Noise Waveforms..................................................................... 18 13 Conducted EMI..................................................................................................... 20 14 Revision History.................................................................................................... 21 Important Notes: 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.

This document is an engineering report describing (8.5 W peak) multiple output power supply utilizing a TNY266P for a DVD player. This design is low cost and meets EMI with no common-mode choke, no X-cap, and no Y-cap. This is possible with TinySwitch-II because of its built-in frequency jitter. Cross-regulation is tight in spite of having a simple low-cost zener regulation scheme. This is possible with TinySwitch-II because of its unique feedback scheme. A low-cost non-Safety rated "DC Switch" allows shutdown with ~200 mW consumption at 230 Vac. This is possible with TinySwitch-II because of its EcoSmart features. This document contains the power supply specification, schematic, bill of materials, transformer documentation, printed circuit layout, and performance data.