TNY264

Design Example Report Title Generic PCB for DVD Player using TinySwitch-II Input: 90 – 265 VAC Specification Output: 5V/1.5A, 3.3V/1.5A, 12V/0.5A, -12V/15mA Application Author Document Number Date Revision DVD Player Power Integrations Applications Department DER-9 February 4, 2004 1.0 Summary and Features • • • • • • • • • • Multiple Output PCB using TinySwitch-II Suitable for multiple output DVD supplies Suitable for many different output configurations Uses 14-pin EEL25 core Low EMI even with output grounded 3 tested circuits shown: TNY264, TNY266, and TNY267 Low cost no common-mode choke, no Y-cap, no X-cap good output cross-regulation even with no TL431 ~ 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. Power Integrations 5245 Hellyer Avenue, San Jose, CA 95138 USA. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-9 Generic PCB for DVD Player using TinySwitch-II February 4, 2004 Table Of Contents 1 2 3 4 Introduction................................................................................................................. 3 Generic Power Supply PCB Layout............................................................................ 4 Schematic................................................................................................................... 5 Circuit Description ...................................................................................................... 6 4.1 Input EMI Filtering ............................................................................................... 6 4.2 Primary Clamp Snubber ...................................................................................... 6 4.3 Output filtering..................................................................................................... 6 4.4 Output Feedback................................................................................................. 6 4.5 “DC Switch” ......................................................................................................... 6 4.6 +8V Option .......................................................................................................... 6 4.7 –22V option ......................................................................................................... 6 4.8 Floating +3V and Its Bias Option......................................................................... 7 4.9 –12V Linear Regulator Option............................................................................. 7 Bill Of Materials – Generic PSU with all options ......................................................... 8 Example One - 5.7W TNY264 DVD PSU .................................................................. 9 6.1 DVD Power Requirements .................................................................................. 9 6.2 Schematic ......................................................................................................... 10 6.3 Bill Of Materials ................................................................................................. 11 6.4 Transformer Electrical Diagram......................................................................... 12 The Original 5.7W design in ASM-140292 used an EE19 core. 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Bookmark not defined. 6.5 Cross Regulation............................................................................................... 12 6.6 Design Option with EEL25 - Spreadsheet ......................................................... 12 Example Two - 8.5W TNY266 DVD PSU ................................................................ 15 7.1 Specification...................................................................................................... 15 7.2 Schematic ......................................................................................................... 16 7.3 Bill of Materials.................................................................................................. 17 7.4 Transformer Electrical Diagram......................................................................... 18 7.5 Cross Regulation............................................................................................... 18 Example Three – 11.6W TNY267 DVD PSU............................................................ 19 8.1 Specification...................................................................................................... 19 8.2 Schematic ......................................................................................................... 20 8.3 Bill of Materials.................................................................................................. 21 8.4 Transformer Electrical Diagram......................................................................... 22 8.5 Cross Regulation............................................................................................... 23 Revision History ....................................................................................................... 24 5 6 7 8 9 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. Page 2 of 25 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-9 Generic PCB for DVD Player using TinySwitch-II February 4, 2004 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. Page 3 of 26 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-9 Generic PCB for DVD Player using TinySwitch-II February 4, 2004 1 Introduction This document is an engineering report describing a generic multiple output power supply PCB layout utilizing TinySwitch-II for a wide range of application of DVD players. 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. Page 4 of 26 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-9 Generic PCB for DVD Player using TinySwitch-II February 4, 2004 2 Generic Power Supply PCB Layout Figure 1 – Printed Circuit Board Note: C17 and R14 are not stuffed, C23 and R17 are connected in series and attached to D9 (pin1 and pin2) on the bottom side Page 5 of 26 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-9 Generic PCB for DVD Player using TinySwitch-II February 4, 2004 3 Schematic Figure 2 – Generic schematic showing all options Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com Page 6 of 26 DER-9 Generic PCB for DVD Player using TinySwitch-II February 4, 2004 4 Circuit Description 4.1 Input EMI Filtering C1 and C2 are the bulk capacitors. Together with L1 and L2, they form the EMI filter. TinySwitch-II’s built-in frequency jitter helps achieve low EMI in spite of this very simple EMI filter. C18 is an option for a high voltage ceramic capacitor in case a single electrolytic capacitor is required for the bulk capacitor. 4.2 Primary Clamp Snubber D5, R1, R2, and C3 form the primary clamp snubber to clamp the voltage spike at the Drain pin after TinySwitch-II turn-off. D5 is a 1N4007G, a glass-passivated version of the standard 1N4007, with controlled reverse recovery. Its use, along with R2, improves EMI and efficiency. 4.3 Output filtering C6, C8, C10, C12 and C14 are the main output capacitors. C7, C9, C11 and C13, along with L3, L4, L5 and R8, form second-stage output filters. 4.4 Output Feedback U2, VR1, and R15 form the voltage feedback network. The 5V output voltage setpoint is set by the voltage drops of U2, VR1, and R15. The TinySwitch-II unique feedback scheme, with constant feedback current over line and load changes, means that the current in the zener does not change, thus the voltage drops in U2, VR1, and R15 do not change. This yields tight regulation in spite of the circuit’s simplicity and low cost. 4.5 “DC Switch” J4 is connected to a switch, wherein if it is closed, the 5V output drops to about 1.2V, because the zener ZR1 is essentially shorted out. All the outputs drop to about 1/5th of their normal voltages. During this condition, the load draws very little current. Because of TinySwitch-II’s EcoSmart operation, it draws very little input power -