RDK-142

Reference Design Report for a 35 W Power TM Title Supply Using TOPSwitch -HX TOP258PN 90 VAC to 265 VAC Input Specification 5 V, 2.2 A and 12 V, 2 A Outputs Application LCD Monitor Author Applications Engineering Department Document RDR-142 Number Date August 07, 2014 Revision 1.3 Summary and Features Low cost, low component count, high efficiency Delivers 35 W at 50 C ambient without requiring an external heat sink Meets output cross regulation requirements without linear regulators TM EcoSmart meets requirements for low no-load and standby power consumption 0.42 W output power for <1 W input No-load power consumption < 300 mW at 230 VAC >82% full load efficiency Integrated safety/reliability features Accurate, auto-recovering, hysteretic thermal shutdown function maintains safe PCB temperatures under all conditions Auto-restart protects against output short-circuits and open feedback loops Output OVP protection configurable for latching or self-recovering Input UV prevents power up / power down output glitches Meets EN55022 and CISPR-22 Class B conducted EMI with >10 dBV margin 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 RDR-142 35 W, TOP258PN Dual Output Supply 07-Aug-14 Table of Contents 1 Introduction ................................................................................................................. 4 2 Power Supply Specification ........................................................................................ 5 3 Schematic ................................................................................................................... 6 4 Circuit Description ...................................................................................................... 7 4.1 Input EMI Filtering ............................................................................................... 7 4.2 TOPSwitch-HX Primary ....................................................................................... 7 4.3 Output Rectification ............................................................................................. 8 4.4 Output Feedback ................................................................................................. 9 4.5 PCB Layout ....................................................................................................... 10 5 Bill of Materials ......................................................................................................... 11 6 Transformer Specification ......................................................................................... 13 6.1 Electrical Diagram ............................................................................................. 13 6.2 Electrical Specifications ..................................................................................... 13 6.3 Materials ............................................................................................................ 13 6.4 Transformer Build Diagram ............................................................................... 14 6.5 Transformer Construction .................................................................................. 15 7 Transformer Design Spreadsheet ............................................................................. 16 8 Performance Data .................................................................................................... 20 8.1 Efficiency ........................................................................................................... 20 8.1.1 Active Mode CEC Measurement Data........................................................ 21 8.2 No-Load Input Power ........................................................................................ 22 8.3 Available Standby Output Power ....................................................................... 23 9 Regulation ................................................................................................................ 24 9.1.1 Load ........................................................................................................... 24 9.1.2 Line ............................................................................................................ 25 9.1.3 Cross Regulation Matrix ............................................................................. 26 10 Thermal Performance ........................................................................................... 27 11 Waveforms ............................................................................................................ 29 11.1 Drain Voltage and Current, Normal Operation ................................................... 29 11.2 Output Voltage Start-up Profile .......................................................................... 29 11.3 Drain Voltage and Current Start-up Profile ........................................................ 31 11.4 Load Transient Response (75% to 100% Load Step) ....................................... 32 11.5 Output Overvoltage Protection .......................................................................... 34 11.6 Output Ripple Measurements ............................................................................ 35 11.6.1 Ripple Measurement Technique ................................................................ 35 11.6.2 Measurement Results ................................................................................ 36 12 Line Surge............................................................................................................. 38 13 Control Loop Measurements ................................................................................. 39 13.1 90 VAC Maximum Load..................................................................................... 39 13.2 265 VAC Maximum Load ................................................................................... 40 14 Conducted EMI ..................................................................................................... 41 15 Revision History .................................................................................................... 42 Important Note: Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com Page 2 of 43