RDK-469

Reference Design Report for a Dual Output TM Title 20 W Power Supply Using InnoSwitch -EP INN2605K 85 VAC 264 VAC Input Specification 12 V, 1.5 A and 5 V, 0.5 A Outputs Application Embedded Power Supply Author Applications Engineering Department Document RDR-469 Number Date February 4, 2016 Revision 1.3 Summary and Features InnoSwitch-EP - industry first AC/DC ICs with isolated, safety rated integrated feedback Built in synchronous rectification for >87% efficiency All the benefits of secondary side control with the simplicity of primary side regulation Insensitive to transformer variation Extremely fast transient response independent of load timing Meets output cross regulation requirements without linear regulators Primary sensed output overvoltage protection (OVP) eliminates optocoupler for fault protection Accurate thermal protection with hysteretic shutdown Input voltage monitor with accurate brown-in/brown-out and overvoltage protection PATENT INFORMATION The products and applications illustrated herein (including transformer construction and circuits external to the products) 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 grants its customers a license under certain patent rights as set forth at <RDR-469 20 W InnoSwitch-EP Dual Output Supply 04-Feb-16 Table of Contents 1 Introduction ......................................................................................................... 4 2 Power Supply Specification ................................................................................... 6 3 Schematic ............................................................................................................ 7 4 Circuit Description ................................................................................................ 8 4.1 Input EMI Filtering ......................................................................................... 8 4.2 InnoSwitch-EP Primary ................................................................................... 8 4.3 InnoSwitch-EP IC Secondary .......................................................................... 8 5 PCB Layout ........................................................................................................ 10 6 Bill of Materials .................................................................................................. 12 7 Transformer (T1) Specification ............................................................................ 14 7.1 Electrical Diagram ........................................................................................ 14 7.2 Electrical Specifications ................................................................................ 14 7.3 Material List ................................................................................................ 14 7.4 Transformer Build Diagram .......................................................................... 15 7.5 Winding Instructions .................................................................................... 15 7.6 Winding Illustrations .................................................................................... 16 8 15 mH Common Mode Choke (L1) Specification ................................................... 21 8.1 Electrical Diagram ........................................................................................ 21 8.2 Electrical Specifications ................................................................................ 21 8.3 Material List ................................................................................................ 21 8.4 Winding Instructions .................................................................................... 21 8.5 Illustrations ................................................................................................. 21 9 90 H Common Mode Choke (L2) Specification .................................................... 22 9.1 Electrical Diagram ........................................................................................ 22 9.2 Electrical Specifications ................................................................................ 22 9.3 Material List ................................................................................................ 22 9.4 Illustrations ................................................................................................. 22 10 Transformer Design Spreadsheet ..................................................................... 23 11 Performance Data ........................................................................................... 26 11.1 Full Load Efficiency vs. Line .......................................................................... 26 11.2 Efficiency vs. Load (0 A 1.5 A on 12 V, Full Load on 5 V) ............................. 27 11.3 Efficiency vs. Load (0 A 1.5 A on 12 V, No-Load on 5 V) .............................. 28 11.4 No-Load Input Power ................................................................................... 29 11.5 5 V Output Power with Low Input Power (No-Load on 12 V) .......................... 30 11.6 Line and Load Regulation ............................................................................. 31 11.6.1 Line Regulation (Full load) ..................................................................... 31 11.6.2 Cross Load Regulation ........................................................................... 32 12 Thermal Performance ...................................................................................... 36 12.1 85 VAC........................................................................................................ 36 12.2 110 VAC ...................................................................................................... 37 12.3 230 VAC ...................................................................................................... 38 12.4 265 VAC ...................................................................................................... 39 Power Integrations, Inc. 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