RDK-669 Power Integrations

Reference Design Report for a 5 W Adapter Title TM Using LinkSwitch -CV LNK625DG Specification Input: 85 VAC 265 VAC Output: 5 V / 1 A Application Adapter Author Applications Engineering Department Document RDR-669 Number Date June 23, 2020 Revision 1.4 Summary and Features Low parts count solution Auto-restart output short-circuit, open-loop and over-temperature protection Primary side regulated Meets EN55022 EMI 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.power.com. Power Integrations 5245 Hellyer Avenue, San Jose, CA 95138 USA. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.power.com RDR-669 5W Universal Adapter Using LNK625DG 23-Jun-20 Table of Contents 1 Introduction ................................................................................................................ 4 2 Power Supply Specification ....................................................................................... 5 3 Schematic .................................................................................................................. 6 4 Circuit Description ...................................................................................................... 7 4.1 Input and EMI Filtering ......................................................................................... 7 4.2 LinkSwitch-CV Device .......................................................................................... 7 4.3 Primary Circuit ...................................................................................................... 7 4.4 Output Rectification .............................................................................................. 8 4.5 Feedback Winding ................................................................................................ 8 5 PCB Layout ................................................................................................................. 9 6 Bill of Materials ........................................................................................................ 10 7 Transformer Specification ........................................................................................ 11 7.1 Electrical Diagram .............................................................................................. 11 7.2 Mechanical Diagram ........................................................................................... 11 7.3 Material List ........................................................................................................ 12 7.4 Electrical Test Specifications .............................................................................. 12 7.5 Transformer Winding Illustrations ....................................................................... 13 8 Performance Data .................................................................................................... 16 8.1 Full Load Efficiency vs. Input Line Voltage (at PCB) .......................................... 16 8.2 Efficiency vs. Load (at PCB) ............................................................................... 17 8.3 Average Efficiency .............................................................................................. 18 8.3.1 115 VAC / 60 Hz ........................................................................................ 18 8.3.2 230 VAC / 50 Hz ........................................................................................ 18 8.4 No-Load Input Power .......................................................................................... 19 8.5 Line and Load Regulation ................................................................................... 20 8.5.1 Line Regulation at Full Load (at PCB) ........................................................ 20 8.5.2 Load Regulation (at PCB) .......................................................................... 21 9 Waveforms .............................................................................................................. 22 9.1 Drain Voltage and Current, Normal Operation Full Load .................................... 22 9.2 Drain Voltage and Current Start-up Profile ......................................................... 23 9.3 Output Diode Reverse Voltage ........................................................................... 24 9.4 Output Rise Time ................................................................................................ 25 9.5 Turn On Delay .................................................................................................... 26 9.6 Output Ripple Measurements ............................................................................. 27 9.6.1 Ripple Measurement Technique ................................................................ 27 9.6.2 Output Ripple Measurements ..................................................................... 28 10 Temperature Measurements ................................................................................... 29 10.1 Thermal Performance ...................................................................................... 30 10.1.1 Thermal Performance at 85 VAC ............................................................... 30 10.1.2 Thermal Performance at 265 VAC ............................................................. 32 10.1.3 Thermal Performance at 50 C ................................................................... 34 10.1.4 Thermal Performance at 40 C ................................................................... 36 10.2 Thermal Shutdown and Recovery ................................................................... 36 10.2.1 Shutdown and Recovery Temperature at 85 VAC, 50 C Ambient............. 36 Power Integrations, Inc. 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