AN 201611 PL83 003 27 W 12 V 5 V SMPS demo board with ICE5QR1680AG About this document Scope and purpose This document is an engineering report that describes a universal-input 27 W 12 V and 5 V off-line flyback th converter using the newest 5 generation Infineon QR CoolSET ICE5QR1680AG. It offers high-efficiency, low- standby power with selectable entry and exit standby power options, a wider V CC operating range with fast start-up, robust line protection with input Over Voltage Protection (OVP), and brownout and various modes of protection for a highly reliable system. This demo board is designed for users who wish to evaluate the performance of ICE5QR1680AG and its ease of use. Intended audience This document is intended for power-supply design/application engineers, students, etc., who wish to design low-cost and highly reliable systems of off-line SMPS, such as auxiliary power supplies for white goods, PCs, servers and TVs, or enclosed adapters for blu-ray players, set-top boxes, games consoles, etc. Table of contents About this document ....................................................................................................................... 1 Table of contents ............................................................................................................................ 1 1 Abstract ........................................................................................................................ 3 2 Demo board .................................................................................................................. 4 3 Specifications of the demo board .................................................................................... 5 4 Circuit description ......................................................................................................... 6 4.1 Line input ................................................................................................................................................. 6 4.2 Start-up .................................................................................................................................................... 6 4.3 Integrated MOSFET and PWM control .................................................................................................... 6 4.4 RCD clamper circuit ................................................................................................................................. 6 4.5 Output stage ............................................................................................................................................ 6 4.6 Feedback loop ......................................................................................................................................... 6 4.7 Primary side peak-current control ......................................................................................................... 6 4.8 Digital frequency reduction .................................................................................................................... 7 4.9 Active Burst Mode (ABM) ......................................................................................................................... 7 5 Protection features ........................................................................................................ 8 6 Circuit diagram.............................................................................................................. 9 7 PCB layout ................................................................................................................... 10 7.1 Top side ................................................................................................................................................. 10 7.2 Bottom side ........................................................................................................................................... 10 8 Bill of materials ............................................................................................................ 11 9 Transformer construction .............................................................................................. 13 10 Test results .................................................................................................................. 14 Application Note Please read the Important Notice and Warnings at the end of this document Revision 1.0 www.infineon.com 2017-06-15 27 W 12 V 5 V SMPS demo board with ICE5QR1680AG Abstract 10.1 Efficiency, regulation and output ripple .............................................................................................. 14 10.2 Standby power ...................................................................................................................................... 15 10.3 Line regulation ...................................................................................................................................... 16 10.4 Load regulation ..................................................................................................................................... 17 10.5 Maximum input power .......................................................................................................................... 18 10.6 ESD immunity (EN 61000-4-2) ............................................................................................................... 18 10.7 Surge immunity (EN 61000-4-5) ............................................................................................................ 18 10.8 Conducted emissions (EN 55022 class B) ............................................................................................. 18 10.9 Thermal measurement ......................................................................................................................... 21 11 Waveforms and scope plots ........................................................................................... 22 11.1 Start-up at low/high AC-line input voltage with maximum load ........................................................ 22 11.2 Soft-start ................................................................................................................................................ 22 11.3 Drain and CS voltage at maximum load ............................................................................................... 23 11.4 Zero crossing point during normal operation ...................................................................................... 23 11.5 Load transient response (dynamic load from 10% to 100%) .............................................................. 24 11.6 Output ripple voltage at maximum load .............................................................................................. 24 11.7 Output ripple voltage at ABM 1 W load ................................................................................................ 25 11.8 Entering ABM ......................................................................................................................................... 25 11.9 During ABM ............................................................................................................................................ 26 11.10 Leaving ABM .......................................................................................................................................... 26 11.11 Line OVP (non-switch auto restart) ...................................................................................................... 27 11.12 Brownout protection (non-switch auto restart) .................................................................................. 27 11.13 V OVP (odd-skip auto restart) ............................................................................................................. 28 CC 11.14 V under-voltage protection (auto restart) ......................................................................................... 28 CC 11.15 Over-load protection (odd-skip auto restart) ...................................................................................... 29 11.16 Output OVP (odd-skip auto restart)...................................................................................................... 29 11.17 V short-to-GND protection ................................................................................................................. 30 CC 12 References ................................................................................................................... 31 Revision history ............................................................................................................................ 31 Application Note 2 Revision 1.0 2017-06-15