DER-740 - 29 W high power factor, isolated flyback LED driver with 3-in-1 and DALI dimming

This engineering report describes an isolated flyback LED driver compatible with 3-in-1 dimming and DALI dimming. It is designed to drive a nominal 36 V LED voltage string at 800 mA over an input voltage range of 180 VAC to 265 VAC. The LED driver uses LYT6067C in the LYTSwitch-6 series of devices. The DER-740 is a high line input flyback converter design with added switching valley fill PFC circuitry. Through the PFC circuit, the design meets the high power factor requirements in LED lighting applications while reducing losses through direct energy transfer. The main design goals are to achieve high efficiency, high power factor within the input voltage range, and three-in-one dimming and DALI dimming range from 0% to 100%. This document contains power supply specifications, schematics, bill of materials, transformer documentation, printed circuit board layout, and performance data.