DER-340: 750mA @ 54V Max, 90 ~ 300VAC In

The document describes a non-isolated high power factor (PF) LED driver designed to drive a nominal LED string voltage of 54 V at 750 mA from an input voltage range of 90 VAC to 300 VAC. The LED driver utilizes the LNK419EG from the LinkSwitch-PH family of ICs.

The topology is a single-stage non-isolated buck converter that meets the high efficiency requirements for this design. Good line and load output current regulation is achieved by directly sensing the output current and using shunt regulator for closed-loop feedback control.

High power factor and low THD is achieved by employing the LinkSwitch-PH IC which also provides a sophisticated range of protection features including auto-restart to prevent damage in the event of open control loop or during output short-circuit. Line overvoltage protection provides extended line fault and surge withstand. Output overvoltage protects the supply should the load be disconnected. Accurate hysteretic thermal shutdown ensures safe PCB temperatures under all conditions.

This document contains the LED driver specification, schematic, PCB diagram, bill of materials, transformer documentation and typical performance characteristics.