DER-318: 430mA @ 50V Max, 185 ~ 265VAC in

The document describes a low profile T8 (<10 mm component height), isolated, high power factor (PF) LED driver designed to drive a nominal LED string voltage of 50 V at 430 mA from an input voltage range of 185 VAC to 265 VAC. The LED driver utilizes the LNK419EG from the LinkSwitch-PH family of ICs.

Key Goals for this design were:
• Fit into narrow (<20 mm, component height <10 mm) T8 lamp enclosure
• Meet Class C harmonic limit to allow paralleling two LED drivers (>25 W) in a single fixture where Class C is then required
• Pass 1 kV differential surge

The topology is a single-stage, power factor corrected continuous conduction mode flyback that meets high efficiency, high power factor, low THD, isolation, low component count, and meets stringent space requirements.

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 for open control loop and output short-circuit conditions.

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