DER-338 - Input-only low-voltage, ultra-thin, T8, isolated, 23 W, power factor corrected (PF >0.98) LED driver designed using LYTSwitch LYT4215E

This document describes the design of an ultra-thin T8 (component height <10 mm), isolated, high power factor (PF) LED driver that operates at a nominal voltage of 50 V over an input voltage range of 90 VAC to 135 VAC. The LED string lights provide 430 mA drive. This LED driver uses the LYT4215E device in the LYTSwitch series IC. The main objectives of this design are to: • Fit into a narrow (<20 mm), low component height (<10 mm) T8 lamp housing • Withstand 1 kV differential mode surges The topology used is a single stage, with Power factor corrected, continuous conduction mode flyback topology that meets high efficiency, high power factor, low THD, isolation, low component count, and tight space requirements. LYTSwitch IC can also provide various complex protection functions, including automatic restart under loop open or output short-circuit conditions. This device can achieve high power factor and low THD. This document contains LED driver specifications, circuit schematics, PCB design drawings, bill of materials, transformer specification files and typical performance characteristics.