LLC Resonant DC/DC Converter for LED Headlight Applications with PWM Dimming

This work proposes the use of a high-frequency resonant LLC DC/DC converter with PWM dimming to power an array of LEDs for automotive headlight applications. The resonant tank is designed for frequencies in the hundreds of kilohertz to reduce the size of the passive elements of the converter. The use of a small output filter allows the use of polyester or ceramic capacitors whose lifetime is longer than that of electrolytic capacitors. Thus, a compact size converter can be achieved, with a useful life approximately equal to or greater than that of the array of LEDs.

I. Introduction

Currently, LED lighting systems have almost completely replaced traditional lighting technologies. These LED systems are highly environmentally friendly due to their long lifespan (over 60,000 hours), high luminous efficiency, compact size, dimming capability, and a wide variety of colors. LED lighting applications range from displays and street lighting to signage, general illumination, and automotive headlights [1] [2] [3].