A Power Converter with Pulse-Level-Modulation Control for Driving High Brightness LEDs

High brightness (HB) LED provides higher efficacy and reliability over incandescent light bulb. Different from incandescent light bulb, HB LED needs to be driven by accurate constant current for consistent brightness and color-temperature light emission. With a novel method pulse-level-modulation (PLM) control applied on conventional switched-mode power stage, a more robust, power-efficient and accurate power converter for driving HB LEDs is realized. This paper includes the step-by-step design of the realized power converter. Demonstration of the circuit driving a string of 0.35A HB LEDs is presented.