Comparative Analysis between the Half Brige Resonant LLC and Buck Converters as the Power Stage of an LED Driver

This paper presents a comparative analysis between the Buck Converter and the LLC Resonant Converter working as LED drivers. These converters are placed after a Power-Factor-Correction (PFC) stage, in order to work as the Power-Control (PC) stage of two-stage LED drivers. The main objective of this study is to evaluate these converters in terms of efficiency, volume and cost using different switching frequencies supplying an LED load of 180W. The methodology used theoretical losses calculation and industrial feedback in order to compare the proposed converters. The Buck converter was evaluated under 33kHz, 60kHz and 100kHz, and the LLC Resonant converter was evaluated under 100kHz, 140kHz, 180kHz, and 220kHz. Both converters were dimmed from 100% to 20%.