Power losses estimation in a GaN-based synchronous Buck LED driver

This paper presents the theoretical and experimental power losses analysis of a Gallium Nitride (GaN)-based Synchronous Buck converter, which employs two enhancement mode (e-GaN) transistors in a half-bridge configuration. This topology is used as the Power Control (PC) stage of a two-stage LED driver. A theoretical method for power loss estimation and distribution is presented. An 180W converter is built and tested experimentally to validate the proposed methodology. Practical efficiency reaches 97%, and the percentage error between the estimated and the experimental efficiency is 0.064%. The efficiency curve, from 10% to 100% of the nominal load is also presented.