A Hybrid Control Scheme for a Single-Stage LED Driver With Inherent Power Factor Correction and Low Flicker

This article presents the design and implementation of a hybrid control scheme for a single-stage LED driver. The power stage comprises a class-DE resonant converter coupled with a charge-pump circuit that achieves inherent power factor correction. The end-to-end driver structure incorporates a single half-bridge circuit for switching, resulting in a compact cost-effective solution. The driver operates with zero-voltage switching (ZVS) across the entire load range, allowing for increased switching frequency with high efficiency.Ahybrid control scheme which uses both burst-mode (BM) and frequency-mode (FM) actuation is employed. TheBMactuation uses ON/OFF operation of the switching half-bridge, whereas the FM actuation modulates the switching frequency of the converter, thus regulating the gain of the resonant tank in the power stage. Experimental results demonstrate a power factor (PF) of 0.97, a total harmonic distortion (THD) of 16.8%and a 100-Hz output current flicker content of 6.75%at 30Wof output power. The driver satisfies the requirements set by the IEC 61000-3-2 class-C and IEEE 1789-2015 standards for input current harmonics magnitudes and output current flicker, respectively.