High power factor integrated buck-boost flyback converter driving multiple outputs

This paper proposes an integrated single-stage ac-to-dc light-emitting-diode (LED) driver circuit. A buck-boost power factor (PF) corrector is integrated with a flyback converter. A recycling path is built to recover the inductive leakage energy. The proposed circuit provides high PF and low total harmonic distortion. It also provides high conversion efficiency and low switching voltage spikes. An added feature of the integrated buck-boost converter is that, it provides multiple outputs by providing multiple windings in the secondary.