A comparative study between two single-stage LED drivers: A sole converter versus an integrated topology

This work proposes a comparison between two different approaches for LED driving, based on the Ćuk converter operating in discontinuous conduction mode and an integrated SEPIC Buck-Boost converter. A brief analysis of each converter is carried out and a design methodology is presented, focused in reducing output filtering capacitance, still achieving acceptable current ripple on the output and eliminating the need for electrolytic capacitors. The LED photometric performance under different ripple conditions has been analyzed to aid the design methodology in order to optimize output current ripple selection and capacitor reduction. The control strategy for each converter was presented and validated experimentally. Experimental results were obtained for both converters from two prototypes feeding 56 series-associated high-power LEDs from 220 VAC-60 Hz mains.