An Electrolytic Capacitor-Less AC-DC LED Driver with a Low Power Processing Auxiliary Circuit and Ceramic Capacitors for Ripple Power Decoupling

Abstract

Traditional ac-dc LED drivers include a large electrolytic capacitor to decouple the double-line frequency ripple power from the utility grid, which shortens the lifespan of LED lamps. This paper presents an electrolytic capacitor-less ac-dc LED driver with a low power processing auxiliary circuit and ceramic capacitors decoupling the ripple power. In this structure, the redundant power processed by the auxiliary circuit is lower and fewer components are used, comparing with existing similar designs. In addition, the ceramic capacitors that are used as the energy storage have higher energy density and lower cost. The capacitance drift of ceramic capacitors is modeled and analyzed, and the parameter design for the ceramic capacitor bank is given. Experiments on a prototype are carried out to verify the performance and design of the proposed LED driver.