High Step-Down Dual Output Light Emitting Diode Driver

Abstract

A conventional power factor correction (PFC) based light emitting diode (LED) drivers composed of two-stage DC-DC conversions has several drawbacks such as; increased system size due to more component count, less efficiency and complex control etc. The grid powered LED lighting demand for high step-down conversion because the required voltage level of LED light is very less. Thus, this work proposes a one-switch dual-output (OSDO) coupled inductor buck (CIB) LED driver with current auto balancing. OSDO-CIB converter can eliminate most of the drawbacks of conventional counterparts. The proposed OSDO-CIB converter can provide various benefits such as; compact size, high efficiency, less total harmonic distortion (THD), simple control, and significant reduction in device voltage/current rating due to coupled inductors. The converter is designed with discontinuous conduction mode (DCM) of operation in order to achieve in-phase current and voltage, high power factor (PF) and a low THD. This paper mainly emphasized on detailed operating modes and steady-state analysis of proposed converter. Further, proto-type of the converter is built and experimental validations are presented.