A Cost-Effective Zero-Voltage Switching Dual-Output LED Driver

Abstract

—Coupled-inductor (CI) converters are widely used in the light-emitting diode (LED) lighting applications due to several advantages, such as high step-down conversion, reduced switch/diode stress as compared to conventional buck converters. However, the main drawback of CI buck converter is high-voltage spikes during turn-OFF instant due to the leakage inductance of a CI, which leads to switching device failure. Passive clamp cir cuits are used to overcome the leakage inductance problem, but these clamp circuit’s results in reduced efficiency and increased cost. This paper proposes a high step-down zero-voltage switch ing dual-output coupled-inductor buck (ZVS-DOCIB) LEDdriver with dimming control. The proposed LED driver provides vari ous advantages like high step-down conversion, effective recovery of leakage energy, elimination of voltage spikes, reduced switch ing loss due to ZVS operation of both the switching devices, and less switching device count, particularly for multioutput drivers. Also, ZVS operation provides a significant reduction in switching losses, which results in high efficiency. Furthermore, dimming con trol is studied to regulate the average output currents. This paper presents design and analysis of the proposed ZVS-DOCIB con verter. A prototype of the converter has developed and validated experimentally with simulation counterparts.