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 circuits 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 switching dual-output coupled-inductor buck (ZVS-DOCIB) LED driver with dimming control. The proposed LED driver provides various advantages like high step-down conversion, effective recovery of leakage energy, elimination of voltage spikes, reduced switching 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 control is studied to regulate the average output currents. This paper presents design and analysis of the proposed ZVS-DOCIB converter. A prototype of the converter has developed and validated experimentally with simulation counterparts.