A Single-stage Single-switch LED Driver Based on Integrated Buck-boost Circuit and Class E Converter

A single-stage single-switch LED driver is proposed in this paper. The topoloy of the converter is formed by integrating buck-boost and Class E circuit by sharing one switch device, which can greatly reduce the cost and improve the reliability of the system. To realize the power factor correction (PFC) function, the buck-boost circuit works in discontinuous conduction mode (DCM). Since the soft switching characteristics of the Class E resonant circuit are not affected by the switch integration, the converter is with low switch losses and high efficiency. Analytical results and design considerations at 100 kHz are presented, along with a 100W prototype which efficiency is as high as 90.8% in full load state under 110VAC input is proposed to verify the theoretical analysis.