A Novel AC/DC Converter Based on Stacked Boost Circuit and Dual-Mode LLC Circuit

In this paper, a AC/DC converter based on stacked Boost circuit and dual-mode LLC circuit is proposed. In the Power Factor Correction (PFC) part, two Boost circuits are stacked to reduce switch voltage stress, also sharing one inductor operating in Boundary Conduction Mode (BCM). In the DC/DC part, a dual-mode LLC circuit is adopted based on two stacked half-bridge structure. The input voltage of LLC resonant tank can double or halve by switching between two operating modes. Hence, the voltage gain of LLC converter can be modified without large operating frequency modulation range. The proposed AC/DC converter can be utilized in widely input voltage variation condition. A 50W prototype is proposed in the laboratory and the experimental results verify the feasibility of the proposed converter.