Output-inductor-less active clamp forward converter employing current boost-up technique for high efficiency adaptor

Abstract

Nowadays, power supply market needs the adaptor power supply with high power density and high efficiency. To meet this trend, many researches are conducted in power companies. Especially, converters without output inductor hold more attraction, because they can be achieved for high power density. There are two types of converter topologies which have no output-inductor for DC/DC converter, active clamp flyback converter and output-inductor-less converter. However, these two types of converters have critical problems. In active clamp flyback converter, DC offset current which degraded transformer utilization is existed and makes transformer bulky. It cause low power density. Output-inductor-less active clamp forward converter has high RMS value of current which cause heat problem. This paper proposes an output-inductor-less active clamp forward converter employing current boost-up technique for high efficiency adaptor. By applying the proposed current boost-up technique, the proposed converter has low conduction loss and low voltage ringing of the secondary rectifier. This paper presents the operational principle, design consideration, the analysis of the proposed converter. Experimental results are demonstrated to verify the feasibility and advantages of the proposed converter.