A magnetic-less DC-DC converter for dual-voltage automotive systems

The automotive industry is moving toward 42 V to meet more electrical needs. Several dual-voltage (42 and 14 V) architectures have been proposed for the transition and accommodation of 14-V loads. A DC-DC converter that connects the 42 and 14 V is one key device in any dual-voltage architecture. This paper presents a compact, efficient, magnetic-less bidirectional DC-DC converter for dual-voltage (42/14 V) automotive systems. The DC-DC converter is based on the generalized multilevel converter topology having the ability to balance battery voltages, emit zero or low electromagnetic interference, and have low cost by using low-voltage MOSFETs. The main circuit of the DC-DC converter is analyzed and its control scheme is presented in the paper. A self-powered gate drive circuit is developed for the DC-DC converter to reduce costs, signal connections, and circuit complexity. A prototype has been built and experimental results are presented.