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

The automotive industry is moving toward 42 volt to meet the more electric needs. Several dual voltage (42 and 14 volt) architectures have been proposed for the transition and accommodation of 14-volt loads. A DC-DC converter that connects the 42 and 14 volt architectures is one key device in any dual voltage architecture. This paper presents a compact, efficient, magnetic-less bi-directional DC-DC converter for dual voltage (42/14 Volt) 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 (EMI), and have low cost by using low-voltage metal oxide field effect transistors (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.