A New Proportional Base Driver Technique for Minimizing Driver Loss of SiC BJT

The SiC BJT offers an attractive alternative to the more popular SiC MOSFETs. However, large power consumption of its base driver hampers its widespread in the market. In this paper, we propose a new proportional base driver to minimize its base driver's power consumption in the conduction state. It uses Si BJT to provide adaptive base current for the SiC BJT when the collector current varies with the load. Theoretical formulation predicts that it can provide an ideal base current for the SiC BJT with minimum base driver loss by means of optimum selection of the Si BJT. The proportional base drive method is validated in a boost converter where varying duty cycles are used to emulate the variation of load. The experimental results show that the power consumption of the proposed proportional base driver is reduced by 90.1% compared to the conventional dual source base driver in conduction state when collector current is 1.72A.