Balancing Unequal Temperature Distributions of Parallel-Connected SiC MOSFETs Using an Intelligent Gate Driver

Abstract

In this paper, an intelligent gate driver for parallel-connected silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) is presented. Commercial gate drivers often slow down the switching event to compensate for unevenly distributed switching losses in parallel-connected MOSFETs. With the use of the presented gate driver, it is possible to match the temperature of parallel-connected MOSFETs even with low gate resistances. To achieve this, the gate signals of the parallel-connected MOSFETs are delayed in the nano second range in order to influence the current distribution during the switching events. This allows fast switching operations without the need for derating the switching cell. The measurement results are compared with a push-pull gate driver. It is shown that the temperature difference of two MOSFETs connected in parallel can be reduced from 8K when using a push-pull gate driver to 0K when using the presented gate driver. The gate driver thus makes it possible to fully exploit the potential of SiC MOSFETs and to increase the power density of power electronics converters.