Digital Active Gate Driving System for Paralleled SiC MOSFETs with Closed-loop Current Balancing Control

Parallel connection of multiple SiC MOSFETs is often adopted to increase converter power rating. However, due to mismatches in the circuit layout parasitic or differences in the device's parameters, achieving a balanced current sharing between the paralleled devices poses a severe challenge. This paper proposes an active gate driving system integrated with a digital closed-loop control method. This solution has the advantages of being independent with the SiC device's parameters variation and adaptive to load variations. Experimental results prove that the proposed closed-loop control can successfully achieve correct dynamic and static current sharing acting on the adjustable parameters of the active gate driver, such as the on-state voltage and rising edge delay.