An Integrated Gate Driver with Active Delay Control Method for Series Connected SiC MOSFETs

Series connected SiC MOSFETs technology can apply low rated voltage power device to medium or high voltage applications. However, voltage unbalance problem limits its performance. In this paper, an integrated gate driver with active delay control method for series connected SiC MOSFETs is presented to achieve voltage balance. The main idea is to delay the drive signal for a time period to compensate its deviation between different SiC MOSFET. The delay action is implemented by a delay line IC to adapt the fast switching process of SiC MOSFET. The proposed gate driver provides a closed loop control for series connected SiC MOSFETs. It can effectively balance the voltage without slowing down the switching speed or inducing extra losses, and the effectiveness of the proposed gate driver has been verified by experimental results.