The fast-switching of the wide-bandgap (WBG) devices leads to great challenges to the gate driver design. The gate drivers are required to have strong immunity to the electromagnetic interference (EMI) noise. In a half bridge structure, the Kelvin source of the high side switch is a jumping node with high dv/dt rate, inducing common-mode (CM) noise current to flow on the gate driver PCB. Gate drivers for modern power electronic converters have complex design to achieve sophisticated functionalities, some even have integrated current sensors for fault detection. Meanwhile, gate drivers are one of the components that are most susceptible to the EMI noise and are prone to have false triggering issues. The high noise-immunity design for gate driver is of vital importance. Various approaches were shown in prior art to mitigate the CM noise on gate drivers. This paper discusses the CM current propagation on gate drivers as part of the converter-level EMI propagation model and presents a novel structure that utilizes the integrated current sensors to form a balanced Wheatstone bridge for further CM noise mitigation.
