Crosstalk Analysis and Suppression for a Closed-Loop Active IGBT Gate Driver

This paper analyzes the crosstalk issues for a closed-loop active insulated gate bipolar transistor (IGBT) gate driver (AGD) based on di/dt and dv/dt detection and presents a crosstalk suppression (CTS) circuit. Closed-loop active gate drivers for IGBTs are beneficial in switching transient control by generating extra gate control signals to regulate the gate drive voltage or current with di/dt and dv/dt feedback. AGDs achieve the compensation of the IGBT nonlinearities and are independent of operating points. In a phase-leg configuration, however, AGDs produce additional crosstalk interference besides that due to reverse transfer capacitance. These two kinds of crosstalk interferences together lead to an oscillation in the IGBT gate voltage, and then a shoot-through fault may occur. An equivalent circuit model of the feedback circuit is presented to analyze and evaluate the crosstalk issues. The design and realization of a CTS circuit are presented to eliminate the crosstalk and extra gate drive losses caused by crosstalk. The experimental results substantiate the validity of the theoretical crosstalk analysis and the effectiveness of the proposed CTS circuit.