Sunano (China)

The MOSFET is one of the most widely used power devices in mid-voltage applications, offering advantages such as fast switching, high power density, and miniaturized power electronics converters. However, rapid switching transients also introduce high-frequency oscillations, which pose a significant challenge and require mitigation with minimal system modifications. T his p aper p resents a n ovel t ransfer function-based methodology for analytically modeling MOSFET switching behavior, enabling precise prediction of drain current and voltage transitions under controlled gate current. The transfer function-based analysis reveals that the drain current oscillation is dependent on the change of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">di_D</i>/<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dt</i> at its peak magnitude, regardless of other time intervals during the switching transient. A quadratic equation is obtained to comprehensively describe the behavior of increasing drain current, and a linear function for the drain-source voltage. The proposed gate current profile is implemented via a fully integrated digital active gate driver IC that reduces oscillations by 32 % without additional switching losses. Unlike previous works that primarily rely on empirical gate driver design, the fundamental transfer function-based analytical model introduced in this paper directly links the gate current profile to MOSFET oscillation behavior. Based on this model, a three-step gate current profile is systematically constructed, which is straightforward to implement and adapt using a fully digital, programmable AGD IC. This enables oscillation suppression and loss minimization to be achieved with a practical, integrated solution beyond conventional analog-based approaches.