Accurate MOSFET Modeling Approach with Equivalent Series Resistance of Output Capacitance for Simulating Turn-OFF Oscillation

Abstract

High-speed switching of power semiconductors facilitates the achievement of high efficient and compact power converters. On the other hand, a high dv/dt switching easily causes a damped oscillation, which leads to increase power loss and EMI noise. Hence, the device models to simulate the oscillation are necessary for theoretical understandings. However, conventional MOSFET models often lack an equivalent series resistance of output capacitance, which is called <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$R_{\text{oss}}$</tex> . This paper proposes a MOSFET simulation model, including the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$R_{\text{oss}}$</tex> which has the potential to damp a turn-off oscillation waveform. Extracting an <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$R_{\text{oss}}$</tex> value by using an impedance analyzer, circuit simulation and experimental verifications are performed to validate the MOSFET simulation model. Compared to a conventional modeling approach, the proposed model significantly suppresses a deviation in the damping factor of oscillation waveform.