Impact of Junction Capacitor and Transfer characteristic on EMI prediction

Abstract

While silicon carbide devices miniaturize power electronic devices, they bring more serious EMI problems. This paper proposes a switching model for noise source EMI spectral prediction, which is a key prerequisite for accurate prediction in terms of electronic magnetic interference (EMI). Compared with the asymmetric trapezoidal wave, the modeling of the step-by-step switch with oscillation stage can better reflect the switching characteristics. In addition, the junction capacitance and transfer characteristics have a certain influence on the rise time, fall time and oscillation of the switch, and also affect the noise spectra in different frequency bands. Considering the actual switching process, the effect of junction capacitance and transfer characteristics on the switching oscillation process and the EMI problem of its corresponding frequency band is studied.