Characterization Method of SiC-JFET Interelectrode Capacitances in Linear Region

摘要

In order to study switching waveforms of a SiC-JFET, its interelectrode capacitances evolution is necessary when the power device is in linear region. In this paper, the reverse transfer capacitance is at first characterized by the multiple-current-probe method and afterwards validated by the measurement with an impedance analyzer. The output capacitance is measured by the same method and compared with the single-pulse characterization, which shows a huge increase of the apparent capacitance values in linear region. The influence of the power transistor internal gate resistor is thus studied, revealing the interelectrode capacitances measurement difficulties when the power device is in linear region. The characterization results are allowed to finely model the power transistor of which the switching behaviors are validated with the measurement in a buck converter.