Application-close Study of a SiC JFET Cascode Switching Characteristic under dv/dt-Limitations

Inhalt:
The cascoded Silicon Carbide (SiC) JFET represents an alternative to the SiC MOSFET in terms of fast switching and low-loss conduction. However, driving cascode devices is not particularly well known. Conventional dv/dt control methods, such as varying the external gate drive resistor, exhibit little impact in a cascode configuration. This work explores alternative control parameters in hard-switching setups where the cascode is used simultaneously as a switching and freewheeling device. Instead of a discrete structure, a stack cascode is inserted into the inverter topology of a MiniSKiiP(r) module. The switching characteristic and handling of parasitic effects is examined. As a possible replacement for the state-of-the-art IGBT, the losses in inverter operation are compared and the benefits of the well-controlled cascode are shown.