Experimental investigation of monolithic cascode devices in inverter leg applications

In this paper an experimental investigation of the performances of a cascode monolithic device in a half bridge configuration is carried out, and a comparison is performed in the same converter in case IGBT devices are used. The device behavior during the reverse current conduction in the inverter leg is investigated and discussed. The experimental evidence shows that the cascode suffers the same problem of bipolar transistors in inverter leg applications, i.e. the reverse conduction through the base-collector junction as freewheeling diode. Different circuit solutions are analyzed aiming to eliminate this undesired reverse current conduction, and a good topology is appointed.