A Novel Circuit for Characteristics Measurement of SiC Transistors

Abstract – This paper proposes a novel test circuit for SiC transistors. On-state resistance under practical application conditions is an important characteristic for the device reliability and conduction efficiency of and SiC transistors. In order to measure the on-state resistance in practical applications, high voltage is needed, and high current is also necessary to ignite performance for the devices. A softswitching circuit based on synchronous buck topology is developed in this paper. To provide highvoltage and high-current stresses for the devices without additional spikes and oscillations, a resonant circuit has been introduced. Using the novel circuit technology, soft-switching can be successfully realized for all the switches. Furthermore, in order to achieve accurate measurement of on-state resistance under switching operations, an active clamp circuit is employed. Operation principle and design analysis of the circuit are discussed. The dynamic measurement method is illustrated in detail. Simulation and experiments were carried out to verify the feasibility of the circuit. A special test circuit has been developed and built. Experimental results confirm that the proposed circuit gives a good insight of the devices performance in real applications.