Simple and Affordable Method for Fast Transient Measurements of SiC Devices

The measurement of fast voltage and current transients of Silicon Carbide (SiC) devices requires high bandwidth (BW) probes. Commercially available voltage and current probes can be expensive, and, in addition, the delay introduced by them must be compensated to achieve a proper time alignment (de-skew). Determining this de-skewing value is not a trivial task. In this paper, a simple and affordable measurement method is presented for the simultaneous measurement of the voltage and current transients of SiC devices. The voltage is measured by means of a high BW RC attenuator, while the current is estimated from the voltage drop in the stray inductance of the switching loop. Since both voltages are measured with two equal and matched high BW passive voltage probes, there is no need to apply any de-skew. This is one of the most important advantages of the method. The presented method is experimentally evaluated and used for the estimation of energy switching losses in the tested SiC-mosfet.