Pitfalls and their Avoidability in the Double-Pulse Test

Abstract:
Double-pulse tests are a common method to characterize the switching behavior of power semiconductors. However, there are many pitfalls when performing them. Especially the higher transients typically occuring with wide-bandgap semiconductors make the double-pulse test much more challenging as compared to setups with normal silicon semiconductors. This paper gives an overview of error sources and their troubleshooting. Using before and after comparisons, it is explained how faulty current sensors can be identified and the parasitic capacitance of the load-current-forming inductor can be decoupled from the switching process for clean switching. Furthermore it is shown, how a suitable voltage probe and oscilloscope can be selected for the given application. The theory of switching behavior will also be discussed in order to provide the basis for the experiments.