Fully automated measurement set-up for ultra-fast recovery diode testing

Often data sheets provide only poor information about the recovery behavior of ultra-fast diodes. On the other hand, existing diode models do not predict the real characteristic for all diodes. Nevertheless, due to its importance, this behavior needs to be known and therefore measured. For this purpose, a fully automated measurement set-up for determining the reverse recovery characteristic of ultra-fast diodes in an accurate manner was designed and is described here. All the data obtained is immediately transferred into MATLAB and therefore available for further calculation, model building and model validation. Since the whole set-up is automated, a complete field of variations in the reverse voltage, the forward current, the temperature, and the di/dt can be easily applied to the tested diode. Hence, a lot of information can be obtained effortlessly. This uncomplicated methodology makes it readily available for circuit designers, allowing them to predict the contribution of the reverse recovery of rectifiers to the total losses more accurately. In addition, a real comparison of different diodes at many operation points is made possible.