A snubber design tool for p-n junction reverse recovery using a more accurate simulation of the reverse recovery waveform

A computer simulation of the reverse-recovery current waveform of a p-n junction undergoing forced commutation is presented. It is found that a far better simulation is obtained by using the sech function to model the recovery current than by using the common exponential function. Published maximum values of recovery current, recovery time, and snap factor can be used to determine the constants of the sech function. The proposed model and predicted junction response are compared with laboratory measurements of devices of various technologies. The application of the simulation to free-wheel diodes and GTO (gate-turn-off) snubber diodes is illustrated.<
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