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

摘要

A computer simulation of the inverse recovery current waveform of a p-n junction undergoing forced commutation is presented. A far better simulation is obtained by using the sech (hyperbolic secant) function to model the recovery current as compared with the commonly used exponential function. Published maximum values of the recovery current, recovery time, and snap factor can be used to determine the constants of the sech function. The proposed model and its response are compared with laboratory measurements of devices of various technologies. The application of the simulation to free-wheel diodes and GTO snubber diodes is illustrated.