A model of power transistor turn-off dynamics

A theoretical model of npvn power transistor turn-off transients oriented toward circuit analysis is presented. It predicts the collector voltage waveforms under constant collector and reverse base currents in closed-form expressions. In particular, a storage period, a voltage-rise period and their dependence on currents and device parameters are revealed. It also provides a conceptual one-dimensional model for the physical processes of switching turn-off.