| 摘要 |
PURPOSE:To obtain the titled device with small size, high speed and high dielectric strength by turning on other semiconductor switching element into the ON-state before one semiconductor switching element is turned off by a gate signal so as to commutate a load current flowing to the one semiconductor switching element to the other semiconductor switching element. CONSTITUTION:A GTO is used as a turn on/off switching element SW1 and a bipolar transistor (BTRS) is used as a turn-off switching element SW2. As a forward base current iB of the BTRS increases, the collector current iTRS of the BTRS increases. The n-channel base and the p-channel base junction and the p-channel base and the n-channel emitter junction of the GTO start recovering at a time tS1 and the anode voltage vA (voltage between A and K in figure) starts increasing. The collector current iTRS is increased rapidly from the point of time and the relation of iTRS=iL is caused after a time tf1. Thus, the anode current iGTO=iL-iTRS of the GTO is decreased rapidly and zero at a point of time (tS1-tf1). The relation of VA approx.<30V exists at this point of time and the turn-on loss in the GTO is reduced remarkably. |
