Power semiconductor switching off method for switch protection - has discharge of switch capacitance before turn off only in overload conditions

摘要

In operation a control voltage turns on the power semiconductor switch, and holds it conductive; upon its disappearance or polarity inversion the switch is turned off and blocked. Only in the event of overcurrent is the control voltage, necessary for switch-on, reduced so that a partial discharge of the input capacitance of the switch takes place, before the switch is turned off. A switch (53) is operated in the event of overcurrent to apply a voltage from a divider (RG1, RG2, R3, D2) in order to discharge the gate capacitance. USE - Protection of DMOS or IGBT switches.