MOSFET GATE PROTECTING CIRCUIT

摘要

PURPOSE:To prevent the breakdown of an MOSFET due to the surge component of a gate driving voltage, by providing a voltage limiting circuit constituted by constant voltage diodes between a gate and a source. CONSTITUTION:Constant voltage diodes 2 and 3 are inserted between the gate and the source of an MOSFET 1 in the reverse direction to each other. When the diodes 2 and 3 are set so that the value of a limiting voltage becomes less than the withstanding voltage between the gate and the source of the FET 1, the breakdown due to an excessive surge component can be prevented.