Patent ID: 6392463
Filing Date: 2002-05-21
Classification: H03K

Abstract:
An electrical load driving circuit comprising:a MOS transistor provided between a driving power supply and an electrical load and having first and second electrodes and a gate electrode controlling a channel between said first and second electrodes, for turning on and off a circuit including said driving power supply and said electrical load in accordance with a control signal via said gate electrode with a predetermined polarity in a voltage difference between said first and second electrodes of said MOS transistor with respect to one of positive and negative terminals of said driving power supply; a first clamping circuit for clamping a first voltage difference between said first and second electrodes to a first predetermined voltage when a high voltage is externally applied to a connection point between said MOS transistor and said electrical load, said high voltage generating a voltage difference between said first and second electrodes and having a polarity the same as said predetermined polarity; and a second clamping circuit for clamping said gate electrode of said MOS transistor to a predetermined potential with respect to said one of positive and negative terminals of said driving power supply to turn on said MOS transistor when said high voltage is externally applied to said connection point while said MOS transistor is turned off in accordance with said control signal.