Electronic fuse

Abstract

An electronic fuse comprising an integrated circuit having a control output terminal coupled to a control electrode of a power semiconductor switching device, the power semiconductor switching device being coupled in series with a load between first and second potentials, the integrated circuit further comprising a current sense input for sensing the current through the power semiconductor switching device, the integrated circuit further comprising a driver circuit for driving the power semi-conductor switching device, the driver circuit being coupled to a current limiting circuit responsive to the sensed current in the power semiconductor switching device, the current limiting circuit controlling the driver circuit whereby if the current through the power semiconductor switching device exceeds a predetermined threshold, the current limiting circuit generates a command to pulse the power semiconductor switching device on and off in a period of pulsed operation to maintain the current in the power semiconductor switching device below a predetermined level, further comprising a first timer circuit for limiting the period of pulsed operation to a preprogrammed first duration and further for controlling the power semiconductor switching device whereby if two commands to pulse the power semiconductor switching device are generated by the current limiting circuit within a duration less than a predetermined second duration, the power semiconductor switching device is turned off.

Dependencies are inferred from the claim text.