Patent ID: 8035943

Claim:
A protection circuit apparatus for protecting a load from an over-current, the apparatus comprising: a retriggerable fuse comprising a control circuit, the retriggerable fuse having an awakened state and a sleep state, the retriggerable fuse being capable, when in the awakened state, of selectively preventing a load current from flowing from an input to an output thereof in response to the load current exceeding a first current threshold; and an activation circuit arranged to sense the load current being drawn and cause the retriggerable fuse to enter the awakened state from the sleep state in response to the sensed load current exceeding a second current threshold; wherein the retriggerable fuse has a current-sense output to provide a current-sense output signal indicative that the load current has been sensed, the activation circuit being arranged with the control circuit to use the current-sense output signal to latch the retriggerable fuse in the awakened state, wherein the current-sense output signal is proportional to the load current; wherein the retriggerable fuse reverting to the sleep state once the current-sense output signal diminishes below a sustain current level so as to release the latch necessary to maintain the retriggerable fuse in the awakened state.