Patent ID: 6529358
Filing Date: 2003-03-04
Classification: H02H

Abstract:
A protection circuit comprising:a supply terminal, an earth terminal, an input terminal which receives a voltage signal and an output terminal; a first series transistor, a current-receiving electrode of which is linked to a node which receives a voltage substantially equal to the voltage of the input terminal; a current-delivery electrode of the first series transistor coupled to the output terminal, and a second transistor for controlling the first series transistor; wherein the second transistor is an amplifier, with a current-receiving electrode loaded by a top load element linked to the supply terminal, a current-delivery electrode loaded by a bottom load element linked to the earth terminal, and a control electrode receiving a voltage that is substantially equal to the voltage of the input terminal; and a control electrode of the first series transistor linked to the second transistor on the top load element side, wherein the first series transistor conducts current between its current delivery electrode and current receiving electrode unless the voltage from its control electrode drops from excessive current from the output terminal.