Abstract: The protection device comprises a MOS transistor formed on the substrate of the integrated circuit and connected between a circuit pad and a reference terminal of the integrated circuit. A thyristor formed on the substrate is connected between the pad and the reference terminal. The control electrode of this thyristor consists of a region of the substrate in such a way that the thyristor can be triggerred by a current of charge carriers produced in the substrate by avalanche when a voltage rise occurs between the substrate and the drain of the MOS transistor.

Abstract: This invention relates to a process for servo-controlling a magnitude TI depending on a parameter .theta., whereby: the variations in time of a second magnitude TG which varies as a function of the parameter .theta. and to which the magnitude TI is related are monitored; a control signal TGE=TDS+TER is provided, TER being a function of the deviation between the reference value TR and the real value TI of the first magnitude, and the value of TDS being equal to the arithmetical mean between maximum and minimum values, TGEMX and TGEMN respectively, of the second magnitude TG determined previously; and the value of the parameter .theta. is adjusted to servo-control the second magnitude TG by the calculated value TGE.