Protection device for integrated transistor against electrostatic discharge, for use in integrated circuits with output transistors

The protection device (CP) comprises a switching transistor (M11) connected between the gate of an output transistor (TS1) and the ground, the control means (MC) connected to the gate of the switching transistor (M11) for blocking it in the absence of electrostatic discharge at the level of the drain of the output transistor, and for making it conducting in the presence of electrostatic discharge at the level of the drain of the output transistor. The control means (MC) comprise a p-MOS transistor connected as a capacitor (M20) whose first pole (BC1) is connected to the gate of the switching transistor (M11) at a node (ND), and the second pole (BC2) is electrically connected to the drain of the output transistor, n-MOS, at a node (PAD) in the case of electrostatic discharge, a transistor (M16) connected between the node (ND) and the ground, whose gate is connected to the first supply terminal (BA1) at a supply potential (Vdd). The first supply terminal (BA1) is electrically dissociated from the drain of the output transistor inn the case of electrostatic discharge because the second supply terminal (BA2) is connected to the drain of the output transistor by the intermediary of a diode (DD). The capacitance of the capacitor (M20) is greater than the sum of the drain-source capacitance of the transistor (M16) and the capacitance of the switching transistor (M11). The transistor (M16) can be replaced by a resistor. An integrated circuit comprises an output cell with at least one output transistor and a protection device as proposed. Le dispositif de protection comporte un transistor de commutation (M11), connecté entre la grille du transistor de sortie (TS1) et la masse, et des moyens de commande (MC) reliés à la grille du transistor de commutation, aptes en l'absence de décharge électrostatique au niveau du drain du transistor de sortie, à bloquer le transistor de commutation (M11), et aptes en présence d'une décharge électrostatique au niveau du drain du transistor de sortie, à rendre conducteur le transistor de commutation (M11).