Patent ID: 7019338

Claim:
A monolithic component protecting a line against overvoltages greater than a determined positive threshold or lower than a determined negative threshold, including in antiparallel a cathode-gate thyristor and an anode-gate thyristor connected between a first terminal of the line to be protected and a reference voltage, the gate of the cathode-gate thyristor being connected to a negative threshold voltage via a gate current amplification transistor, the gate of the anode-gate thyristor being connected to a positive threshold voltage, characterized in that: the monolithic component is made in a substrate of a first conductivity type divided into wells separated by isolating walls, lower surfaces of the isolating walls being coated with insulating layers, a lower surface of the substrate being uniformly coated with a lower surface metallization, the gate current amplification transistor of the cathode-gate thyristor is made in vertical form in a first well, the cathode-gate thyristor is implemented in vertical form in a second well, the lower surface metallization links up the collector of the transistor, the anode of the cathode-gate thyristor, and the cathode of the anode-gate thyristor, a first front surface metallization connects the cathode of the cathode-gate thyristor to the anode of the anode-gate thyristor, a second front surface metallization connects the gate of the cathode-gate thyristor to the emitter of the transistor, and a third front surface metallization is in contact with the gate of the anode-gate thyristor.