Monolithic integrated structure to protect a power transistor against overvoltage

摘要

A structure of an electronic device having a predetermined unidirectional conduction threshold is formed on a chip of an N-type semiconductor material and includes a plurality of isolated N-type regions. Each isolated N-type region is bounded laterally by an isolating region and at the bottom by buried P-type and N-type regions which form in combination a junction with a predetermined reverse conduction threshold and means of connecting the junctions of the various isolated regions serially together. The buried N-type region of the first junction in the series is connected to a common electrode, which also is one terminal of the device, over an internal path of the N-type material of the chip, and the buried P-type region of the last junction in the series contains an additional buried N-type region which is connected electrically to a second terminal of the device.