Protection device against the driving effect of parasitic transistors in monolithic integrated circuits

US4775912A · kind A · utility

Assignee

• SGS Microlelettronic S.p.A. · IT

Inventors

• Pietro Menniti · Milano, IT
• Angelo Alzati · Bollate, IT

Key dates

• Filing date: Oct 7, 1986
• Grant date: Oct 4, 1988
• Expiry date: Oct 7, 2006

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D89/60

Abstract

Described is a protection device for power PNP transistors against the anomalous driving effect of parasitic transistors which are excited, under certain limit conditions, in bipolar type monolithic integrated circuits. The device is of simple integration and requires essentially the use of a PNP protection transistor connected with its emitter and collector respectively to the emitter or to a node at a higher potential than the latter and to the base of the PNP transistor to be protected and physically made on the chip in a position essentially adjacent to the PNP transistor to be protected.