Component null in order conservation the integration MOS power transistor from voltage gradient

摘要

A voltage gradient protective device for a monolithic vertical power MOS (VDMOS) transistor and logic circuit component, in which the transistor drain is formed by the first conductivity type substrate (1, 2) and the logic components are formed in a second conductivity type surface well (10), comprises a resistor (40) in series with each of the first conductivity type regions (31) connected to the logic circuit earth or to a node of low impedance wrt. earth. Preferably, the other terminal of the resistor (40) is connected to an earth contact (32) on the well (10) and the resistor corresponds to a polysilicon region formed on a thick oxide layer (41).