Gm Global Technolgoy Operations, Inc.

Stephen J Valeri

Kailash Chandra Jain

Bernard A MacIver

James C Erskine

An ignition system for a spark ignited internal combustion engine wherein a source of high direct voltage is connected to a spark plug by a solid-state high voltage switch. The switch comprises a plurality of series connected metal oxide semiconductor field effect transistors which form a first string of series connected transistors. The system has a second string of series connected field effect transistors. The second string is connected in parallel with the spark plug and the second string is biased conductive when the first string is biased nonconductive. The system has a third string of series connected field effect transistors which operate as a voltage level shifter. The individual transistors that form the strings are mounted on common substrates formed of an insulating material such as sapphire.

Internal combustion engine ignition system

JMOS depletion mode transistors include back-to-back junctions in the doped polysilicon layer that serves as the gate. The polysilicon layer includes a first region of the same conductivity type as the channel in contact with the channel, and a second region, of the same conductivity type as the channel and to which the gate potential is applied, spaced apart by a region of the opposite conductivity type that serves as a sink for minority carriers in the channel. Both buried oxide layer and recessed gate JMOS transistors are included.

JMOS transistor utilizing polysilicon sinks

A vertical j-MOSFET useful as a power transistor includes a two-dimensional array of square cells in which a small fraction of the cells are replaced by a double-junction sink useful for collecting the minority carriers in the channel regions that normally will accumulate at each interface of the gate electrode and channel region.

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Warren, MI, United States of America

Stephen J Valeri