Darlington circuit comprising a field effect transistor and a bipolar output transistor

摘要

A Darlington circuit comprises a field effect transistor and a bipolar transistor monolithically integrated on a semiconductor body of a first conductivity type. In order to reduce the residual voltage which drops off between the emitter and the collector of the output transistor in the current-conducting condition, the emitter of the output transistor is composed of a plurality of emitter regions of the first conductivity type which are located in a plurality of island-shaped semiconductor regions of the second conductivity type, which thus serves as base regions for the output transistor. The lateral spacing between an emitter region and a source region of the field effect transistor provided in one and the same island-shaped semiconductor region is selected smaller than the thickness of the semiconductor body between its principle surfaces which are provided with contacts for the emitter terminal and the collector terminal.