Darlington transistor circuit

US4618875A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventor

• Peter Flohrs · Reutlingen, DE

Key dates

• Filing date: Aug 8, 1983
• Grant date: Oct 21, 1986
• Expiry date: Aug 8, 2003

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D84/642

Abstract

A Darlington transistor circuit having a power transistor and a driver transistor is proposed. The two transistors are monolithically integrated in a common substrate (10) by a planar process, the substrate forming the collector zones of the two transistors. On the main surface of the substrate (10) there is a passivation layer (13) covering this main surface with the exception of contact windows. The base-collector junctions of the two transistors are protected by a metal electrode (15), which is located above the passivation layer (13) and extends up to a stop ring (14), which is disposed beneath the passivation layer (13) in the substrate (10). The potential at the cover electrode (15) is adjustable with the aid of a voltage divider (16). (FIG. 3).