Phototransistor light sensor having a feedback arrangement

US6657179B1 · kind B1 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Christiane Henno · Lörrach, DE
• Roger Bauer · Reutlingen, DE
• Stephan Mettler · Reutlingen, DE

Key dates

• Filing date: Apr 12, 2002
• Grant date: Dec 2, 2003
• Expiry date: Apr 12, 2022

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F39/8057

Abstract

A light sensor having increased sensitivity and improved reaction speed includes a phototransistor and a source-follower transistor as an impedance converter for a potential of a main electrode of the phototransistor, and a second transistor as a feedback element between the second main electrode of the phototransistor and its control electrode.