Magnetic sensor with offset magnetic field

US7504824B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Guenther Crolly · Kirchheimbolanden, DE
• Thorsten Muehge · Mainz, DE
• Rolf Schaefer · Mainz, DE
• Ernst-Dieter Weissenberger · Ober-Hilbersheim, DE

Key dates

• Filing date: Oct 21, 2005
• Grant date: Mar 17, 2009
• Expiry date: Oct 21, 2025

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/09
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method, a magnetic field sensor, and an electronic device measure and determine the magnitude and/or the direction of a magnetic field. The magnetic sensor is based on at least a first magnetoresistive-layered structure having an electric resistance depending on the magnitude of the magnetic field. The magnetic sensor generates at least a first offset magnetic field. The magnitude and the direction of the offset magnetic field can be modified to compensate the magnetic field. The electric resistance of the magnetoresistive-layered structure depends on the superposition of magnetic field and offset magnetic field. A maximum electric resistance indicates that the magnetic field is compensated by the offset magnetic field. In this case the magnitude of the magnetic field corresponds to the magnitude of the offset magnetic field, and the direction of the magnetic field is given by the reversed direction of the offset magnetic field.