Amr Sensor Element for Angle Measurement

• US 20080043381A1
• Filed: 12/20/2004
• Published: 02/21/2008
• Est. Priority Date: 01/07/2004
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Butzmann, Stefan
• Granted Patent: US 7,602,176 B2
• Time in Patent Office: Days
• US Class Current: 360/327
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06
• CPC Class Codes: G01R 33/09 Magnetoresistive devices
• CPC Class Codes: G01R 33/096 anisotropic magnetoresistance sensors

Abstract

In order to provide a magnetoresistive angle sensor (100) comprising a sensor device for detecting an angle (α) of an external magnetic field relative to a reference axis of the sensor device, which allows measurement of the angle (α) without the measurement result being affected by manufacturing errors, it is proposed that the sensor device comprises a flat AMR layer (14, 15) with one electrical contact (K_o) for applying a current (I) and a plurality of electrical contacts (K_i) for measuring a flow of current through the AMR layer (14,15).

Claims

1. A magneto-resistive angle sensor comprising a sensor device for detecting an angle (α

) of an external magnetic field relative to a reference axis of the sensor device, characterized in that the sensor device comprises a flat AMR layer with one electrical contact for applying a current (I) and a plurality of electrical contacts for measuring a flow of current through the AMR layer.

2. A magneto-resistive angle sensor as claimed in claim 1, characterized in that the sensor device is a circular AMR layer.

3. A magneto-resistive angle sensor as claimed in claim 2, characterized in that the electrical contact for applying a current is arranged in the center of the circular AMR layer.

4. A magneto-resistive angle sensor as claimed in claim 2, characterized in that a plurality of electrical contacts are arranged equidistantly at the edge of the circular AMR layer, in particular eight electrical contacts.

5. A magneto-resistive angle as claimed in claim 1, characterized in that the sensor device is a semicircular AMR layer.

6. A magneto-resistive angle sensor as claimed in claim 5, characterized in that the electrical contact for applying a current is arranged in the center of an associated full circle.

7. A magneto-resistive angle sensor s claimed in claim 5, characterized in that a plurality of electrical contacts (K_i) are arranged equidistantly at the semicircular edge of the semicircular AMR layer (15), in particular five electrical contacts.

8. A magneto-resistive angle sensor as claimed in claim 1, characterized in that the plurality of electrical contacts are placed at the same potential, in particular at ground potential.

9. A magneto-resistive angle sensor as claimed in claim 1, characterized in that the AMR layer is a Permalloy layer applied to a silicon support substrate.

10. The use of a magneto-resistive angle sensor as claimed in claim 1 in motor vehicle technology, wherein the magneto-resistive angle sensor monitors the position of at least one of the following:

pedal, throttle.