Asymmetrical AMR wheatstone bridge layout for position sensor

• US 7,126,327 B1
• Filed: 07/22/2005
• Issued: 10/24/2006
• Est. Priority Date: 07/22/2005
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Busch, Nicholas F.
• Primary Examiner(s): Aurora, Reena
• Application Number:
  US11/187,327
• Time in Patent Office: 459 Days
• Field of Search: 324/207.21, 324/207.25, 324/252
• US Class Current: 324/207.21
• CPC Class Codes: G01D 5/147 influenced by the movement of a third element, the position of Hall device and the source of magnetic field being fixed in respect to each other

Abstract

A magnetic sensor includes a magnet located proximate to a target comprising a plurality of teeth and a plurality of slots formed therebetween. An integrated circuit is generally located on one side of the magnet wherein the integrated circuit comprises a plurality of asymmetrically arranged magnetoresistive bridge components, wherein the integrated circuit and the magnet are configured into a sensor package, such that the plurality of asymmetrically arranged magnetoresistive bridge components enables a detection of at least one tooth among the plurality of target teeth.

Claims

1. A magnetic sensor, comprising:

a ferrous target;

a magnet located proximate to said ferrous target, wherein said ferrous target comprises a plurality of teeth and a plurality of slots formed therebetween;

an integrated circuit formed on a substrate, wherein said integrated circuit is located on a side of said magnet wherein said integrated circuit comprises a plurality of asymmetrically arranged magnetoresistive bridge components, such that at least one magnetoresistive bridge component of said plurality of asymmetrically arranged magnetoresistive bridge components comprises a different pattern from that of at least one other magnetoresistive bridge component among said plurality of asymmetrically arranged magnetoresistive bridge components, wherein said integrated circuit and said magnet are configured into a sensor package, such that said plurality of asymmetrically arranged magnetoresistive bridge components enables a detection of at least one tooth among said plurality of teeth of said ferrous target; and

wherein said plurality of asymmetrically arranged magnetoresistive bridge components comprises a first set of magnetoresistors asymmetrically offset from a second set of magnetoresistors wherein said first and second sets of magnetoresistors are configured upon said substrate upon which said integrated circuit is formed and wherein said first set of magnetoresistors comprises a greater number of magnetoresistors than said second set of magnetoresistors.

2. The system of claim 1, wherein said plurality of asymmetrically arranged magnetoresistive bridge components comprises an asymmetrical magnetoresistive bridge circuit.

3. The system of claim 2 wherein said asymmetrical magnetoresistive bridge circuit comprises an AMR circuit wherein said first set of magnetoresistors comprise a first AMR component and a second AMR component and wherein said second set of magnetoresistors comprises a third AMR component and a fourth AMR component.

4. The system of claim 3 wherein said first AMR component is connected to said second AMR component at a second voltage node and said third AMR component is connected to said fourth AMR component at a first voltage node and wherein said first and third AMR components are connected to one another and to a magnetoresistive bridge voltage and said second and fourth AMR components are connected to one another and to a ground.

5. The system of claim 1 wherein said plurality of asymmetrically arranged magnetoresistive bridge components comprise AMR runners.