Angle sensor
AssigneeAllegro MicroSystems, LLC
InventorsTill-Jonas Ostermann, Simon E. Rock, Emil Pavlov
Life of this patent
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Abstract
Methods and apparatus for a magnetic field sensor having first and second arrays of magnetic field sensing elements with at least first and second orthogonal axes of sensitivity. The first array of magnetic field sensing elements is spaced a first distance from the second array of magnetic field sensing elements. A turns counter counts a number of times a magnetic pole pair of a moving target passes the magnetic field sensing elements with a selected pole pair resolution and a module determines absolute angular position of the target from differential signals from the first and second arrays of magnetic field sensing elements and the turns counter. The first distance is configured to match a pitch of the poles of the target.
Claims26
A magnetic field sensor, comprising:
- a first array of magnetic field sensing elements;
- a second array of magnetic field sensing elements, wherein the first array of magnetic field sensing elements is spaced a first distance from the second array of magnetic field sensing elements, wherein the first and second arrays of magnetic field sensing elements each have at least first and second axes of sensitivity, wherein the first axis of sensitivity is orthogonal to the second axis of sensitivity;
- a turns counter to count a number of times a magnetic pole pair of a moving target passes the magnetic field sensing elements with a selected pole pair resolution;
- and
- a module to determine absolute angular position of the target from differential signals from the first and second arrays of magnetic field sensing elements and the turns counter,
- wherein the first distance is configured to match a pitch of the poles of the target.
A method, comprising:
- employing first and second arrays of magnetic field sensing elements in a sensor, wherein the first array of magnetic field sensing elements is spaced a first distance from the second array of magnetic field sensing elements, wherein the first and second arrays of magnetic field sensing elements each have at least first and second axes of sensitivity, wherein the first axis of sensitivity is orthogonal to the second axis of sensitivity;
- counting, using a turns counter, a number of times a magnetic pole pair of a moving target passes the magnetic field sensing elements with a selected pole pair resolution;
- and
- determining absolute angular position of the target from differential signals from the first and second arrays of magnetic field sensing elements and the turns counter, wherein the first distance is configured to match a pitch of the poles of the target.
Dependencies are inferred from the claim text.