Differential perpendicular on-axis angle sensor

摘要

Embodiments relate to magnetic field angle sensors, such as on-axis magnetic field angle sensors. In an embodiment, a magnetic field angle sensor comprises a magnet having an axis of rotation, and a substrate arranged in-line with the axis of rotation. A plurality, such as at least four, of magnetic field sensor elements are arranged on a surface of the substrate, spaced apart from one another in regular increments on a closed curve in an embodiment, and are sensitive to a component of a magnetic field induced by the magnet that is parallel to the surface of the substrate on which the sensor elements are arranged. Circuitry of or coupled to the sensor elements then can estimate an angular position of the magnet, such as based on the magnetic field components sensed by the sensor elements as well as positions along the closed curve where the magnetic field component vanishes in an embodiment.

主权项

1. A magnetic field angle sensor comprising:
a magnet rotatable about an axis of rotation within an angular range; a substrate arranged proximate the magnet such that a projection of the axis of rotation intersects the substrate and comprising a first surface arranged perpendicularly with respect to the axis of rotation; at least three magnetic field sensor elements on the first surface of the substrate, the at least three magnetic field sensor elements distributed evenly within the angular range along a curve contained within a perimeter of the first surface and sensitive to magnetic field components parallel to the first surface of the substrate, wherein at least one of the at least three magnetic field sensor elements is sensitive to a magnetic field component of a first direction and at least one other of the at least three magnetic field sensor elements is sensitive to a magnetic field component of a second direction, the first direction being different from the second direction; and circuitry coupled to the at least three magnetic field sensor elements, the circuitry configured to:
determine, from magnetic field components sensed by the at least three magnetic field sensor elements, at least one position along the curve where the magnetic field component is zero; andestimate, based on the at least one position, an angular position of the magnet.