Nxp B.v.

Stephan Marauska

Jörg Kock

Dennis Helmboldt

Edwin Jan Schapendonk

Jaap Ruigrok

Jan Przytarski

Mark Isler

Ralf Van Otten

Marijn Nicolaas Van Dongen

Bernd Offermann

Hartmut Matz

Harmut Matz

Thomas Hain

Berkan Zorlubas

A system includes an encoder magnet, a magnetic field sensor, and a shield structure. The encoder magnet is configured to rotate about an axis of rotation and is configured to produce a measurement magnetic field. The magnetic field sensor is axially displaced away from the encoder magnet and is configured to detect the measurement magnetic field. The shield structure at least partially surrounds both of the encoder magnet and the magnetic field sensor for shielding against stray magnetic fields. The shield structure attaches to a secondary structure. The shield structure and the encoder magnet may be coupled via the secondary structure so that they are commonly rotational. Alternatively, the sensor package and the shield structure are coupled via the secondary structure so that they are nonrotational relative to the encoder magnet.

System with magnetic field shield structure

A magnetic field sensor includes at least two magnetoresistive (MR) sensor elements arranged in a half-bridge configuration. Each of the MR sensor elements includes a magnetic region having a magnetic anisotropy with a resultant magnetization. The magnetic anisotropy is created using an oblique incident deposition (OID) technique, with the magnetic regions being deposited at a nonzero deposition angle relative to a reference line oriented perpendicular to a surface of the magnetic field sensor. A system includes an encoder and the half-bridge configuration of the sensor elements. The encoder produces an external magnetic field, having predetermined magnetic variations in response to motion of the encoder, the magnetic field being detectable by the sensor elements. The resultant magnetization of the sensor elements is aligned by OID in a preferred direction perpendicular to the direction of the external magnetic field instead of utilizing a permanent magnet structure for providing a bias magnetic field.

Magnetic field sensor, system, and oblique incident deposition fabrication method

A system includes a magnet having an axis of rotation, the magnet being configured to produce a magnetic field. The system further includes a plurality of magnetoresistive sensor elements, each of the magnetoresistive sensor elements having a magnetic free layer configured to generate a vortex magnetization pattern in the magnetic free layer, and the magnetoresistive sensor elements being configured to produce output signals in response to the magnetic field. A rotation angle of a rotating element to which the magnet is coupled may be determined using the plurality of output signals.

Magnetic field sensor system and method for rotation angle measurement

A system includes a magnet configured to produce a magnetic field, the magnet having an asymmetric magnetization configuration that produces a distinct feature in the magnetic field. The asymmetric magnetization configuration can be produced via an asymmetric physical characteristic, nonuniform magnetization strengths, nonuniform magnetization distributions, off-centered magnet, and so forth. Magnetic field sensors are configured to produce output signals in response to the magnetic field, the output signals being indicative of the distinct feature in the magnetic field. A processing circuit receives the output signals and determines a rotation angle for the magnet using the output signals, the rotation angle having a range of 0-360&#xb0;.

System and method for angle sensing using magnet having asymmetric magnetization configuration

A system for determining angular position includes a magnet having at least four poles and an axis of rotation, wherein the magnet produces a magnetic field. A first magnetic field sensor produces a first output signal and a second magnetic field sensor produces a second output signal in response to the magnetic field. The magnetic field sensors are operated in a saturation mode in which the magnetic field sensors are largely insensitive to the field strength of the magnetic field. Thus, the first output signal is indicative of a first direction of the magnetic field and the second output signal is indicative of a second direction of the magnetic field. Methodology performed by a processing circuit entails combining the first and second output signals to obtain a rotation angle value of the magnet in which angular error from a stray magnetic field is at least partially canceled.

Angular sensor system and method of stray field cancellation

A magnetic field sensor includes a magnetic sense element and a shield structure formed on a substrate. The shield structure fully encircles the magnetic sense element for suppressing stray magnetic fields along a first axis and a second axis, both of which are parallel to a surface of the substrate and perpendicular to one another. A magnetic field is oriented along a third axis perpendicular to the surface of the substrate, and the magnetic sense element is configured to sense a magnetic field along the first axis. A magnetic field deflection element, formed on the substrate proximate the magnetic sense element, redirects the magnetic field from the third axis into the first axis to be sensed as a measurement magnetic field by the magnetic sense element. At least two magnetic field sensors, each fully encircled by a shield structure, form a gradient unit for determining a magnetic field gradient.

Stray magnetic field robust magnetic field sensor and system

A system includes a magnetic sense element for detecting an external magnetic field along a sensing axis and a magnetic field source proximate the magnetic sense element for providing an auxiliary magnetic field along the sensing axis. The magnetic sense element produces a first output signal having a magnetic field signal component, responsive to the external magnetic field, that is modulated by an auxiliary magnetic field signal component responsive to the auxiliary magnetic field. A processing circuit identifies from the first output signal an influence of a magnetic interference field on the auxiliary magnetic field signal component, the magnetic interference field being directed along a non-sensing axis of the magnetic sense element, and applies a correction factor to the magnetic field signal component to produce a second output signal in which the influence of the magnetic interference field is substantially removed.

Magnetoresistive sensor with stray field cancellation and systems incorporating same

A system includes first and second magnetic sense elements for producing first and second output signals, respectively, in response to an external magnetic field along a sensing axis parallel to a plane of the first sense element, a magnetization direction of the second element being rotated in the plane relative to a magnetization direction of the first element. The second output signal differs from the first output signal in dependency to a magnetic interference field along a non-sensing axis of the first magnetic field. A processing circuit, receives the first and second output signals, identifies from a relationship between the first and second output signals an influence of the magnetic interference field on the first output signal, and applies a correction factor to the first output signal to produce a resultant output signal in which the influence of the magnetic interference field is substantially removed.

Magnetoresistive sensor systems with stray field cancellation utilizing auxiliary sensor signals

A system comprises at least one magnetic field sensor having a magnetic sense element formed on a substrate. The sense element senses a magnetic field along a sense axis oriented in a first direction parallel to a surface of the substrate. A shield structure is formed on the substrate. The shield structure has first and second shield portions and the magnetic sense element is disposed between the shield portions. Each of the shield portions includes a body and first and second brim segments extending from opposing ends of the body. The body is aligned parallel to a second direction perpendicular to the first direction and parallel to the surface of the substrate. The brim segments are aligned substantially parallel to the first direction. The shield portions are arranged in mirror symmetry with the brim segments of each of the shield portions extending toward one another.

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Kaltenkirchen, Germany

Stephan Marauska