Abstract: In one aspect, a dual double-pinned spin valve element includes a first spin valve that includes a first pinned layer and a second pinned layer and a second spin valve disposed on the first spin valve and comprising a third pinned layer and a fourth pinned layer. The first, second, third and fourth pinned layers each have a magnetization in a first direction.

Abstract: According to an embodiment, a magnetic field sensor includes: one or more magnetic field sensing elements; and a magnet structure to provide a bias magnetic field about the one or more magnetic field sensing elements, the magnet structure includes alternating magnetic layers and non-magnetic layers with at least three magnetic layers.

Abstract: Methods and apparatus that can include a rotatable target to generate a sinusoidal signal in a magnetic field sensor, wherein the target includes a plurality of sinusoidal teeth to reduce angular error. A magnetic field sensor can be configured to determine a position of the target. In embodiments, a rotatable target to generate a sinusoidal signal in a magnetic field sensor can include a plurality of sinusoidal teeth and a number of harmonics to reduce angular error.

Abstract: In one aspect, a bridge includes a first magnetoresistance element having a first reference angle, a second magnetoresistance element in series with the first magnetoresistance element and having a second reference angle, a third magnetoresistance element in parallel with the first magnetoresistance element and having the first reference angle and a fourth magnetoresistance element in series with the third magnetoresistance element and having the second reference angle. An output of the bridge has a linear response over a range of horizontal magnetic field intensity values not centered about a zero value and a reference angle indicates an angle the magnetoresistance element is most sensitive to changes in a magnetic field.

Abstract: Methods and apparatus that can include a rotatable target to generate a sinusoidal signal in a magnetic field sensor, wherein the target includes a plurality of sinusoidal teeth to reduce angular error. A magnetic field sensor can be configured to determine a position of the target. In embodiments, a rotatable target to generate a sinusoidal signal in a magnetic field sensor can include a plurality of sinusoidal teeth and a number of harmonics to reduce angular error.

Abstract: Methods and apparatus for a magnetic field sensor for measuring movement of a target including a substrate and a magnet. A first bridge structure has first and second pluralities of magnetic field sensing elements spaced from each other. An axis of sensitivity of the magnetic field sensing elements is rotated at a predetermined angle with respect to an axis of rotation of the target to generate an output signal corresponding to the position of the target and a change in a property of the magnetic field generated by the magnet.

Abstract: A system includes a ring magnet having magnetic segments and configured to rotate about an axis of rotation, wherein adjacent segments have different magnetic polarities, The system can further include a substrate positioned so that a top surface of the substrate is substantially parallel to the axis of rotation and a center plane passing through the ring magnet and perpendicular to the axis of rotation of the ring magnet intersects the top surface at an intersection line. The system can further include four magnetic field sensing elements supported by the substrate and electrically coupled to form a first bridge circuit, wherein two of the four magnetic field sensing elements are positioned on one side of the intersection line and the other two of the four magnetic field sensing elements are positioned on the other side of the intersection line.

Abstract: In one aspect, a dual double-pinned spin valve element includes a first spin valve that includes a first pinned layer and a second pinned layer and a second spin valve disposed on the first spin valve and comprising a third pinned layer and a fourth pinned layer. The first, second, third and fourth pinned layers each have a magnetization in a first direction.

Abstract: In one aspect, a magnetic field angle sensor includes a bridge structure that include a sine bridge configured to generate a sinusoidal signal indicative of a magnetic field along a first axis and a cosine bridge configured to generate a cosinusoidal signal indicative of the magnetic field along a second axis that is orthogonal with respect to the first axis. One of the sine bridge or the cosine bridge includes a first set of at least two magnetoresistance elements, a second set of at least one magnetoresistance element, a third set of at least one magnetoresistance element and a fourth set of at least one magnetoresistance element. An average reference direction of the first set of at least two magnetoresistance elements is equal to an average reference direction of the third set of at least one magnetoresistance element.

Abstract: In one aspect, a bridge includes a first magnetoresistance element having a first reference angle, a second magnetoresistance element in series with the first magnetoresistance element and having a second reference angle, a third magnetoresistance element in parallel with the first magnetoresistance element and having the first reference angle and a fourth magnetoresistance element in series with the third magnetoresistance element and having the second reference angle. An output of the bridge has a linear response over a range of horizontal magnetic field values not centered about a zero value and a reference angle indicates an angle the magnetoresistance element is most sensitive to changes in a magnetic field.

Abstract: A system includes a ring magnet having magnetic segments and configured to rotate about an axis of rotation, wherein adjacent segments have different magnetic polarities, The system can further include a substrate positioned so that a top surface of the substrate is substantially parallel to the axis of rotation and a center plane passing through the ring magnet and perpendicular to the axis of rotation of the ring magnet intersects the top surface at an intersection line. The system can further include four magnetic field sensing elements supported by the substrate and electrically coupled to form a first bridge circuit, wherein two of the four magnetic field sensing elements are positioned on one side of the intersection line and the other two of the four magnetic field sensing elements are positioned on the other side of the intersection line.

Abstract: A magnetic field sensor can include four magnetoresistance elements arranged in a bridge, wherein two of the magnetoresistance elements have a response to an external or stray magnetic field that is opposite to a response of the other two magnetoresistance elements.

Abstract: A magnetoresistance element (e.g. a spin valve) for detecting a changing magnetic field includes a pinning layer, pinned layer adjacent to the pinning layer, a spacer layer adjacent to the pinned layer, and a free layer adjacent to the spacer layer and arranged so that the spacer layer is between the pinned layer and the free layer. The pinned layer has a bias with a bias direction configured to reduce an effect of a static field on the detection of the changing magnetic field.

Abstract: A magnetoresistance element (e.g. a spin valve) for detecting a changing magnetic field includes a pinning layer, pinned layer adjacent to the pinning layer, a spacer layer adjacent to the pinned layer, and a free layer adjacent to the spacer layer and arranged so that the spacer layer is between the pinned layer and the free layer. The pinned layer has a bias with a bias direction configured to reduce an effect of a static field on the detection of the changing magnetic field.

Abstract: Methods and apparatus for a magnetic field sensor for measuring movement of a target including a substrate and a magnet. A first bridge structure has first and second pluralities of magnetic field sensing elements spaced from each other. An axis of sensitivity of the magnetic field sensing elements is rotated at a predetermined angle with respect to an axis of rotation of the target to generate an output signal corresponding to the position of the target and a change in a property of the magnetic field generated by the magnet.

Abstract: In one aspect, a magnetic field angle sensor includes a bridge structure that include a sine bridge configured to generate a sinusoidal signal indicative of a magnetic field along a first axis and a cosine bridge configured to generate a cosinusoidal signal indicative of the magnetic field along a second axis that is orthogonal with respect to the first axis. One of the sine bridge or the cosine bridge includes a first set of at least two magnetoresistance elements, a second set of at least one magnetoresistance element, a third set of at least one magnetoresistance element and a fourth set of at least one magnetoresistance element. An average reference direction of the first set of at least two magnetoresistance elements is equal to an average reference direction of the third set of at least one magnetoresistance element.

Abstract: A magnetoresistance element (e.g. a spin valve) for detecting a changing magnetic field includes a pinning layer, pinned layer adjacent to the pinning layer, a spacer layer adjacent to the pinned layer, and a free layer adjacent to the spacer layer and arranged so that the spacer layer is between the pinned layer and the free layer. The pinned layer has a bias with a bias direction configured to reduce an effect of a static field on the detection of the changing magnetic field.