Abstract: Methods and apparatus for a sensor having a TMR stack with first and second vortices that are antiferromagnetically coupled together in a synthetic anti-ferromagnet (SAF) arrangement to create a TMR free layer. Due to the opposite behavior of the vortices, and to the coupling which opposes them, relatively strong fields are needed to induce magnetic modifications in the free layer. With this arrangement, the free layer of the stack has relatively wide linear response.

Abstract: In one aspect, a method includes manufacturing a tunneling magnetoresistance (TMR) element to sense out-of-plane changes in magnetic field intensity in a magnetic field. The manufacturing includes depositing a plurality of antiferromagnetic layers having magnetization directions alternating by layer between a first direction and a second direction opposite the first direction. A top layer of the plurality of antiferromagnetic layers has a magnetization direction in the first direction. The manufacturing also includes depositing a ferromagnetic layer directly on the top layer; depositing a first multilayer structure directly on the ferromagnetic layer; depositing a metal layer directly on the first multilayer structure; and depositing a second multilayer structure directly on the metal layer. The ferromagnetic layer, the first multilayer structure, and the second multilayer structure are each parallel to an x-y plane and the first direction is either in a z-direction or in a ?z direction.

Abstract: Systems, circuits, and methods provide ring shaped TMR elements having increased linearity. Such ring shaped TMR elements provide transducer output responses to changes in input magnetic field levels that are more linear compared to prior TMR techniques and devices. In some embodiments, a free layer having a ring shape can create a circular magnetization resulting in a TMR element linearity that can be adjusted depending on the width of the ring shaped element. In some embodiments, such ring shaped TMR elements can overcome small diameter fabrication limits of prior art vortex elements.

Abstract: In one aspect, an angle sensor includes a first plurality of magnetoresistance elements located at a first location on an axis and a second plurality of magnetoresistance elements located at a second location on the axis. The first plurality of magnetoresistance elements includes a first one or more magnetoresistance elements each having a reference direction in a first direction; and a second one or more magnetoresistance elements each having a reference direction in a second direction. The second plurality of magnetoresistance elements includes a third one or more magnetoresistance elements each having a reference direction in the first direction, and a fourth one or more magnetoresistance elements each having a reference direction in the second direction. The angle sensor senses movement of a magnetic target, and the magnetic target is a ring magnet or a single pole magnet.

Abstract: Methods and apparatus for devices including TMR elements with a free layer having a vortex layer to provide a magnetic vortex, a spacer layer, a reference layer, and a bias layer to offset the vortex by magnetic exchange bias. Sensor embodiments increase linearity for enhancing sensor performance.

Abstract: Methods and apparatus for a device having a TMR element that includes a free layer, a spacer layer, and a reference layer. In embodiments, the free layer comprises a vortex layer configured to provide a magnetic vortex, and a coupling layer magnetically coupled to the vortex layer to modulate the vortex in the vortex layer.

Abstract: In one aspect, a method includes manufacturing a tunneling magnetoresistance (TMR) element to sense out-of-plane changes in magnetic field intensity in a magnetic field. The manufacturing includes depositing a plurality of antiferromagnetic layers having magnetization directions alternating by layer between a first direction and a second direction opposite the first direction. A top layer of the plurality of antiferromagnetic layers has a magnetization direction in the first direction. The manufacturing also includes depositing a ferromagnetic layer directly on the top layer; depositing a first multilayer structure directly on the ferromagnetic layer; depositing a metal layer directly on the first multilayer structure; and depositing a second multilayer structure directly on the metal layer. The ferromagnetic layer, the first multilayer structure, and the second multilayer structure are each parallel to an x-y plane and the first direction is either in a z-direction or in a ?z direction.

Abstract: In one aspect, a linear sensor includes at least one magnetoresistance element that includes a first spin valve and a second spin valve positioned on the first spin valve. The first spin valve includes a first set of reference layers having a magnetization direction in a first direction and a first set of free layers having a magnetization direction in a second direction orthogonal to the first direction. The second spin valve includes a second set of reference layers having a magnetization direction in the first direction and a second set of free layers having a magnetization direction in a third direction orthogonal to the first direction and antiparallel to the second direction. The first direction is neither parallel nor antiparallel to a direction of an expected magnetic field.

Abstract: In one aspect, an angle sensor includes a first plurality of magnetoresistance elements located at a first location on an axis and a second plurality of magnetoresistance elements located at a second location on the axis. The first plurality of magnetoresistance elements includes a first one or more magnetoresistance elements each having a reference direction in a first direction; and a second one or more magnetoresistance elements each having a reference direction in a second direction. The second plurality of magnetoresistance elements includes a third one or more magnetoresistance elements each having a reference direction in the first direction, and a fourth one or more magnetoresistance elements each having a reference direction in the second direction. The angle sensor senses movement of a magnetic target, and the magnetic target is a ring magnet or a single pole magnet.

Abstract: In one aspect, a linear sensor includes at least one magnetoresistance element that includes a first spin valve and a second spin valve positioned on the first spin valve. The first spin valve includes a first set of reference layers having a magnetization direction in a first direction and a first set of free layers having a magnetization direction in a second direction orthogonal to the first direction. The second spin valve includes a second set of reference layers having a magnetization direction in the first direction and a second set of free layers having a magnetization direction in a third direction orthogonal to the first direction and antiparallel to the second direction. The first direction is neither parallel nor antiparallel to a direction of an expected 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: In one aspect, a linear sensor includes at least one magnetoresistance element that includes a first spin valve and a second spin valve positioned on the first spin valve. The first spin valve includes a first set of reference layers having a magnetization direction in a first direction and a first set of free layers having a magnetization direction in a second direction orthogonal to the first direction. The second spin valve includes a second set of reference layers having a magnetization direction in the first direction and a second set of free layers having a magnetization direction in a third direction orthogonal to the first direction and antiparallel to the second direction. The first direction is neither parallel nor antiparallel to a direction of an expected magnetic field.

Abstract: In one aspect, a linear sensor includes at least one magnetoresistance element that includes a first spin valve and a second spin valve positioned on the first spin valve. The first spin valve includes a first set of reference layers having a magnetization direction in a first direction and a first set of free layers having a magnetization direction in a second direction orthogonal to the first direction. The second spin valve includes a second set of reference layers having a magnetization direction in the first direction and a second set of free layers having a magnetization direction in a third direction orthogonal to the first direction and antiparallel to the second direction. The first direction is neither parallel nor antiparallel to a direction of an expected magnetic field.

Abstract: A magnetic field sensor responsive to a movement of a target object can include a plurality of magnetoresistance elements arranged in a line and having a span according to y(1?1/x), where y is equal a full spatial period of the target object and where x is equal to a total quantity of magnetoresistance elements in the plurality of magnetoresistance elements. The plurality of magnetic field sensing elements is operable to generate a signal that is substantially not responsive to the movement of the target object but is responsive to stray external magnetic fields.

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 magnetic field sensor responsive to a movement of a target object can include a plurality of magnetoresistance elements arranged in a line and having a span according to y(1?1/x), where y is equal a full spatial period of the target object and where x is equal to a total quantity of magnetoresistance elements in the plurality of magnetoresistance elements. The plurality of magnetic field sensing elements is operable to generate a signal that is substantially not responsive to the movement of the target object but is responsive to stray external magnetic fields.

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.