Allegro Microsystems, LLC

Commissariat a L'energie Atomique Et Aux Energies Alternatives

Rémy Lassalle-Balier

Jeffrey Eagen

Paolo Campiglio

Damien Dehu

Bryan Cadugan

Paul A David

Alexander Latham

Maxime Rioult

Andrea Foletto

Jean-Michel Daga

Noémie Belin

Claude Fermon

Yannick Vuillermet

Pierre Belliot

Christophe Hoareau

Sam Tran

Solène Bastien

Amal Hamdache

Julien Voillot

Shaun Veilleux

Kamil Akmaldinov

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.

Angle sensor with a single die using a single target

A system, comprising: a printed circuit board; a first conductor having a first central longitudinal axis, the first conductor having a first through-hole that is formed therein; a second conductor having a second central longitudinal axis; and a first current sensor that is mounted on the printed circuit board, the first current sensor being disposed at least partially inside the first through-hole, the first current sensor including a first pair of magnetic field sensing elements, the magnetic field sensing elements in the first pair being aligned with a first alignment axis that is arranged at a first angle relative to the second central longitudinal axis, the first angle being less than 75 degrees.

Current sensor system

A system, comprising a target, a first receiving coil array, and a second receiving coil array. The target includes: (i) a first array of conductive features that are arranged in a line or arc and separated from one another by voids, and (ii) a second array of conductive features that are arranged in a line or arc and separated from one another by voids, the conductive features in the first array being staggered with respect to the conductive features in the second array. The first receiving coil array is configured to sense a first magnetic field that is associated with the first array of conductive features. The second receiving coil array is configured to sense a second magnetic field that is associated with the second array of conductive features.

Position sensing method

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.

Magnet structure for back-biased sensors

In one aspect, a magnetic field current sensor includes an annihilation detector. The annihilation detector includes an annihilation bridge that includes magnetoresistance elements. The annihilation detector also includes a current bridge that includes at least two of the magnetoresistance elements, a first comparator configured to compare an output signal from the annihilation bridge and a second comparator configured to compare an output signal from the current bridge. An output of the annihilation detector indicates whether an annihilation exists in one or more of the magnetoresistance elements using at least one of the outputs signals of the first and second comparators.

Magnetic field current sensor to reduce stray magnetic fields

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.

Linear sensor with dual spin valve element having reference layers with magnetization directions different from an external magnetic field direction

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.

Dual double-pinned spin valve element having magnet bias with increased linear range

In one aspect, an angle sensor includes magnetic-field sensing elements that include a first pair, a second pair, a third pair and a fourth pair of magnetic-field sensing elements; and processing circuitry configured to determine an angle of a rotating ring magnetic having a plurality of North-South pole pairs each having a unique period length. The processing circuitry includes a first bridge formed from the first and second pairs of magnetic-field sensing elements and a second bridge formed from the third and fourth pairs of magnetic-field sensing elements. The angle includes a value from 0&#xb0; to 360&#xb0;. The first, second, third and fourth pairs of magnetic-field sensing elements are each disposed on a first axis. The first, second, third and fourth pairs of magnetic-field sensing elements each have a sensitivity in a first direction along the first axis. The angle sensor is formed on a single die.

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.

Magnetic field sensor

In one aspect, an angle sensor includes a first linear sensor and a second linear sensor. A first magnetic-field direction of a target magnet measured by the first linear sensor is substantially equal to a second magnetic-field direction of the target magnet measured by the second linear sensor. The first linear sensor, the second linear sensor and the target magnet are on an axis. The angle sensor determines an angle of a magnetic field.

Reducing stray magnetic field effect on an angle sensor

In one aspect, a magnetic field sensor includes a plurality of tunneling magnetoresistance (TMR) elements that includes a first TMR element, a second TMR element, a third TMR element and a fourth TMR element. The first and second TMR elements are connected to a voltage source and the third and fourth TMR elements are connected to ground. Each TMR element has a pillar count of more than one pillar and the pillar count is selected to reduce the angle error below 1.0&#xb0;.

Reducing voltage non-linearity in a bridge having tunneling magnetoresistance (TMR) elements

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.

Linear bridges having nonlinear elements

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 having non-zero values and the range of horizontal magnetic field intensity values are associated with vertical magnetic field intensity values having zero Oersted (Oe) values. A reference angle indicates an angle the magnetoresistance element is most sensitive to changes in a magnetic field.

Linear bridge having nonlinear elements for operation in high magnetic field intensities

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&#x2212;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.

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Bures sur Yvette, France

Rémy Lassalle-Balier