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US 12,618,661 B2Granted
Reducing stray magnetic field effect on an angle sensor
AssigneeAllegro MicroSystems, LLC
InventorsRémy Lassalle-Balier, Jean-Michel Daga
Life of this patent
Estimating the term…
Abstract
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.
Claims19
An angle sensor comprising:
- a first linear sensor;
- and
- a second linear sensor,
- a first die having a first surface and an opposing second surface, the first linear sensor being disposed on the first surface of the first die;
- a second die having a first surface and an opposing second surface, the second linear sensor being disposed on the second surface of the second die;
- wherein 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,
- wherein the first linear sensor, the second linear sensor and the target magnet are on an axis,
- wherein the angle sensor determines an angle of a magnetic field by:
- detecting an amplitude and direction of a magnetic field at the first linear sensor and the second linear sensor;
- and
- calculating a difference between the magnetic field detected at the first linear sensor and the second linear sensor;
- and
- wherein the first linear sensor and the second linear sensor have a linear range equal to a maximum field range from the target magnet plus twice a maximum amplitude of a stray magnetic field, such that the first and second linear sensor each remain within a linear region, allowing the first linear sensor and the second linear sensor to avoid a saturation region.
10 more elements
An angle sensor comprising:
- a first linear sensor;
- a second linear sensor;
- a first die having a first surface and an opposing second surface, the first linear sensor being disposed on the first surface of the first die;
- a second die having a first surface and an opposing second surface, the second linear sensor being disposed on the second surface of the second die;
- a spacer layer in direct contact with the second surface of the first die and the first surface of the second die;
- and
- a printed circuit board (PCB) electrically connected to the first die by a wire,
- wherein 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,
- wherein the first linear sensor, the second linear sensor and the target magnet are on an axis, and
- wherein the angle sensor determines an angle of a magnetic field by:
- detecting an amplitude and direction of a magnetic field at the first linear sensor and the second linear sensor;
- and
- calculating a difference between the magnetic field detected at the first linear sensor and the second linear sensor, and
- wherein the first linear sensor and the second linear sensor have a linear range equal to a maximum field range from the target magnet plus twice a maximum amplitude of a stray magnetic field, such that the first and second linear sensor each remain within a linear region, allowing the first linear sensor and the second linear sensor to avoid a saturation region.
11 more elements
An angle sensor comprising:
- a first linear sensor;
- and
- a second linear sensor,
- a first die having a first surface and an opposing second surface, the first linear sensor being disposed on the first surface of the first die;
- a second die having a first surface and an opposing second surface, the second linear sensor being disposed on the second surface of the second die;
- wherein 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,
- wherein the first linear sensor, the second linear sensor and the target magnet are on an axis,
- wherein the angle sensor determines an angle of a magnetic field by:
- detecting an amplitude and direction of a magnetic field at the first linear sensor and the second linear sensor;
- and
- calculating a difference between the magnetic field detected at the first linear sensor and the second linear sensor;
- and
- wherein the first linear sensor and the second linear sensor have a linear range equal to a maximum field range from the target magnet plus twice a maximum amplitude of a stray magnetic field, such that the first and second linear sensor each remain within a linear region, allowing the first linear sensor and the second linear sensor to avoid a saturation region.
10 more elements
Dependencies are inferred from the claim text.