A digital compass with two or more multi-axis magnetometers and a processing element to determine a heading and detect any offset error in the heading is described. One electronic device includes first and second magnetometers. The second magnetometer can be disposed at least a specified distance or co-located and offset at least a specified angle from the first magnetometer. A processing device determines a magnetic field at the electronic device using a first output from the first magnetometer, detects an offset error in the magnetic field using a second output from the second magnetometer, and reports the offset error in the magnetic field.

A measurement apparatus includes: a memory; and a processor coupled to the memory and configured to: acquire, for each of two samples which are objects made of a same material, have different sizes, and have similar shapes, magnetization curve data measured for the sample and a shape parameter including a dimension of the sample; calculate magnetization of an inner part of each of the samples based on the acquired magnetization curve data and shape parameter of the sample by using a model representing magnetization of the object by separating the magnetization of the object into a magnetization component of a surface part and a magnetization component of an inner part of the object in accordance with a volume ratio between the surface part and the inner part of the object; and output the calculated result.

A control device includes a moving portion, a magnetic element coupled to the moving portion, at least one magnetic sensing circuit responsive to magnetic fields, and at least one magnetic flux pipe structure. The magnetic element may comprise alternating positive and negative sections configured to generate a magnetic field. The magnetic element may be any shape, such as circular, linear, etc. The magnetic sensing circuit may be radially offset from the magnetic element, and the magnetic flux pipe structure may be configured to conduct the magnetic field generated by the magnetic element towards the magnetic sensing circuit. The magnetic element may generate the magnetic field in a first plane, and the magnetic sensing may be responsive to magnetic fields in a second direction that is angularly offset from the first plane. The magnetic flux pipe structure may redirect the magnetic field towards the magnetic sensing circuit in the second direction.

A control device includes a moving portion, a magnetic element coupled to the moving portion, at least one magnetic sensing circuit responsive to magnetic fields, and at least one magnetic flux pipe structure. The magnetic element may comprise alternating positive and negative sections configured to generate a magnetic field. The magnetic element may be any shape, such as circular, linear, etc. The magnetic sensing circuit may be radially offset from the magnetic element, and the magnetic flux pipe structure may be configured to conduct the magnetic field generated by the magnetic element towards the magnetic sensing circuit. The magnetic element may generate the magnetic field in a first plane, and the magnetic sensing may be responsive to magnetic fields in a second direction that is angularly offset from the first plane. The magnetic flux pipe structure may redirect the magnetic field towards the magnetic sensing circuit in the second direction.

A sensor device comprising: a lead frame; a first/second semiconductor die having a first/second sensor structure at a first/second sensor location, and a plurality of first/second bond pads electrically connected to the lead frame; the semiconductor dies having a square or rectangular shape with a geometric center; the sensor locations are offset from the geometrical centers; the second die is stacked on top of the first die, and is rotated by a non-zero angle and optionally also offset or shifted with respect to the first die, such that a perpendicular projection of the first and second sensor location coincide.

Systems and methods for marking the location and extent of an anatomical region-of-interest, such as a tumor, using magnetic seeds whose position and orientation are measured or otherwise detected using a detection device that includes two or more magnetic sensors are described. One or more magnetic seeds are implanted to mark and define the center and extent of an anatomical region-of-interest and a magnetic sensor-based detector system is used to accurately identify the location of the magnetic seeds.

Methods and apparatus for a current sensor having an elongate current conductor having an input and an output and a longitudinal axis. First, second, third and fourth magnetic field sensing elements are coupled in a bridge configuration and positioned in a plane parallel to a surface of the current conductor such that the second and fourth magnetic field sensing elements comprise inner elements and the first and third magnetic field sensing elements comprise outer elements. Embodiments of the sensor reduce the effects of stray fields on the sensor.

A magnetic field detection device, containing a) a first soft magnetic body containing a1) a first plate including a first surface having a first outer edge; and a2) a first protrusion disposed directly or indirectly on the first surface of the first plate at a first arrangement position set back from the first outer edge, the first protrusion including a first tip on an opposite side to the first surface; and b) a magnetic detector provided in a vicinity of the first tip, wherein the magnetic detector has a magnetic sensing direction along the first surface, and the first protrusion is capable of bending a direction of a first magnetic flux, which comes into the first plate, along the first surface.

A magnetic field sensor may include a plurality of MTJ elements. Each MTJ element of has a state indicated by a magnetic moment direction of a sensing layer relative to a pinned, reference layer in an absence of an external magnetic field. The plurality of MTJ elements are arranged into two identical sets of at least two MTJ elements, where each MTJ element in each respective set has a different state. The states of the MTJ elements are arranged in a manner to measure the external magnetic field regardless of the direction of the external magnetic field. The MTJ elements include identical layers, and are electrically serially connected.

A magnetic sensor capable of reducing noise caused by an interference magnetic field and capable of outputting a highly accurate signal in accordance with changes in a detected magnetic field includes a magnetic detection element, a first magnetic body having a first surface and a second surface, which is opposite to the first surface, and a second magnetic body positioned approximately in the center of the first magnetic body in the short direction on the first surface of the first magnetic body. The magnetic detection element is provided to be opposite to the second magnetic body with the first magnetic body interposed in between and positioned approximately in the center of the first magnetic body in the short direction. The magnetic sensing direction of the magnetic detection element is a direction approximately parallel to the short direction of the first magnetic body and the second magnetic body, and a width W1 of the first magnetic body is larger than a width W2 of the second magnetic body.