Analog Devices International Unlimited Company

Christian-albrechts-universitat Zu Kiel

Enno Lage

Jochen Schmitt

Jan Kubik

Monsoon Dutt

Peter James Tonge

Stephen O'Brien

Stephen A Bradshaw

Michael Joseph Browne

Bryan Patricio Aguiar Gonzalez

Cian Padraic O Dalaigh

Onur Necdet Urs

Md Tarequzzaman

Peter Meehan

Eckhard Prof Dr-Ing Quandt

A giant magnetoresistance (GMR) element is provided for use in a magnetic multi-turn sensor in which the free layer, that is, the layer that changes its magnetization direction in response to an external magnetic field so as to provide a resistance change, is thick enough to provide good shape anisotropy without exhibiting an AMR effect. To achieve this, at least a portion of the free layer comprises a plurality of layers of at least two different materials, specifically, a plurality of layers of at least a first material that is ferromagnetic and a plurality of layers of at least a second material that is known not to exhibit an AMR effect and that does not interfere with the GMR effect of the layers of ferromagnetic material.

Magnetoresistive element with free-layer and method of manufacturing same

The present disclosure provides magnetic sensor system that includes a magnetic sensing device comprising a magnetic multi-turn sensor, and an initialization device for setting the magnetic multi-turn sensor in a known state ready for use. The initialization device is in the form of a substrate, such as a printed circuit board, comprising one or more wires. A strong electrical pulse is applied to the one or more wires, which thereby generate a magnetic field that is strong enough to cause the magnetoresistive elements of the magnetic multi-turn sensor to be filled with domain walls, thereby magnetizing each element into an initialized state.

Magnetic sensor system having an initialization conductor

The present disclosure provides a magnetic multi-turn sensor comprising a continuous coil of magnetoresistive elements and a method of manufacturing said sensor. The continuous coil is formed on a substrate such as a silicon wafer that has been fabricated so as to form a trench and bridge arrangement that enables the inner and outer spiral to be connected without interfering with the magnetoresistive elements of the spiral winding in between. Once the substrate has been fabricated with the trench and bridge arrangement, a film of the magnetoresistive material can be deposited to form a continuous coil on the surface of the substrate, wherein a portion of the coil is formed in the trench and a portion of the coil is formed on the bridge.

Magnetic multi-turn sensor and method of manufacture

The present disclosure provides magnetic sensor system that includes a magnetic sensor package comprising a magnetic single turn sensor and a magnetic multi-turn sensor, and a shield arrangement for shielding the magnetic sensor from stray magnetic fields. The shielding arrangement comprises a ferromagnetic tube that houses one or more magnets and connects to an end of rotating shaft, such that rotation of the shaft causes a corresponding rotation of the ferromagnetic tube and magnets. The magnetic sensor package is positioned on a surface of a PCB substrate, which is positioned in close proximity to the ferromagnetic tube and magnet arrangement. A shielding device is then arranged in close proximity to the magnetic sensor package, for example, on the opposite side of the PCB substrate or directly between the PCB substrate and the ferromagnetic tube, to provide additional shielding of any stray magnetic fields. The shielding device may be in the form of a disc or a ring of ferromagnetic material that has a higher level of magnetic conductivity.

Magnetic sensor system

The present disclosure provides a method of monitoring the magnetic field in which a magnetic sensor is operating in to ensure that the sensor is operating within its defined magnetic window. For example, the method uses the sensor output of either a multi-turn sensor, or some other magnetoresistive sensor that is being used in conjunction with the multi-turn sensor, for example, a magnetic single turn sensor or a second multi-turn sensor, to monitor the operating magnetic field.

Method of monitoring a magnetic sensor

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Kiel, Germany

Enno Lage