Magnetic field sensor and method for operating the magnetic field sensor
AssigneeMelexis Technologies SA
InventorsRadivoje Popovic, Christian Schott
Life of this patent
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Abstract
A magnetic field sensor for the measurement of at least one component of a magnetic field comprises a ferromagnetic core that serves as a magnetic field concentrator, an excitation coil and a read-out sensor. The read-out sensor preferably comprises two sensors arranged in the vicinity of the outer edge of the ferromagnetic core and measures the at least one component of the magnetic field. The ferromagnetic core is ring-shaped or disc-shaped. On operation of the magnetic field sensor, a current is temporarily applied to the excitation coil in order to bring the ferromagnetic core into a state of predetermined magnetization in which the magnetization of the ferromagnetic core produces no signal in the read-out sensor.
Claims20
A magnetic field sensor for the measurement of at least one component of a magnetic field, comprising
- a ring-shaped ferromagnetic core attached to a semi-conductor chip that spans a plane with the at least one component of the magnetic field to be measured and that serves as magnetic field concentrator, whereby the ferromagnetic core is magnetized with a predetermined magnetization,
- a read-out sensor, whereby the read-out sensor comprises at least one sensor that is integrated into the semiconductor chip and arranged in the vicinity of an outer edge of the ferromagnetic core and that measures the at least one component of the magnetic field,
- an excitation coil and a first electronic circuit for the temporary application of a current to the excitation coil in order to restore the predetermined magnetization in the ferromagnetic core, wherein said predetermined magnetization produces no signal in the read-out sensor, and
- a second electronic circuit for the operation of the first electronic circuit, the read-out sensor and for processing a signal delivered by the read-out sensor.
A method for operating a magnetic field sensor for the measurement of at least one component of a magnetic field, in which the magnetic field sensor comprises a ring-shaped ferromagnetic core having a predetermined magnetization attached to a semiconductor chip the ferromagnetic core spanning a plane with the at least one component of the magnetic field to be measured and serving as magnetic field concentrator, and a read-out sensor having at least one sensor integrated into the semiconductor chip and arranged in the vicinity of an outer edge of the ferromagnetic core whereby the read-out sensor measures the at least one component of the magnetic field, the method comprising the step of magnetizing the ferromagnetic core at specific times by temporary application of a current to an excitation coil for restoring the predetermined magnetization of the ferromagnetic core, wherein the predetermined magnetization in the ferromagnetic core produces no signal in the read-out sensor.
Dependencies are inferred from the claim text.