Tdk-micronas Gmbh

Rolf Hakenes

Stefan Keller

An apparatus () for determining a stray magnetic field in the vicinity of a sensor is described. The apparatus () has a multipole permanent magnet () with four or more poles and an axis of rotation (). The multipole permanent magnet () produces a magnetic field () with magnetic field vectors (). Two vertical Hall sensors (and) are so arranged in two positions on a circular path () about the axis of rotation, such that the sum of the magnet field vectors () measured at the two positions is substantially zero.

Method and apparatus for determining a stray magnetic field in the vicinity of a sensor

A method for dynamic noise reduction of magnetic field sensor signals of a magnetic field sensor circuit with a magnetic field sensor and a switching device, wherein the magnetic field sensor provides a sensor signal to a sensor output, and wherein the switching device comprises a signal comparator, a low pass filter and a multiplexer, and wherein the switching device comprises a signal input interconnected with the sensor signal output and a signal output, and wherein the signal comparator has a first input interconnected with the signal input and a second input interconnected with the low pass filter, and a control signal output interconnected with the multiplexer. In a first method step, the sensor signal is compared to the level of a signal of the low pass filter by means of the signal comparator, and the result is compared to a predetermined threshold value.

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Glottertal, Germany

Rolf Hakenes