Magnetic field orientation sensor and angular position sensor using same
AssigneeMelexis Technologies SA
InventorChristian Schott
Life of this patent
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Abstract
A magnetic field sensor structure having a number of inner, outer and intermediate electrodes, arranged in a particular manner, such that groups of four electrodes can be used to form horizontal Hall elements, whereby neighboring Hall elements “share” one of the two readout electrodes. Multiple Hall elements may be biased and readout simultaneously. A modulated or unmodulated readout-technique may be used. Integrated magnetic concentrator may be added to the structure. The number of Hall elements may be odd or even. The structure can be used e.g. to measure the magnetic field of a 2-pole, 4-pole or 6-pole ring or disk magnet.
Claims16
A magnetic field sensor comprising:
- a structure comprising a ring shaped well provided upon a bulk substrate, and comprising a number of inner electrodes arranged at equidistant angular positions on an inner circle concentric with the well, and the same number of outer electrodes arranged at equidistant angular positions on an outer circle concentric with the well and radially aligned with the inner electrodes for forming pairs of biasing electrodes, and the same number of readout electrodes arranged at equidistant angular positions on an intermediate circle concentric with the well, but angularly shifted with respect to the inner and outer electrodes over 180° divided by said number;
- and a biasing-and-readout circuit comprising a plurality of switches for selectively applying a progressive succession of differently directed bias currents to a pair of biasing electrodes, and for selectively reading a differential Hall voltage over a progressive succession of two readout electrodes located at an equal distance to the selected outer biasing electrode, said biasing electrodes and said readout electrodes forming a horizontal Hall element, said differential Hall voltage being indicative of the relative magnitude of a magnetic field components at the location of said Hall element.
Dependencies are inferred from the claim text.