Patent ID: 8624587

Claim:
A magnetic field sensor for measuring a direction of a magnetic field in a plane, comprising: a first sensing structure and a second sensing structure, each comprising a ring-shaped, electrically conductive well, and a predefined number N of at least eight contacts of equal size placed at equal distance from each other along the ring-shaped well and contacting the ring-shaped well, and an electronic circuit comprising at least one current source, a first processing block for processing a first Hall voltage, a second processing block for processing a second Hall voltage, and an exclusive OR gate having a first and a second input, each processing block comprising a voltage difference amplifier having an output coupled to an input of a bandpass filter having an output coupled to an input of a comparator, wherein an output of the first processing block is coupled directly or indirectly to the first input of the exclusive OR gate and an output of the second processing block is coupled directly or indirectly to the second input of the exclusive OR gate, a switching block comprising a first plurality of electronic switches associated with the contacts of the first sensing structure and a second plurality of electronic switches associated with the contacts of the second sensing structure, a timing circuit providing a clock signal for opening and closing the switches of the switching blocks according to a predetermined time scheme such that a predetermined number of contacts of the plurality of contacts of the first sensing structure form a first Hall element moving in a clockwise direction along the ring-shaped well of the first sensing structure in a predefined number of steps per turn and such that a predetermined number of contacts of the plurality of contacts of the second sensing structure form a second Hall element moving in a counterclockwise direction along the ring-shaped well of the second sensing structure in the same predefined number of steps per turn, wherein the first and second Hall element are supplied with current from the at least one current source and deliver each at least one Hall voltage to the processing blocks.