Single channel magnetoresistance-based angle sensor

An angle sensor comprising:

• analog circuitry configured to generate an analog value having a tangent value, the analog circuitry comprising a plurality of magnetoresistance elements comprising:
• a first magnetoresistance element configured to provide a cosine value indictive of a magnetic field along a first axis;
• and
• a second magnetoresistance element configured to provide a sine value indicative of the magnetic field along a second axis orthogonal to the first axis, wherein the tangent value is determined by the cosine value and the sine value;
• an analog-to-digital converter (ADC) configured to convert the analog value to a digital value;
• and
• digital circuitry configured to receive the digital value, the digital circuitry comprising an angle processor configured to use the digital value and a fixed value in an arctangent algorithm to generate an angle of a direction of the magnetic field;
• and
• a third magnetoresistance element configured to provide the sine value indicative of the magnetic field along the second axis,
• wherein the analog circuitry comprises an amplifier having a first input connected to the first magnetoresistance element and the second magnetoresistance element, a second input connected to the first magnetoresistance element and the second magnetoresistance element and a first output connected to the second magnetoresistance element and the ADC and a second output connected to the third magnetoresistance element and the ADC.

An angle sensor comprising:

• analog circuitry configured to generate an analog value having a tangent value, the analog circuitry comprising a plurality of magnetoresistance elements comprising:
• a first magnetoresistance element configured to provide a cosine value indictive of a magnetic field along a first axis;
• and
• a second magnetoresistance element configured to provide a sine value indicative of the magnetic field along a second axis orthogonal to the first axis, wherein the tangent value is determined by the cosine value and the sine value;
• an analog-to-digital converter (ADC) configured to convert the analog value to a digital value;
• and
• digital circuitry configured to receive the digital value, the digital circuitry comprising an angle processor configured to use the digital value and a fixed value in an arctangent algorithm to generate an angle of a direction of the magnetic field;
• a bridge comprising the second magnetoresistance element;
• a third magnetoresistance element configured to provide the cosine value indicative of the magnetic field along the first axis;
• and
• a fourth magnetoresistance element configured to provide the cosine value indicative of the magnetic field along the first axis;
• wherein the analog circuitry comprises:
• a buffer connected to an output of the bridge;
• a first amplifier having a first input, a second input connected to the first magnetoresistance element and an output connected to the third magnetoresistance element and the ADC;
• a first resistor connected to the buffer and the first input of the first amplifier;
• a second resistor connected to the first input of the amplifier and the output of the first amplifier;
• a second amplifier having a first input, a second input connected to the first magnetoresistance element and an output connected to the fourth magnetoresistance element and the ADC;
• a third resistor connected to the buffer and the first input of the second amplifier;
• and
• a fourth resistor connected to the first input of the second amplifier and the output of the second amplifier.