Magnetic field sensors for detecting absolute position of multi-track targets

A system comprising:

• a target comprising a plurality of tracks, wherein a first one of the plurality of tracks is spaced from a second one of the plurality of tracks by a predetermined distance;
• and
• a magnetic field sensor for sensing an absolute position of the target, comprising:
• a first magnetic field sensing element disposed proximate to a first track of the plurality of tracks and configured to generate a first periodic magnetic field signal in response to movement of the first track;
• a second magnetic field sensing element disposed proximate to the second track of the plurality of tracks and configured to generate a second periodic magnetic field signal in response to movement of the second track, wherein the first periodic magnetic field signal and the second periodic magnetic field signal have a phase separation associated with the predetermined distance between the first track and the second track that does not change with movement of the target and wherein each of the first magnetic field signal and the second magnetic field signal has a constant reference potential;
• a third magnetic field sensing element disposed proximate to a third track of the plurality of tracks configured to generate the constant reference potential in response to movement of the third track;
• a position detection module configured to use the first magnetic field signal, the second magnetic field signal, and the constant reference potential to generate a position value indicative of the absolute position of the target;
• and
• an output format module coupled to receive the position value and configured to generate an output signal of the magnetic field sensor.