Patent ID: 7355389

Claim:
A system for determining linear position, the system comprising: a magnet having a first magnetic pole and a second magnetic pole, wherein the first magnetic pole and the second magnetic pole define an axis of the magnet; and a magnetoresistive sensor comprising a magnetoresistive sensor structure that includes a Wheatstone bridge circuit including a plurality of anisotropic magnetoresistors, the magnetoresistive sensor structure defining a plane that, in the system, is oriented out-of-plane with the axis of the magnet, wherein, in operation, the magnet travels, with respect to the magnetoresistive sensor, along a substantially linear path of travel that is substantially parallel to the plane defined by the sensor structure, such that the sensor operates in a saturation mode when the magnet is located along a given portion of the path of travel and, when operating in the saturation mode, the magnetoresistive sensor produces an electrical signal that corresponds with a linear position of the magnet along the given portion of the path of travel, the electrical signal approximates a third order polynomial and includes only a single mid-point crossing as the magnet travels along the given portion of the path of travel in a single direction.