| CPC G01B 7/30 (2013.01) [G01R 33/0047 (2013.01); G01R 33/072 (2013.01); G01R 33/091 (2013.01)] | 20 Claims |
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1. A method, comprising:
employing in a sensor IC package a first set of magnetic field sensing elements located at a first position and, a second set of magnetic field sensing elements located at a second position, and a third set of magnetic field sensing elements located at a third position, wherein the first, second, and third sets of magnetic field sensing elements each have a first magnetic field sensing element, not shared with any other of the first, second or third sets, with a first axis of sensitivity and a second magnetic field sensing element, not shared with any other of the first, second or third sets, with a second axis of sensitivity, wherein the first and second axes of sensitivity are orthogonal, and wherein the first, second, and third sets of magnetic field sensing elements are aligned and spaced apart from each other on a common line, wherein the sensor IC package is positioned in relation to a target comprising a two-pole magnet, and wherein the first and second axes of sensitivity and the common line are perpendicular to an axis about which the target rotates;
processing a first differential signal comprising signals for the first axis of sensitivity from the first and second sets of magnetic field sensing elements and a second differential signal comprising signals for the second axis of sensitivity from the first and second sets of magnetic field sensing elements to determine an absolute position of the target, said processing including performing offset and gain correction on the first and second differential signals;
generating a first secondary angle position from the first and third sets of magnetic field sensing elements;
comparing a difference between the absolute position of the target and the first secondary angle position to a first threshold; and
identifying a fault in the sensor IC package based on said comparison.
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