Variable reluctance sensor interfaces with signal pre-processing and methods of their operation

Abstract

The embodiments described herein can provide a variable reluctance sensor (VRS) interface that may reduce the probability of erroneous transitions in a resulting generated detect signal. As such, the VRS interface can improve the accuracy of position and/or motion determinations, and thus can improve the performance of a wide variety of devices that use variable reluctance sensors. To facilitate this, the VRS interface includes a pre-processing circuit configured to modify a VRS signal to prevent the modified VRS signal from dropping below a threshold value and generating erroneous transitions in the detect signal pulse between leading and lagging edges of a tooth. In one embodiment the pre-processing circuit comprises a peak and hold circuit. In another embodiment the pre-processing circuit comprises a resistor-capacitor circuit. In either case the pre-processing circuit can prevent erroneous transitions in the detect signal and thus may improve the performance and accuracy of the system.