Circuits and methods using a first cycle of a signal to generate a threshold signal used for comparing to a second later cycle of the signal

摘要

A circuit to detect a movement of an object provides a threshold selection module that uses one or more threshold signals identified during a first cycle of a proximity signal prior to a second different cycle of the magnetic field signal in order to establish a threshold signal used to compare with the second cycle of the magnetic field signal. A method associated with the circuit is also described.

主权项

1. A method of detecting movement of an object, comprising:
generating a magnetic field signal with at least one magnetic field sensing element, wherein the magnetic field signal is proportional to a magnetic field associated with the object, wherein the magnetic field signal has cycles including a first cycle occurring during a first time period and a second cycle occurring during a second time period, the first time period occurring in time before the second time period; generating a tracking signal that tracks at least a portion of the magnetic field signal; using the tracking signal to generate a threshold sample in accordance with the first cycle of the magnetic field signal; and comparing the threshold sample generated in accordance with the first cycle of the magnetic field signal to the second cycle of the magnetic field signal.