Variable reluctance sensor interface with integration based arming threshold

摘要

An interface for processing a variable reluctance sensor signal provided by a variable reluctance sensor including an integrator, an arming comparator and a detect circuit. The integrator includes an input for receiving the variable reluctance sensor signal and an output providing an integrated signal indicative of total flux change of the variable reluctance sensor. The arming comparator compares the integrated signal with a predetermined arming threshold and provides an armed signal indicative thereof. The detect circuit provides a reset signal after the armed signal is provided to reset the integrator. A corresponding method of processing the variable reluctance sensor signal is also described.

主权项

1. A method of processing a variable reluctance sensor signal provided by a variable reluctance sensor, comprising:
integrating the variable reluctance sensor signal and providing a corresponding integrated signal indicative of a total flux change of the variable reluctance sensor; comparing the integrated signal with a predetermined arming threshold and providing a corresponding armed signal; comparing the variable reluctance sensor signal with a reference signal and providing a zero detect signal indicative thereof; clearing the integrated signal after the armed signal is provided; providing a crossing signal when the zero detect signal is provided after the armed signal is provided; holding the crossing signal in reset until the zero detect signal is provided; releasing the crossing signal from reset when the zero detect signal is provided; and after releasing the crossing signal from reset, providing the crossing signal in response to the armed signal being provided.