Patent ID: 7425821
Filing Date: 2008-09-16
Classification: G01D,G01R

Abstract:
1. A Hall effect sensor comprising: a Hall element having an output at which is provided a Hall output signal that varies in response to a magnetic field, the Hall output signal comprising a magnetic signal component and an offset signal component; a Hall plate modulation circuit having an input responsive to the Hall output signal and having an output at which is provided a modulation circuit output signal, wherein the Hall plate modulation circuit is operable to modulate the magnetic signal component or the offset signal component at a modulation frequency f an amplifier having an input responsive to the Hall plate modulation circuit output signal and an output at which is provided an amplifier output signal; and a filter having an input responsive to the amplifier output signal and an output at which is provided a sensor output signal, wherein the filter comprises an anti-aliasing filter and a discrete time selective filter tuned at the modulation frequency to remove the offset signal component, wherein the anti-aliasing filter provides a bandwidth limited signal for filtering by the selective filter, wherein the anti-aliasing filter removes frequency components above a predetermined frequency selected to prevent aliasing by the discrete time selective filter.