Patent ID: 8680846
Filing Date: 2014-03-25
Classification: G01R

Abstract:
1. A magnetic field sensor, comprising: at least two magnetic field sensing elements; a first switching circuit coupled to the at least two magnetic field sensing elements, wherein the first switching circuit is configured to couple the at least two magnetic field sensing elements into a measured-field-sensing configuration and into a reference-field-sensing configuration, wherein the first switching circuit is configured to couple the at least two magnetic field sensing elements in parallel so as to respond in cooperation in the presence of an external magnetic field when coupled in the measured-field-sensing configuration, and to couple the at least two magnetic field sensing elements such that the responses to the external magnetic field oppose one another when coupled in the reference-field-sensing configuration, and wherein the first switching circuit is operable to switch back and forth alternately between the measured-field-sensing configuration and the reference-field-sensing configuration at a first switching rate to provide a magnetic field signal, wherein the first switching circuit is configured to generate the magnetic field signal comprising: a processing circuit coupled to receive the magnetic field signal; and a feedback circuit coupled to receive a signal representative of the magnetic field signal from the processing circuit and configured to generate a feedback signal to control at least one of a bias signal applied to drive the at least two magnetic field sensing elements or a gain of the processing circuit.