Patent ID: 8907669
Filing Date: 2014-12-09
Classification: G01R

Abstract:
1. An electronic circuit for measuring a sensed current, comprising: a primary current conductor for carrying the sensed current; a magnetic field sensing element disposed proximate to the primary conductor, wherein the sensed current passing through the primary conductor results in a first magnetic field at the magnetic field sensing element; a plurality of secondary conductors disposed proximate to the magnetic field sensing element, each at a different position relative to the magnetic field sensing element; a plurality of drive circuits, each one of the plurality of drive circuits coupled to a respective one of the plurality of secondary conductors; and a selection circuit coupled to the plurality of drive circuits and operable to select ones of the plurality of drive circuits causing the selected drive circuits to drive respective currents through respective selected ones of the plurality of secondary conductors, wherein the currents passing through the selected ones of the plurality of secondary conductors result in a second magnetic field at the magnetic field sensor, wherein a magnitude of the second magnetic field is related to the selection made by the selection circuit, wherein the magnetic field sensor is responsive to a summed magnetic field corresponding to a sum of the first and second magnetic fields, and wherein the selection made by the selection circuit results in a selected sensitivity of the magnetic field sensor to the sensed current.