US 11,885,866 B2
Auto-calibration for coreless current sensors
Yannick Vuillermet, La Motte-Servolex (FR); Loïc André Messier, Vanzy (FR); Simon E. Rock, Heidelberg (DE); Maxwell McNally, Manchester, NH (US); Alexander Latham, Harvard, MA (US); and Andreas P. Friedrich, Metz-Tessy (FR)
Assigned to Allegro MicroSystems, LLC, Manchester, NH (US)
Filed by Allegro MicroSystems, LLC, Manchester, NH (US)
Filed on May 31, 2022, as Appl. No. 17/804,647.
Prior Publication US 2024/0004016 A1, Jan. 4, 2024
Int. Cl. G01R 35/00 (2006.01); G01R 15/20 (2006.01); G01R 33/07 (2006.01)
CPC G01R 35/005 (2013.01) [G01R 15/202 (2013.01); G01R 15/207 (2013.01); G01R 33/072 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An auto-calibrating current sensor configured for calibration at a mounted position relative to a given conductor, the sensor comprising:
a. a plurality of magnetic field sensing elements disposed at different locations within an integrated circuit (IC), respectively, and configured to produce a plurality of linearly independent magnetic field measurements of a magnetic field produced by a current carried by the conductor;
b. memory comprising computer-executable instructions, wherein the computer-executable instructions include an electromagnetic model of the integrated circuit and the conductor, and wherein the model is operative to determine a magnetic field at points in space due to a given current in the conductor; and
c. a processor coupled to the memory and operative to execute the computer-executable instructions, wherein, in response to executing the computer-executable instructions, the processor is configured to:
receive the plurality of linearly independent magnetic field measurements from the plurality of magnetic field sensing elements;
from the electromagnetic model, determine a plurality of coupling factors between the plurality of magnetic field sensing elements at their respective locations and the conductor, wherein each coupling factor is indicative of a magnitude of magnetic field measured per unit of current in the conductor;
based on the plurality of coupling factors and plurality of linearly independent magnetic field measurements, calculate the current applied to the conductor; and
based on the plurality of coupling factors and plurality of linearly independent magnetic field measurements, calculate the position of the integrated circuit at the mounted position relative to the conductor;
wherein the current sensor is calibrated at the mounted position to determine current flowing in the conductor.