US 12,270,869 B2
Magnet structure for back-biased sensors
Rémy Lassalle-Balier, Bures sur Yvette (FR); Jeffrey Eagen, Manchester, NH (US); and Damien Dehu, La-Ville-du-Bois (FR)
Assigned to Allegro MicroSystems, LLC, Manchester, NH (US)
Filed by Allegro MicroSystems, LLC, Manchester, NH (US)
Filed on Jan. 21, 2022, as Appl. No. 17/648,601.
Prior Publication US 2023/0236268 A1, Jul. 27, 2023
Int. Cl. G01R 33/07 (2006.01); G01R 33/09 (2006.01)
CPC G01R 33/07 (2013.01) [G01R 33/093 (2013.01); G01R 33/098 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A magnetic field sensor comprising:
three or more magnetic field sensing elements spaced apart from each other in a direction along a first axis, each of the three or more magnetic field sensing elements comprising at least two segments; and
a magnet structure to provide a bias magnetic field about the three or more magnetic field sensing elements, the magnet structure including a plurality of layers attached together that alternate between magnetic layers and non-magnetic layers in the direction along the first axis, at least two of the magnetic layers having a first width and at least one of the magnetic layers having a second width different than the first width,
wherein a first segment of the at least two segments of each of the three or more magnetic field sensing elements is positioned above a central axis of the magnet structure and a second segment of the at least two segments of each of the three or more magnetic field sensing elements is positioned below the central axis of the magnet structure.