US 11,852,699 B2
Linear sensor with dual spin valve element having reference layers with magnetization directions different from an external magnetic field direction
Rémy Lassalle-Balier, Bures sur Yvette (FR); and Maxime Rioult, Massy (FR)
Assigned to Allegro MicroSystems, LLC, Manchester, NH (US)
Filed by Allegro MicroSystems, LLC, Manchester, NH (US)
Filed on Feb. 28, 2023, as Appl. No. 18/175,829.
Application 18/175,829 is a continuation of application No. 17/166,301, filed on Feb. 3, 2021, granted, now 11,630,168.
Prior Publication US 2023/0204694 A1, Jun. 29, 2023
Int. Cl. G01R 33/09 (2006.01); H10N 50/10 (2023.01); H10N 50/80 (2023.01); H10N 50/85 (2023.01); G11B 5/39 (2006.01)
CPC G01R 33/093 (2013.01) [G01R 33/098 (2013.01); H10N 50/10 (2023.02); H10N 50/80 (2023.02); H10N 50/85 (2023.02); G11B 5/39 (2013.01)] 20 Claims
OG exemplary drawing
 
16. A linear sensor comprising:
at least one magnetoresistance element comprising:
a first spin valve comprising:
a first set of reference layers having a magnetization direction in a first direction; and
a first set of free layers having a magnetization direction in a second direction orthogonal to the first direction; and
a second spin valve positioned on the first spin valve, the second spin valve comprising:
a second set of reference layers having a magnetization direction in the first direction; and
a second set of free layers having a magnetization direction in a third direction orthogonal to the first direction and antiparallel to the second direction,
wherein the at least one magnetoresistance element comprises layers, including the first set of reference layers, the first set of free layers, the second set of reference layers and the second set of free layers, that are stacked one on top of another on an axis,
wherein the first direction is neither parallel nor antiparallel to a direction of a magnetic field direction that is orthogonal to the axis,
wherein the at least one magnetoresistance element detects magnetic field changes caused by a target object enabling the linear sensor to provide a differential signal indicating a linear position of the target object,
wherein the first spin valve is either a giant magnetoresistance (GMR) element or a tunneling magnetoresistance (TMR) element,
wherein the first direction and the direction of the expected magnetic field form a tilt angle, and
wherein the tilt angle is between 0° and 30°.