The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 24, 2007
Filed:
Nov. 14, 2005
Romney R. Katti, Shorewood, MN (US);
Owen J. Hynes, Maple Plain, MN (US);
Daniel S. Reed, Otsego, MN (US);
Hassan Kaakani, Excelsior, MN (US);
Romney R. Katti, Shorewood, MN (US);
Owen J. Hynes, Maple Plain, MN (US);
Daniel S. Reed, Otsego, MN (US);
Hassan Kaakani, Excelsior, MN (US);
Honeywell International Inc., Morristown, NJ (US);
Abstract
A new read scheme is provided for an MRAM bit having a pinned layer (fixed) and a storage layer (free) sandwiching a nonmagnetic spacer layer. By applying a magnetic field to the bit at least partially orthogonal to the easy axis of the bit, the magnetization direction of the storage layer can be partially rotated or canted without switching the logical state of the MRAM bit. The resistivity of the bit is measured (calculated based on a voltage/current relationship) in two ways: (i) with the magnetization direction of the storage layer partially rotated in a first direction and (ii) with the magnetization direction of the storage layer in its bi-stable orientation parallel to the easy axis. Those measures can then be used to compare and determine the logical state of the storage layer. For instance, if the canted resistivity is greater than the uncanted resistivity then the magnetization directions of the pinned and storage layer are parallel, and if the canted resistivity is less than the uncanted resistivity then the magnetization directions of the pinned and storage layer are opposite.