Differential MRAM structure with relatively reversed magnetic tunnel junction elements enabling writing using same polarity current
US8964458B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 2012 |
| Grant date | Feb 24, 2015 |
| Priority date | — |
| Expiry date | Jun 28, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C29/74
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A magnetoresistive memory has first and second magnetic tunnel junction (MTJ) elements operated differentially, each with a pinned magnetic layer and a free magnetic layer that can have field alignments that are parallel or anti-parallel, producing differential high and low resistance states representing a bit cell value. Writing a high resistance state to an element requires an opposite write current polarity through the pinned and free layers, and differential operation requires that the two MTJ elements be written to different resistance states. One aspect is to arrange or connect the layers in normal and reverse order relative to a current bias source, thereby achieving opposite write current polarities relative to the layers using the same current polarity relative to the current bias source. The differentially operated MTJ elements can supplement or replace single MTJ elements in a nonvolatile memory bit cell array.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.