Reference cell scheme for MRAM
US7499314B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 14, 2007 |
| Grant date | Mar 3, 2009 |
| Priority date | — |
| Expiry date | Dec 14, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C11/16
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An MRAM reference cell sub-array provides a mid-point reference current to sense amplifiers. The MRAM reference cell sub-array has MRAM cells arranged in rows and columns. Bit lines are associated with each column of the sub-array. A coupling connects the bit lines of pairs of the columns together at a location proximally to the sense amplifiers. The MRAM cells of a first of the pair of columns are programmed to a first magneto-resistive state and the MRAM cells of a second of the pair of columns are programmed to a second magneto-resistive state. When one row of data MRAM cells is selected for reading, a row of paired MRAM reference cells are placed in parallel to generate the mid-point reference current for sensing. The MRAM reference sub-array may be programmed electrically or aided by a magnetic field. A method for verifying programming of the MRAM reference sub-array is discussed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.