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Magic MRAM Cells

IP.com Disclosure Number: IPCOM000019664D
Publication Date: 2003-Sep-24

Publishing Venue

The IP.com Prior Art Database

Related People

Daniel Braun Yu Lu


MRAM cells store information in the direction of the magnetization of a soft magnetic layer. In MRAM cell arrays, the cells interact and therefore the required writing field of a given field is shifted by an amount depending on the information stored in neighboring cells. This problem is solved to a large degree in the present invention by 1.) adjusting cell size and cell pitch in such a way that from the most important first layer of cells around a given one (containing 8 cells) to good approximation only 5 different field values arise. Cells/arrays adjusted in this way will be called magic cells. 2.) by measuring the information content of the 4 nearest neighbors before writing a cell and adapting the write current correspondingly to one of the 5 different values The invention therefore allows to reliably write a given cell even in dense arrays, where the interaction problem is expected to become worse with increasing integration density; and it allows to do so with only 5 predefined write current add-ons instead of 9, as one would have from the nearest neighbors for non-magic MRAM cells.