Patent ID: 7852662
Filing Date: 2010-12-14
Classification: G11C

Abstract:
1. A spin-torque MRAM cell array comprising: a plurality of spin-torque MRAM cells arranged in rows and columns, each spin-torque MRAM cell comprising: a plurality of bit lines, each bit line associated with one column of the columns of the plurality of spin-torque MRAM cells and connected to a second terminal of said magnetic tunnel junction element; a plurality of word lines, each word line associated with one row of the plurality of spin-torque MRAM cells and connected to a gate terminal of said select switching device of each spin-torque MRAM cell on each row to control activation and deactivation of said select switching device; a plurality of source select lines, each source select line placed orthogonally to said plurality of bit lines and associated with one pair of rows of said plurality of spin-torque MRAM cells and connected to a source terminal of said select switching device of each of said spin-torque MRAM cells on the associated pair of rows of said plurality of spin-torque MRAM cells wherein each source select line transmits a source line input signal applied to the source of the select switching device of at least one of the plurality of spin-torque MRAM cells on a selected word line and is set at a first logic level during a first writing step of selected spin-torque MRAM cells on the selected word line and subsequently toggled to a second logic level during a second writing step, wherein the first logic level is different from the second logic level; and a plurality of column write select devices, each column write select device associated with one column of said plurality of spin-torque MRAM cells and having a source terminal connected to the associated bit line of said plurality of bit lines, a drain terminal connected to receive a data input signal and a gate terminal connected to receive one of a plurality of column write select signals.