Programming scheme for segmented word line MRAM array
AssigneesMagIC Technologies, Inc., Applied Spintronics, Inc.
InventorsXizeng Shi, Po-Kang Wang, Hsu Kai Yang
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Abstract
An MRAM array has a plurality of MRAM devices that are arranged in rows and columns with segmented word lines. A magnetic biasing field is coupled to each of the MRAM devices. The MRAM devices are programmed by providing a bidirectional bit line current to a selected bit line of the plurality of bit lines and a word line current pulse to one word line segment of one row of word line segments by discharging coupled word line segments. The field biasing device may be permanent magnetic layers or write biasing lines in proximity to the fixed magnetic layer of each of the MRAM and has a magnetic orientation equivalent to the magnetic orientation of a word line segment magnetic field generated by the word line current pulse.
Claims25
An MRAM array comprising:
- a plurality of MRAM devices arranged in rows and columns;
- a plurality of bit lines, each bit line associated with one column of the columns of the plurality of MRAM devices and adjoined to a free magnetic layer of each MRAM device of said column;
- a plurality of word lines, each word line associated with one row of the plurality of MRAM devices and comprising multiple word line segments, said word line segments in close proximity to a fixed magnetic layer of each MRAM device of a sub-grouping of said one row of MRAM devices;
- an MRAM programming circuit in communication with each of the plurality of bit lines and each of the multiple word line segments of the plurality of word line, said programming circuit providing a bidirectional bit line current to a selected bit line of the plurality of bit lines and a word line current pulse to one word line segment of one row of word line segments;
- and
- a field biasing device having a magnetic coupling to each of the plurality of MRAM devices to provide a magnetic biasing field to each of the MRAM device.
A method for programming an MRAM array comprising the steps of:
- providing said MRAM array, said MRAM array comprising
- a plurality of MRAM devices arranged in rows and columns;
- a plurality of bit lines, each bit line associated with one column of the columns of the plurality of MRAM devices and adjoined to a free magnetic layer of each MRAM device of said column;
- a plurality of word lines, each word line associated with one row of the plurality of MRAM devices and comprising multiple word line segments, said word line segments in close proximity to a fixed magnetic layer of each MRAM device of a sub-grouping of said one row of MRAM devices;
- providing a bidirectional bit line current to a selected bit line of the plurality of bit lines;
- and
- providing a word line current pulse to one word line segment of one row of word line segments;
- and
- providing a magnetic biasing field to each of the plurality of MRAM devices.
An apparatus for programming an MRAM array comprising the steps of:
- means for providing said MRAM array, said MRAM array comprising
- a plurality of MRAM devices arranged in rows and columns;
- a plurality of bit lines, each bit line associated with one column of the columns of the plurality of MRAM devices and adjoined to a free magnetic layer of each MRAM device of said column;
- a plurality of word lines, each word line associated with one row of the plurality of MRAM devices and comprising multiple word line segments, said word line segments in close proximity to a fixed magnetic layer of each MRAM device of a sub-grouping of said one row of MRAM devices;
- means for providing a bidirectional bit line current to a selected bit line of the plurality of bit lines;
- means for providing a word line current pulse to one word line segment of one row of word line segments;
- and
- means for providing a magnetic biasing field to each of the plurality of MRAM devices.
Dependencies are inferred from the claim text.