Static information storage and retrieval – Systems using particular element – Magnetoresistive
Reexamination Certificate
2007-11-21
2009-08-18
Elms, Richard (Department: 2824)
Static information storage and retrieval
Systems using particular element
Magnetoresistive
C365S148000, C365S173000, C977S935000
Reexamination Certificate
active
07577021
ABSTRACT:
A spin-transfer MRAM is described that has two sub-cells each having a conductive spacer between an upper CPP cell and a lower MTJ cell. The two conductive spacers in each bit cell are linked by a transistor which is controlled by a write word line. The two CPP cells in each bit cell have different resistance states and the MTJ cell and CPP cell in each sub-cell have different resistance states. The MTJ free layer rotates in response to switching in the CPP free layer because of a large demagnetization field exerted by the CPP free layer. An improved circuit design is disclosed that enables a faster and more reliable read process since the reference is a second MTJ within the same bit cell. When RMTJ1>RMTJ2, the bit cell has a “0” state, and when RMTJ1<RMTJ2, the bit cell has a “1” state.
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Chien Jeff
Guo Yimin
Ackerman Stephen B.
Byrne Harry W
Elms Richard
MagIC Technologies, Inc.
Saile Ackerman LLC
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