Current conveyor and method for readout of MTJ memories
AssigneeMotorola, Inc.
InventorPeter Naji
Life of this patent
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Abstract
A current conveyor for readout of a magnetic tunneling junction memory cell is coupled to a data readout line connected to at least one MTJ memory cell. The current conveyor includes a FET with a source terminal coupled to a current source and a drain terminal coupled to the data readout line. The gate terminal of the FET is connected to an output terminal of an operational amplifier connected to receive negative feedback from the data readout line and to receive a bias voltage on a second input terminal. The current conveyor has very low input impedance so that minimum data readout line swing is achieved.
Claims23
A current conveyor for readout of a magnetic tunneling junction memory cell comprising:
- a data readout line connected to at least one magnetic tunneling junction memory cell;
- a current source;
- a transistor having a control terminal, a first current terminal, and a second current terminal, the first current terminal being coupled to the current source and the second current terminal being coupled to the data readout line;
- and
- an operational amplifier having an output terminal connected to the control terminal of the transistor, the operational amplifier having a first input terminal connected to the data readout line and a second input terminal adapted to be coupled to a bias voltage.
A current conveyor for readout of a magnetic tunneling junction memory cell comprising:
- a data readout line connected to at least one magnetic tunneling junction memory cell;
- a current source;
- a first transistor having a control terminal, a first current terminal, and a second current terminal, the first current terminal of the first transistor being coupled to the current source and the second current terminal of the first transistor being coupled to the data readout line;
- and
- a first operational amplifier having an output terminal connected to the control terminal of the first transistor, the first operational amplifier having a first input terminal connected to the first current output terminal of the first transistor and a second input terminal adapted to be coupled to a bias voltage;
- a second transistor having a control terminal, a first current terminal, and a second current terminal, the first current terminal of the second transistor being coupled to the current source and the second current terminal of the second transistor being coupled to a current return, and the cell further including a second operational amplifier having an output terminal connected to the control terminal of the second transistor, the second operational amplifier having a first input terminal connected to the current source and a second input terminal adapted to be coupled to a second bias voltage;
- a circuit for providing a reference voltage output signal;
- and
- a comparator having a first input terminal connected to the control terminal of the second transistor and a second input terminal connected to receive the reference voltage output signal.
A current conveyor for readout of a magnetic tunneling junction memory cell comprising:
- an array of magnetic tunneling junction memory cells arranged in rows and columns;
- a plurality of data readout lines associated with the array, each data readout line being connected to at least one magnetic tunneling junction memory cell of the array of cells;
- each data readout line having a current conveyor coupled thereto and each current conveyor including
- a current source,
- a transistor having a control terminal, a first current terminal, and a second current terminal, the first current terminal being coupled to the current source and the second current terminal being coupled to the data readout line, and
- an operational amplifier having an output terminal connected to the control terminal of the transistor, the operational amplifier having a first input terminal connected to the data readout line and a second input terminal adapted to be coupled to a bias voltage.
Dependencies are inferred from the claim text.