Magnetic memory device
According to one embodiment, a magnetic memory device includes a first wiring line, a plurality of second wiring lines, a plurality of first memory cells each including a first magnetoresistance effect element and a first selector connected in series, and a first switch. A respective one of the first memory cells is connected between the first wiring line and a respective one of the second wiring lines, a first voltage is applied to the second wiring line connected to a selected first memory cell, and a second voltage is applied to the second wiring line connected to a non-selected first memory cell, a first terminal of the first switch is connected to the first wiring line, and a third voltage is applied to a second terminal of the first switch.
1. A magnetic memory device comprising:
a first wiring line which extends in a first direction;
a plurality of second wiring lines, each of which extends in a second direction intersecting the first direction;
a plurality of first memory cells, each of which includes a first magnetoresistance effect element capable of setting a high resistance state or a low resistance state in which a resistance is lower than a resistance in the high resistance state, and a first selector connected in series to the first magnetoresistance effect element; and
a first switch which includes a first terminal and a second terminal,
wherein
a respective one of the plurality of first memory cells is connected between the first wiring line and a respective one of the plurality of second wiring lines,
the magnetic memory device is configured to apply in operation a first voltage to the second wiring line connected to a selected first memory cell of the plurality of first memory cells, and a second voltage is applied to the second wiring line connected to a non-selected first memory cell of the plurality of first memory cells,
the first terminal of the first switch is connected to the first wiring line, and
the magnetic memory device is configured to apply in operation a third voltage different from the first voltage and the second voltage to the second terminal of the first switch.
2. The magnetic memory device according to claim 1 , wherein
the third voltage is higher than the first voltage and is lower than the second voltage.
3. The magnetic memory device according to claim 1 , wherein
the third voltage is higher than the second voltage and is lower than the first voltage.
4. The magnetic memory device according to claim 1 , further comprising:
a third wiring line which extends in the first direction;
a plurality of second memory cells, each of which includes a second magnetoresistance effect element capable of setting a high resistance state or a low resistance state in which a resistance is lower than a resistance in the high resistance state, and a second selector connected in series to the second magnetoresistance effect element; and
a second switch which includes a third terminal and a fourth terminal,
wherein
a respective one of the plurality of the second memory cells is connected between the third wiring line and a respective one of the plurality of second wiring lines,
the third terminal of the second switch is connected to the third wiring line, and
a respective one of the plurality of first memory cells and a respective one of the plurality of second memory cells are commonly connected to a respective one of the plurality of second wiring lines.
5. The magnetic memory device according to claim 1 , wherein
the first switch includes a third magnetoresistance effect element and a third selector connected in series to the third magnetoresistance effect element.
6. The magnetic memory device according to claim 4 , wherein
the second switch includes a fourth magnetoresistance effect element and a fourth selector connected in series to the fourth magnetoresistance effect element.
7. The magnetic memory device according to claim 1 , wherein
the first switch has the same structure as the first memory cell.
8. The magnetic memory device according to claim 4 , wherein
the first switch, the second switch, the first memory cell, and the second memory cell have the same structure.
9. The magnetic memory device according to claim 1 , further comprising:
a diode which is connected to the second terminal.
10. The magnetic memory device according to claim 1 , further comprising:
a transistor which is connected to the second terminal and has diode connection.
11. The magnetic memory device according to claim 1 , further comprising:
a current supply circuit which supplies a write current to the selected first memory cell via the first wiring line, wherein
the magnetic memory device is configured to increase the third voltage as a position of the selected first memory cell becomes farther from the current supply circuit.
12. The magnetic memory device according to claim 1 , wherein
the first magnetoresistance effect element includes a first magnetic layer having a variable magnetization direction, a second magnetic layer having a fixed magnetization direction, and a nonmagnetic layer provided between the first magnetic layer and the second magnetic layer.
13. The magnetic memory device according to claim 1 , further comprising:
a write circuit which performs a first write operation and a second write operation on the selected first memory cell, wherein
the first write operation includes writing first data to the selected first memory cell by setting the first magnetoresistance effect element to the high resistance state, and
the second write operation includes writing second data to the selected first memory cell by setting the first magnetoresistance effect element to the low resistance state.
14. The magnetic memory device according to claim 13 , wherein
the write circuit sets the first switch to an on-state after the first magnetoresistance effect element is set to the high resistance state.
15. The magnetic memory device according to claim 13 , wherein
the write circuit includes:
a first element which generates a first enable state that enables data to be written to the selected first memory cell;
a second element which generates a second enable state that enables the first switch to be set to an on-state; and
a delay circuit which controls the second element so as to generate the second enable state a predetermined time after the first element generates the first enable state.
16. The magnetic memory device according to claim 13 , wherein
the write circuit includes a current supply circuit which supplies a write current to the selected first memory cell via the first wiring line, and
the first wiring line includes a first position at which a distance to the first switch is minimum, a second position at which a distance to the selected first memory cell is minimum, and a third position at which a distance to the current supply circuit is minimum, and the first position is between the second position and the third position.
17. The magnetic memory device according to claim 13 , wherein
the write circuit applies a fourth voltage to the selected first memory cell such that the first selector of the selected first memory cell is set to an on-state and supplies a write current to the first magnetoresistance effect element of the selected first memory cell, when the first data is written to the selected first memory cell.
18. The magnetic memory device according to claim 17 , wherein
the write circuit applies a fifth voltage to the first switch when the first data is written to the selected first memory cell, and
the fifth voltage is lower than the fourth voltage.
19. The magnetic memory device according to claim 18 , wherein
when the first data is written, the first switch is set to an on-state in a case where the fifth voltage is higher than a predetermined voltage.
20. The magnetic memory device according to claim 19 , wherein
the predetermined voltage is higher than the second voltage.