Magnetic storage device with voltage generator that varies voltages according to temperature
A magnetic storage device includes a memory cell including a magnetoresistive effect element. The megnetoresistive effect element includes a storage layer and a reference layer. The magnetic storage device also includes a first line electrically coupled to a first terminal of the magnetoresistive effect element, a second line electrically coupled to a second terminal of the magnetoresistive effect element, and a write driver. The write driver supplies a first voltage to the first line in a first write operation in which a first resistance value of the magnetoresistive effect element is changed to a second resistance value smaller than the first resistance value, and supplies a second voltage different from the first voltage to the second line in a second write operation in which the second resistance value of the magnetoresistive effect element is changed to the first resistance value.
1. A magnetic storage device comprising:
a memory cell including a magnetoresistive effect element, the megnetoresistive effect element including a storage layer and a reference layer;
a first line electrically coupled to a first terminal of the magnetoresistive effect element;
a second line electrically coupled to a second terminal of the magnetoresistive effect element; and
a write driver,
wherein the write driver supplies a first voltage to the first line in a first write operation in which a first resistance value of the magnetoresistive effect element is changed to a second resistance value smaller than the first resistance value, and supplies a second voltage different from the first voltage to the second line in a second write operation in which the second resistance value of the magnetoresistive effect element is changed to the first resistance value.
2. The magnetic storage device of claim 1 , wherein the first voltage is lower than the second voltage.
3. The magnetic storage device of claim 2 , wherein the second voltage is lower than a power supply voltage.
4. The magnetic storage device of claim 1 , wherein a current flowing through the magnetoresistive effect element with the second resistance value in the first write operation is smaller than a current flowing through the magnetoresistive effect element with the second resistance value in the second write operation.
5. The magnetic storage device of claim 1 , wherein a current flowing through the magnetoresistive effect element with the first resistance value in the first write operation is smaller than a current flowing through the magnetoresistive effect element with the first resistance value in the second write operation.
6. The magnetic storage device of claim 1 , wherein the write driver includes:
a first transistor having a first terminal electrically coupled to the first line and a second terminal electrically coupled to the first voltage, the first transistor being set to an on state in the first write operation to supply the first voltage to the first line and being set to an off state in the second write operation, and
a second transistor having a first terminal electrically coupled to the second line and a second terminal electrically coupled to the second voltage, the first transistor being set to the on state in the second write operation to supply the second voltage to the second line and being set to the off state in the first write operation.
7. The magnetic storage device of claim 6 , wherein the first transistor has a smaller gate size than the second transistor.
8. The magnetic storage device of claim 6 , further comprising a current sink including:
a third transistor having a first terminal electrically coupled to the first line and a second terminal electrically coupled to a third voltage lower than the first voltage and the second voltage, the third transistor being set to the off state in the first write operation and being set to the on state in the second write operation, and
a fourth transistor having a first terminal electrically coupled to the second line and a second terminal electrically coupled to the third voltage, the fourth transistor being set to the on state in the first write operation and being set to the off state in the second write operation.
9. The magnetic storage device of claim 8 , wherein:
the first transistor and the second transistor have a first polarity, and
the third transistor and the fourth transistor have a second polarity different from the first polarity.
10. The magnetic storage device of claim 9 , wherein:
the first transistor has a gate providing a first signal,
the second transistor has a gate providing a second signal inverting the first signal,
the third transistor has a gate providing a third signal inverting the second signal, and
the fourth transistor has a gate providing a fourth signal inverting the first signal.
11. The magnetic storage device of claim 10 , further comprising a signal generator configured to generate a fifth signal and a sixth signal inverting the fifth signal, the signal generator including:
a first inverter inputting the fifth signal and outputting the first signal,
a second inverter inputting the first signal and outputting the fourth signal,
a third inverter inputting the sixth signal and outputting the second signal, and
a fourth inverter inputting the second signal and outputting the third signal.
12. The magnetic storage device of claim 6 , wherein the first voltage has a negative correlation with a temperature.
13. The magnetic storage device of claim 12 , wherein the second voltage is uncorrelated with the temperature.
14. The magnetic storage device of claim 12 , wherein the second voltage has a positive correlation with the temperature.