Hybrid analog and digital memory device
View Patent ↗A memory cell including a floating gate transistor including a floating gate, and an analog sensor element adjacent to the floating gate, where an electrical characteristic of the analog sensor element is affected by an amount of charge on the floating gate.
1. A memory cell comprising:
a floating gate transistor comprising a floating gate; and
an analog sensor element adjacent to the floating gate, wherein an electrical characteristic of the analog sensor element is affected by an amount of charge on the floating gate.
2. The memory cell of claim 1 , wherein the analog sensor element comprises a magnetoresistive sensor, and wherein the resistance of the magnetoresistive sensor is affected by the amount of charge on the floating gate.
3. The memory cell of claim 2 , wherein the magnetoresistive sensor comprises a magnetic tunnel junction.
4. The memory cell of claim 1 , wherein the analog sensor element comprises an inductive sensor, and wherein the inductance of the inductive sensor is affected by the amount of charge on the floating gate.
5. The memory cell of claim 1 , wherein the analog sensor element comprises a capacitive sensor, and wherein the capacitance of the capacitive sensor is affected by the amount of charge on the floating gate.
6. The memory cell of claim 1 , wherein the analog sensor element comprises a piezoelectric sensor, and wherein the resonant frequency of the piezoelectric sensor is affected by the amount of charge on the floating gate.
7. A memory device comprising:
a plurality of memory cells, wherein at least one memory cell of the plurality of memory cells comprises:
a floating gate transistor comprising a floating gate; and
an analog sensor element adjacent to the floating gate, wherein an electrical characteristic of the analog sensor element is affected by the amount of charge on the floating gate;
write circuitry electrically connected to the at least one floating gate transistor, wherein the write circuitry comprises a digital-to-analog converter; and
read circuitry electrically connected to the at least one analog sensor element, wherein the read circuitry comprises an analog-to-digital converter.
8. The memory device of claim 7 , wherein the analog sensor element comprises at least one of:
a resistive sensor, wherein the resistance of the resistive sensor is affected by the amount of charge stored by the floating gate;
an inductive sensor, wherein the inductance of the inductive sensor is affected by the amount of charge stored by the floating gate;
a capacitive sensor, wherein the capacitance of the capacitive sensor is affected by the amount of charge stored by the floating gate; or
a piezoelectric sensor, wherein the resonant frequency of the piezoelectric sensor is affected by the amount of charge on the floating gate.
9. The memory device of claim 7 , wherein the analog-to-digital converter is configured to convert a signal indicative of the electrical characteristic of the analog sensor element to a bit.
10. The memory device of claim 7 , wherein the analog sensor is configured such that each respective amount of charge from a plurality of different amounts of charge stored by the floating gate corresponds to a respective electrical characteristic value of a plurality of electrical characteristic values, and wherein the analog-to-digital converter is configured to convert a signal indicative of the each respective electrical characteristic value to a corresponding plurality of bits.
11. The memory device of claim 10 , wherein each corresponding plurality of bits is unique.
12. The memory device of claim 10 , wherein the digital-to-analog converter is configured to convert a bit to be written to the at least one memory cell to a corresponding analog electrical signal applied between a source and a drain of the floating gate transistor.
13. The memory device of claim 10 , wherein the digital-to-analog converter is configured to convert a plurality of bits to be written to the at least one memory cell to a corresponding analog electrical signal applied between a source and a drain of the floating gate transistor.
14. The memory device of claim 13 , wherein the corresponding analog electrical signal is unique to the plurality of bits.
15. A method comprising:
converting a plurality of bits to be written to a memory cell to a corresponding analog electrical signal, wherein the memory cell comprises a floating gate transistor comprising a floating gate and an analog sensor element adjacent to the floating gate, wherein an electrical characteristic of the analog sensor element is affected by the amount of charge on the floating gate; and
applying the analog electrical signal to a control gate of the floating gate transistor to cause an amount of charge to be on the floating gate, wherein the amount of charge is related to the analog electrical signal.
16. The method of claim 15 , wherein the plurality of bits comprises a first plurality of bits and the corresponding analog electrical signal is a first analog electrical signal, and the memory cell is a first memory cell, the method further comprising:
converting a second, different plurality of bits to be written to a second memory cell to a second corresponding analog electrical signal, wherein the second memory cell comprises a floating gate transistor comprising a floating gate and an analog sensor element adjacent to the floating gate, wherein an electrical characteristic of the analog sensor element is affected by the amount of charge on the floating gate, and wherein the second analog electrical signal is unique to the second, different plurality of bits and the first analog electrical signal is unique to the first plurality of bits; and
applying the second analog electrical signal to a control gate of the floating gate transistor of the second memory cell to cause an amount of charge to be on the floating gate, wherein the amount of charge is related to the second analog electrical signal.
17. The method of claim 15 , further comprising:
measuring a signal indicative of the electrical characteristic of the analog sensor element; and
converting the signal indicative of the electrical characteristic to a bit.
18. A method comprising:
measuring a signal indicative of an electrical characteristic of an analog sensor element included in a memory cell, wherein the memory cell comprises a floating gate transistor comprising a floating gate and an analog sensor element adjacent to the floating gate, wherein an electrical characteristic of the analog sensor element is affected by the amount of charge on the floating gate; and
converting the signal indicative of the electrical characteristic to a bit.
19. The method device of claim 18 , wherein:
the analog sensor is configured such that each respective amount of charge from a plurality of different amounts of charge on the floating gate corresponds to a respective electrical characteristic value of a plurality of electrical characteristic values, and
converting the signal indicative of the electrical characteristic to the bit comprises converting a respective signal indicative of the a respective electrical characteristic value to a corresponding plurality of bits.
20. The method of claim 19 , wherein each corresponding plurality of bits is unique.