Functional signal line overdrive
Devices and techniques are disclosed herein to compensate for variance in one or more electrical parameters across multiple signal lines of an array of memory cells. A compensation circuit can provide a bias signal to a first one of the multiple signal lines, the bias signal having an overdrive voltage greater than a target voltage by a selected increment for a selected overdrive period.
1. A system comprising:
an array of memory cells including multiple signal lines, each signal line configured to provide access to a group of memory cells responsive to a bias condition of the respective signal line; and
a compensation circuit configured to provide a respective bias signal to each of the multiple signal lines, each respective bias signal having an overdrive voltage greater than a target voltage by a selected one of a stored distribution of increments across the multiple signal lines and a selected overdrive period to compensate for variance in an electrical parameter across the signal lines,
wherein the selected overdrive period s fixed to a constant value.
2. The system of claim 1 , wherein
the target voltage comprises a bias threshold voltage configured to be applied to a first signal line prior to performing a memory operation.
3. The system of claim 1 , wherein the compensation circuit comprises multiple trim values to provide the respective bias signal, the multiple trim values distributed across the multiple signal lines using at, least, one of:
a linear function;
a piece-wise constant function;
a piece-wise linear function; or
a piece-wise polynomial function.
4. The system of claim 1 , comprising a memory device, wherein the memory device comprises multiple arrays of non-volatile memory cells,
wherein the compensation circuit is configured to determine the bias signals for the multiple signal lines using a relationship between the selected increments and the selected overdrive period to reduce a settling time of the target voltage on the multiple signal lines.
5. The system of claim 1 , wherein the compensation circuit is configured to determine the bias signals for the multiple signal lines using a relationship between the selected increment, and the selected overdrive period and an electrical characteristic of the array of memory cells.
6. The system of claim 5 , wherein the electrical characteristic of the array of memory cells comprises at least one of a resistance or a capacitance of at least one of the multiple signal lines.
7. The system of claim 5 , wherein the electrical characteristic of the array of memory cells comprises a range of resistances across the multiple signal lines.
8. A system comprising:
an array of memory cells including multiple signal lines, each signal line configured to provide access to a group of memory cells responsive to a bias condition of the respective signal line; and
a compensation circuit configured to provide a respective bias signal to each of the multiple signal lines, each respective bias signal having an overdrive voltage greater than a target voltage by a selected increment and a selected one of a stored distribution of overdrive periods across the multiple signal lines to compensate for variance in an electrical parameter across the signal lines,
wherein the selected increment is fixed to a constant value.
9. The system of claim 8 , wherein
the target voltage comprises a bias threshold voltage configured to be applied to a first signal line prior to performing a memory operation.
10. The system of claim 8 , wherein the compensation circuit comprises multiple trim values to provide the respective bias signal, the multiple trim values distributed across the multiple signal lines using at least one of:
a linear function;
a piece-wise constant function;
a piece-wise linear function; or
a piece-wise polynomial function.
11. The system of claim 8 , comprising a memory device, wherein the memory device comprises multiple arrays of non-volatile memory cells,
wherein the compensation circuit is configured to determine the bias signals for the multiple signal lines using a relationship between the selected increments and the selected overdrive period to reduce a settling time of the target voltage on the multiple signal lines.
12. The system of claim 8 , wherein the compensation circuit is configured to determine the bias signals for the multiple signal lines using a relationship between the selected increment and the selected overdrive period and an electrical characteristic of the array of memory cells.
13. The system of claim 12 , wherein the electrical characteristic of the array of memory cells comprises at least one of a resistance or a capacitance of at least one of the multiple signal lines.
14. The system of claim 12 , wherein the electrical characteristic of the array of memory cells comprises a range of resistances across the multiple signal lines.
15. A method comprising:
providing, using a compensation circuit, a respective bias signal to each of multiple signal lines of an array of memory cells to access a group of memory cells responsive to a bias condition of the respective signal line, each respective bias signal having an overdrive voltage greater than a target voltage by a selected one of a stored distribution of increments across the multiple signal lines and a selected overdrive period to compensate for variance in an electrical parameter across the signal lines,
wherein the target voltage comprises a bias threshold voltage configured to be applied to a first signal line prior to performing a memory operation.
16. The method of claim 15 , wherein the selected overdrive period is fixed to a constant value.
17. The method of claim 15 , comprising determining, using the compensation circuit, the bias signals for the multiple signal lines using a relationship between the selected increments and the selected overdrive period and an electrical characteristic of the array of memory cells,
wherein providing the respective bias signals comprise using multiple trim values distributed across the multiple signal lines using at least one of:
a linear function;
a piece-wise constant function;
a piece-wise linear function; or
a piece-wise polynomial function.
18. A method comprising:
providing, using a compensation circuit, a respective bias signal to each of multiple signal lines of an array of memory cells to access a group of memory cells responsive to a bias condition of the respective signal line, each respective bias signal having an overdrive voltage greater than a target voltage by a selected increment and a selected one of a stored distribution of overdrive periods across the multiple signal lines to compensate for variance in an electrical parameter across the signal lines,
wherein the target voltage comprises a bias threshold voltage configured to be applied to a first signal line prior to performing a memory operation.
19. The method of claim 18 , wherein the selected increment is fixed to a constant value.
20. The method of claim 18 , comprising determining, using the compensation circuit, the bias signals for the multiple signal lines using a relationship between the selected increments and the selected overdrive period and an electrical characteristic of the array of memory cells,
wherein providing the respective bias signals comprise using multiple trim values distributed across the multiple signal lines using at least one of:
a linear function;
a piece-wise constant function;
a piece-wise linear function; or
a piece-wise polynomial function.