Methods, devices, and systems for dealing with threshold voltage change in memory devices
AssigneeMicron Technology, Inc.
InventorsZhenlei Shen, William H. Radke, Peter Feeley
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Abstract
The present disclosure includes methods, devices, and systems for dealing with threshold voltage change in memory devices. A number of embodiments include an array of memory cells and control circuitry having sense circuitry coupled to the array. The control circuitry is configured to determine changes in threshold voltages (Vts) associated with the memory cells without using a reference cell, and adjust the sense circuitry based on the determined changes and without using a reference cell.
Claims26
A memory device, comprising:
- an array of memory cells;
- and
- control circuitry coupled to the array and configured to:
- determine changes in threshold voltages associated with the memory cells without using a reference cell by:
- sensing a state of the memory cells;
- and
- performing an error correction operation on the sensed state;
- and
- adjust a voltage used to sense a state of the memory cells based on the determined changes and without using a reference cell.
A memory device, comprising:
- an array of memory cells;
- and
- control circuitry coupled to the array and configured to:
- determine changes in threshold voltages associated with the memory cells without using a reference cell by:
- sensing threshold voltages associated with the memory cells;
- and
- determining a number of voltages that correspond to a number of states associated with the memory cells using the sensed threshold voltages, wherein each determined voltage corresponds to a respective one of the number of states;
- and
- adjust a voltage used to sense a state of the memory cells based on the determined changes and without using a reference cell.
A method for operating a memory device, comprising:
- determining changes in threshold voltages associated with a number of memory cells without using a reference cell, wherein determining changes in the threshold voltages associated with the number of memory cells includes:
- sensing a state of the number of memory cells;
- and
- performing an error correction operation on the sensed state;
- adjusting a voltage used to sense a state of the number of memory cells based on the determined changes and without using a reference cell;
- and
- sensing a state of the number of memory cells using the adjusted voltage.
A method for operating a memory device, comprising:
- determining changes in threshold voltages associated with a number of memory cells without using a reference cell, wherein determining changes in the threshold voltages associated with the number of memory cells includes:
- sensing threshold voltages associated with the memory cells;
- and
- determining a number of voltages that correspond to a number of states associated with the number of memory cells using the sensed threshold voltages, wherein each determined voltage corresponds to a respective one of the number of states;
- adjusting a voltage used to sense a state of the number of memory cells based on the determined changes and without using a reference cell;
- and
- sensing a state of the number of memory cells using the adjusted voltage.
A method for operating a memory device, comprising:
- determining changes in threshold voltages associated with a number of memory cells without using a reference cell, wherein determining changes in the threshold voltages associated with the number of memory cells includes:
- sensing threshold voltages associated with the memory cells;
- determining a number of voltages that correspond to a number of states associated with the number of memory cells using the sensed threshold voltages, wherein each determined voltage corresponds to a respective one of the number of states;
- and
- outputting the sensed threshold voltages and the determined number of voltages to an error correction code decoder;
- and
- adjusting a voltage used to sense a state of the number of memory cells based on the determined changes and without using a reference cell.
Dependencies are inferred from the claim text.