Adaptive erase voltage based on temperature
Aspects of a storage device including a memory and controller are provided which allow for erase voltages applied during erase operations to be adaptively changed at elevated temperatures to reduce erase time and prevent erase failures. In response to detecting a lower temperature of the memory, the controller applies a first erase voltage to cells in a block of a die, and in response to detecting a higher temperature of the memory, the controller applies a second erase voltage larger than the first erase voltage to the cells in the block of the die. The controller may apply the different erase voltages depending on whether the temperature of the die falls within respective temperature ranges or meets a respective temperature threshold, which may change for different dies. As a result, successful erase operations at higher temperatures may be achieved.
1. A storage device, comprising:
a memory comprising a cell; and
a controller configured to apply a first erase voltage to a substrate of the cell to erase the cell within a number of erase loops in response to a first temperature of the memory, to minimally increase the first erase voltage to a second erase voltage larger than the first erase voltage in response to a second temperature of the memory, and to apply the second erase voltage to the substrate of the cell to erase the cell within a same number of erase loops, wherein the second temperature is higher than the first temperature and the second erase voltage is a minimum erase voltage above the first erase voltage for erasing the cell within the same number of erase loops.
2. The storage device of claim 1 , wherein the memory comprises a block including a plurality of cells, and wherein the controller is configured to apply the first erase voltage to the cells of the block in response to the first temperature and to apply the second erase voltage to the cells of the block in response to the second temperature.
3. The storage device of claim 1 , wherein the memory comprises a first die including a plurality of blocks, the blocks each including a plurality of cells, and wherein the controller is configured to apply the first erase voltage to the cells of each of the blocks in response to the first temperature and to apply the second erase voltage to the cells of each of the blocks in response to the second temperature.
4. The storage device of claim 3 , wherein the controller is configured to store in the memory a mapping for the first die between the first erase voltage and the first temperature and between the second erase voltage and the second temperature.
5. The storage device of claim 3 , further comprising a second die including a plurality of cells, wherein the controller is configured to apply the first erase voltage to the cells of the second die in response to a first temperature of the second die, and wherein the controller is configured to apply the second erase voltage to the cells of the second die in response to a second temperature of the second die.
6. The storage device of claim 5 , wherein the second temperature of the second die is different than the second temperature of the first die.
7. The storage device of claim 5 , wherein the controller is configured to store in the memory a second mapping between the first erase voltage and the first temperature of the second die and between the second erase voltage and the second temperature of the second die.
8. A storage device, comprising:
a memory comprising a first die including a plurality of cells; and
a controller configured to apply a first erase voltage to each of the cells to erase the cells within a number of erase loops in response to the first die being within a first temperature range, to minimally increase the first erase voltage to a second erase voltage larger than the first erase voltage in response to the first die being within a second temperature range, and to apply the second erase voltage to each of the cells to erase the cells within a same number of erase loops, wherein the second temperature range includes higher temperatures than the first temperature range and the second erase voltage is a minimum erase voltage above the first erase voltage for erasing the cell within the same number of erase loops.
9. The storage device of claim 8 , wherein the controller is configured to store in the memory a mapping for the first die between the first erase voltage and the first temperature range and between the second erase voltage and the second temperature range.
10. The storage device of claim 8 , further comprising a second die including a plurality of cells, wherein the controller is configured to apply the first erase voltage to the cells of the second die in response to the second die being within a first temperature range of the second die, and wherein the controller is configured to apply the second erase voltage to the cells of the second die in response to the second die being within a second temperature range of the second die.
11. The storage device of claim 10 , wherein the second temperature range of the second die is different than the second temperature range of the first die.
12. The storage device of claim 10 , wherein the controller is configured to store in the memory a second mapping between the first erase voltage and the first temperature range of the second die and between the second erase voltage and the second temperature range of the second die.
13. A storage device, comprising:
a memory comprising a first die and a second die, the first die including a first cell and the second die including a second cell;
a controller configured to apply a first erase voltage to the first cell to erase the first cell within a first number of erase loops when a temperature of the first die does not meet a first temperature threshold, to minimally increase the first erase voltage to a second erase voltage when the temperature of the first die meets the first temperature threshold, and to apply the second erase voltage to the first cell to erase the first cell within the first number of erase loops, wherein the second erase voltage is a minimum erase voltage above the first erase voltage for erasing the first cell within the first number of erase loops, and
wherein the controller is further configured to apply a third erase voltage to the second cell to erase the second cell within a second number of erase loops when a temperature of the second die does not meet a second temperature threshold, to minimally increase the third erase voltage to a fourth erase voltage when the temperature of the second die meets the second temperature threshold, and to apply the fourth erase voltage to the second cell to erase the second cell within the second number of erase loops, wherein the fourth erase voltage is another minimum erase voltage above the third erase voltage for erasing the second cell within the second number of erase loops, and the second temperature threshold is different than the first temperature threshold.
14. The storage device of claim 13 , wherein the controller is configured to store in the memory the first temperature threshold and the second temperature threshold.