公开(公告)号：US20220254416A1

公开(公告)日：2022-08-11

申请号：US17173852

申请日：2021-02-11

Applicant: SanDisk Technologies LLC

Inventor： Ravi Kumar ,  Deepanshu Dutta ,  Vishwanath Basavaegowda Shanthakumar

IPC: G11C16/26 ,  G11C16/34 ,  G06F11/10

Abstract: A memory apparatus and method of operation are provided. The apparatus includes memory cells each connected to a word line and arranged in one of a plurality of blocks and configured to retain a threshold voltage corresponding to a data state. The memory cells are operable in one of a first read condition in which a word line voltage is discharged and a second read condition in which the word line voltage is coupled up to a residual voltage level. A control circuit determines a power on event and periodically apply a predetermined refresh read voltage to the word line for a predetermined period of time for each of the plurality of blocks at a specified interval based on at least one data retention factor to maintain the memory cells of the plurality of blocks in the second read condition in response to determining the power on event.

公开(公告)号：US20240127891A1

公开(公告)日：2024-04-18

申请号：US18356760

申请日：2023-07-21

Applicant: SanDisk Technologies LLC

Inventor： Abu Naser Zainuddin ,  Parth Amin ,  Xiaochen Zhu ,  Jiahui Yuan ,  Anubhav Khandelwal ,  Vishwanath Basavaegowda Shanthakumar

IPC: G11C16/10 ,  G11C16/04 ,  G11C16/16 ,  G11C16/34

CPC classification number: G11C16/10 ,  G11C16/0483 ,  G11C16/16 ,  G11C16/3459 ,  H01L25/0657

Abstract: Technology is disclosed herein in which a duration of a program pulse used to program non-volatile memory cells such as NAND may be increased responsive to a programming failure using a shorter duration program pulse. The duration of at least one program pulse may be increased for at least one group of memory cells in response to a failure to program a group using a default program pulse duration. The group that experiences the increased duration program pulse may be the same group for which the program operation failed using the shorter program pulse or may be a different group than the group for which the program operation failed using the shorter program pulse.

公开(公告)号：US11037641B1

公开(公告)日：2021-06-15

申请号：US16704817

申请日：2019-12-05

Applicant: SanDisk Technologies LLC

Inventor： Abhijith Prakash ,  Vishwanath Basavaegowda Shanthakumar ,  Jiahui Yuan

IPC: G11C16/04 ,  G11C16/34 ,  G11C16/26 ,  G11C11/56 ,  H01L27/11582 ,  H01L27/11556

Abstract: Apparatuses and techniques are described for periodically refreshing word line voltages in a memory device. A decision to perform a refresh operation is made based on the temperature and number of program-erase (P-E) cycles. In one approach, the refresh operation is not performed if the number of P-E cycles is below a threshold number and/or the temperature is below a threshold temperature. When the temperature and number of P-E cycles indicate that a refresh operation should be performed, a timer counts an elapsed time until the elapsed time reaches an allowed discharge time. The allowed discharge time can be based on the temperature, number of P-E cycles, and other factors which affect an expected number of fail bits. The allowed discharge time can also change as the temperature changes during the counting of the elapsed time.

公开(公告)号：US20210174886A1

公开(公告)日：2021-06-10

申请号：US16704817

申请日：2019-12-05

Applicant: SanDisk Technologies LLC

Inventor： Abhijith Prakash ,  Vishwanath Basavaegowda Shanthakumar ,  Jiahui Yuan

IPC: G11C16/34 ,  G11C16/04 ,  G11C16/26

Abstract: Apparatuses and techniques are described for periodically refreshing word line voltages in a memory device. A decision to perform a refresh operation is made based on the temperature and number of program-erase (P-E) cycles. In one approach, the refresh operation is not performed if the number of P-E cycles is below a threshold number and/or the temperature is below a threshold temperature. When the temperature and number of P-E cycles indicate that a refresh operation should be performed, a timer counts an elapsed time until the elapsed time reaches an allowed discharge time. The allowed discharge time can be based on the temperature, number of P-E cycles, and other factors which affect an expected number of fail bits. The allowed discharge time can also change as the temperature changes during the counting of the elapsed time.