READ REFRESH TO IMPROVE POWER ON DATA RETENTION FOR NON-VOLATILE MEMORY

    公开(公告)号:US20220254416A1

    公开(公告)日:2022-08-11

    申请号:US17173852

    申请日:2021-02-11

    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.

    Temperature and cycling dependent refresh operation for memory cells

    公开(公告)号:US11037641B1

    公开(公告)日:2021-06-15

    申请号:US16704817

    申请日:2019-12-05

    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.

    TEMPERATURE AND CYCLING DEPENDENT REFRESH OPERATION FOR MEMORY CELLS

    公开(公告)号:US20210174886A1

    公开(公告)日:2021-06-10

    申请号:US16704817

    申请日:2019-12-05

    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.

Patent Agency Ranking