The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jun. 15, 2021

Filed:

Dec. 05, 2019
Applicant:

Sandisk Technologies Llc, Addison, TX (US);

Inventors:

Abhijith Prakash, Milpitas, CA (US);

Vishwanath Basavaegowda Shanthakumar, Milpitas, CA (US);

Jiahui Yuan, Fremont, CA (US);

Assignee:

SanDisk Technologies LLC, Addison, TX (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11C 16/04 (2006.01); G11C 16/34 (2006.01); G11C 16/26 (2006.01); G11C 11/56 (2006.01); H01L 27/11582 (2017.01); H01L 27/11556 (2017.01);
U.S. Cl.
CPC ...
G11C 16/3431 (2013.01); G11C 16/0483 (2013.01); G11C 16/26 (2013.01); G11C 16/349 (2013.01); G11C 11/5642 (2013.01); G11C 11/5671 (2013.01); G11C 2211/5644 (2013.01); H01L 27/11556 (2013.01); H01L 27/11582 (2013.01);
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.


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