- 专利标题: Dynamic tuning of first read countermeasures
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申请号: US15627738申请日: 2017-06-20
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公开(公告)号: US10157676B2公开(公告)日: 2018-12-18
- 发明人: Liang Pang , Yingda Dong , Jiahui Yuan , Charles Kwong
- 申请人: SanDisk Technologies LLC
- 申请人地址: US TX Addison
- 专利权人: SanDisk Technologies LLC
- 当前专利权人: SanDisk Technologies LLC
- 当前专利权人地址: US TX Addison
- 代理机构: Vierra Magen Marcus LLP
- 主分类号: G11C16/26
- IPC分类号: G11C16/26 ; G11C16/04 ; G11C16/34 ; G11C16/30 ; G11C16/24 ; G11C16/10 ; G11C7/04 ; G11C11/56 ; G11C16/20 ; G11C29/02 ; G11C29/42
摘要:
Techniques are provided for improving the accuracy of read operations of memory cells, where the threshold voltage (Vth) of a memory cell can shift depending on when the read operation occurs. Countermeasures are provided for a first read situation in which a memory is read after a power on event or after a long delay since a last read. Read voltages of lower or higher programmed data states are set according to a positive or negative temperature coefficient (Tco), respectively. Read voltages for error recovery can be set similarly. In another aspect, a wait period between a dummy voltage and a read voltage is a function of temperature. In another aspect, word line voltages of unselected blocks are set according to a negative Tco. In another aspect, pass voltages are set based on a Tco for each programmed data state.
公开/授权文献
- US20170365349A1 Dynamic Tuning Of First Read Countermeasures 公开/授权日:2017-12-21
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