Patents by Inventor Ken Cheah

Ken Cheah has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10229744
    Abstract: Techniques are provided for improving the accuracy of read operations of memory cells, where the threshold voltage of the memory cells can shift depending on the coupled up state of the word lines. In one approach, for a read operation, a representative word line voltage in a block is detected and a corresponding set of read voltages is selected. In another approach, a pre-read voltage pulse is applied to a selected word line in response to a read command, just prior to reading the selected cells. In another approach, a voltage pulse is periodically applied to each word line in a block to provide the word lines in a coupled up state. In another approach, a soft erase is performed after a read operation to prevent coupling up of the word lines.
    Type: Grant
    Filed: November 17, 2017
    Date of Patent: March 12, 2019
    Assignee: SanDisk Technologies LLC
    Inventors: Deepanshu Dutta, Idan Alrod, Huai-Yuan Tseng, Amul Desai, Jun Wan, Ken Cheah, Sarath Puthenthermadam
  • Publication number: 20180254090
    Abstract: Techniques are provided for improving the accuracy of read operations of memory cells, where the threshold voltage of the memory cells can shift depending on the coupled up state of the word lines. In one approach, for a read operation, a representative word line voltage in a block is detected and a corresponding set of read voltages is selected. In another approach, a pre-read voltage pulse is applied to a selected word line in response to a read command, just prior to reading the selected cells. In another approach, a voltage pulse is periodically applied to each word line in a block to provide the word lines in a coupled up state. In another approach, a soft erase is performed after a read operation to prevent coupling up of the word lines.
    Type: Application
    Filed: November 17, 2017
    Publication date: September 6, 2018
    Applicant: SanDisk Technologies LLC
    Inventors: Deepanshu Dutta, Idan Alrod, Huai-Yuan Tseng, Amul Desai, Jun Wan, Ken Cheah, Sarath Puthenthermadam
  • Patent number: 10026486
    Abstract: Techniques are provided for improving the accuracy of read operations of memory cells, where the threshold voltage of the memory cells can shift depending on the coupled up state of the word lines. In one approach, for a read operation, a representative word line voltage in a block is detected and a corresponding set of read voltages is selected. In another approach, a pre-read voltage pulse is applied to a selected word line in response to a read command, just prior to reading the selected cells. In another approach, a voltage pulse is periodically applied to each word line in a block to provide the word lines in a coupled up state. In another approach, a soft erase is performed after a read operation to prevent coupling up of the word lines.
    Type: Grant
    Filed: March 6, 2017
    Date of Patent: July 17, 2018
    Assignee: SanDisk Technologies LLC
    Inventors: Deepanshu Dutta, Idan Alrod, Huai-Yuan Tseng, Amul Desai, Jun Wan, Ken Cheah, Sarath Puthenthermadam
  • Publication number: 20060168491
    Abstract: A method is discussed for providing programmable test conditions for a built-in self test circuit of a flash memory device. The method comprises providing a BIST interface adapted to adjust a test condition used in a BIST circuit, providing the memory cells of the Flash memory device, and providing the BIST circuit adapted to test the flash memory. The method further comprises communicating with the BIST interface one or more global variables associated with the test condition, adjusting the test condition used by the BIST circuit based on the values represented by the global variables, performing one or more test operations on the flash memory in accordance with the adjusted test condition, and reporting the results of the memory test operations. The method of the present invention may further include a serial communications medium and the use of a serial test protocol for communicating the global variables to the BIST interface and test results from the interface.
    Type: Application
    Filed: January 24, 2005
    Publication date: July 27, 2006
    Inventors: Mimi Lee, Darlene Hamilton, Ken Cheah, Kendra Nguyen, Xin Guo