Patents by Inventor Zac Shepard

Zac Shepard 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: 8995183
    Abstract: In a nonvolatile memory that stores data in two or more different data storage formats, such as binary and MLC, a separation scheme is used to distribute blocks containing data in one data storage format (e.g. binary) so that they are separated by at least some minimum number of blocks using another data storage format (e.g. MLC).
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: March 31, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Zac Shepard, Steven T. Sprouse, Chris Nga Yee Avila
  • Patent number: 8732391
    Abstract: In a nonvolatile memory array, blocks that contain only obsolete data are modified by adding charge to their cells, increasing the charge level from the programmed charge levels that represented obsolete data to elevated charge levels. The increase in overall charge in such blocks lessens the tendency of such blocks to impact data retention in neighboring blocks.
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: May 20, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Zac Shepard, Steven T. Sprouse, Chris Nga Yee Avila, Neil David Hutchison
  • Publication number: 20130279248
    Abstract: In a nonvolatile memory that stores data in two or more different data storage formats, such as binary and MLC, a separation scheme is used to distribute blocks containing data in one data storage format (e.g. binary) so that they are separated by at least some minimum number of blocks using another data storage format (e.g. MLC).
    Type: Application
    Filed: April 23, 2012
    Publication date: October 24, 2013
    Inventors: Zac Shepard, Steven T. Sprouse, Chris Nga Yee Avila
  • Publication number: 20130282958
    Abstract: In a nonvolatile memory array, blocks that contain only obsolete data are modified by adding charge to their cells, increasing the charge level from the programmed charge levels that represented obsolete data to elevated charge levels. The increase in overall charge in such blocks lessens the tendency of such blocks to impact data retention in neighboring blocks.
    Type: Application
    Filed: April 23, 2012
    Publication date: October 24, 2013
    Inventors: Zac Shepard, Steven T. Sprouse, Chris Nga Yee Avila, Neil David Hutchison
  • Patent number: 8179717
    Abstract: A non-volatile memory chip package is prepared for surface mounting to a substrate in a solder reflow process by programming erased blocks to higher threshold voltage levels, to improve data retention for blocks which are preloaded with content, such as by an electronic device manufacturer. Following the surface mounting, the previously-erased blocks are returned to the erased state. The threshold voltage of storage elements of the preloaded blocks can change during the surface mounting process due to a global charge effect phenomenon. The effect is most prominent for higher state storage elements which are surrounded by erased blocks, in a chip for which the wafer backside was thinned and polished. The erased blocks can be programmed using a single program pulse without performing a verify operation, as a wide threshold voltage distribution is acceptable.
    Type: Grant
    Filed: September 29, 2009
    Date of Patent: May 15, 2012
    Assignee: SanDisk Technologies Inc.
    Inventors: Zac Shepard, Xiaoyu Yang, Albert Meeks, Qing Li, Enosh Levi, Kim Le, Raz Dan, Brian Murphy
  • Publication number: 20110075482
    Abstract: A non-volatile memory chip package is prepared for surface mounting to a substrate in a solder reflow process by programming erased blocks to higher threshold voltage levels, to improve data retention for blocks which are preloaded with content, such as by an electronic device manufacturer. Following the surface mounting, the previously-erased blocks are returned to the erased state. The threshold voltage of storage elements of the preloaded blocks can change during the surface mounting process due to a global charge effect phenomenon. The effect is most prominent for higher state storage elements which are surrounded by erased blocks, in a chip for which the wafer backside was thinned and polished. The erased blocks can be programmed using a single program pulse without performing a verify operation, as a wide threshold voltage distribution is acceptable.
    Type: Application
    Filed: September 29, 2009
    Publication date: March 31, 2011
    Inventors: Zac Shepard, Xiaoyu Yang, Albert Meeks, Qing Li, Enosh Levi, Kim Le, Raz Dan, Brian Murphy