Patents by Inventor Vishal Sarin

Vishal Sarin 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: 8976582
    Abstract: A memory device that includes a sample and hold circuit coupled to a bit line. The sample and hold circuit stores a target threshold voltage for a selected memory cell. The memory cell is programmed and then verified with a ramped read voltage. The read voltage that turns on the memory cell is stored in the sample and hold circuit. The target threshold voltage is compared with the read voltage by a comparator circuit. When the read voltage is at least substantially equal to (i.e., is substantially equal to and/or starts to exceed) the target threshold voltage, the comparator circuit generates an inhibit signal.
    Type: Grant
    Filed: February 11, 2011
    Date of Patent: March 10, 2015
    Assignee: Micron Technology, Inc.
    Inventors: Vishal Sarin, Jung-Sheng Hoei, Frankie F. Roohparvar
  • Patent number: 8953374
    Abstract: Methods and solid state drives are disclosed, for example a solid state drive that is adapted to receive and transmit analog data signals representative of bit patterns of three or more levels (such as to facilitate increases in data transfer rates relative to devices communicating data signals indicative of individual bits). Programming of the solid state drive, comprising an array of non-volatile memory cells, might include adjusting the level of each memory cell being programmed in response to a desired performance level of a controller circuit.
    Type: Grant
    Filed: December 16, 2013
    Date of Patent: February 10, 2015
    Assignee: Mircon Technology, Inc.
    Inventors: Frankie F. Roohparvar, Vishal Sarin, Jung-Sheng Hoei
  • Publication number: 20140376313
    Abstract: Apparatuses, current control circuits, and methods for limiting string current in a memory are described. An example apparatus includes a memory cell string including a memory cell. The example apparatus further includes a sense circuit configured to sense a current through the memory cell string, and a select gate configured to couple the memory cell string to a source based on a select gate voltage. The example apparatus further includes a current control circuit coupled to the select gate. The current control circuit is configured to limit current through the memory cell string during a memory access operation based on a reference current.
    Type: Application
    Filed: June 21, 2013
    Publication date: December 25, 2014
    Inventor: Vishal Sarin
  • Publication number: 20140351663
    Abstract: Memory devices and methods of operating memory devices are shown. Configurations described include circuits to perform a single check between programming pulses to determine a threshold voltage with respect to desired benchmark voltages. In one example, the benchmark voltages are used to change a programming speed of selected memory cells.
    Type: Application
    Filed: April 28, 2014
    Publication date: November 27, 2014
    Applicant: Micron Technology, Inc.
    Inventors: Vishal Sarin, Aaron Yip, Tomoharu Tanaka
  • Publication number: 20140298088
    Abstract: Methods for managing data stored in a memory device facilitate managing utilization of memory of different densities. The methods include reading first data from a first number of pages or blocks of memory cells having a first density, performing a data handling operation on the read first data to generate second data, and writing the second data to a second number of pages or blocks of memory cells having a second density, wherein the second density is different than the first density, and wherein the second number is different than the first number.
    Type: Application
    Filed: June 18, 2014
    Publication date: October 2, 2014
    Applicant: MICRON TECHNOLOGY, INC.
    Inventors: William H. Radke, Vishal Sarin, Jung-Sheng Hoei
  • Publication number: 20140237326
    Abstract: Methods and apparatus are disclosed, such as those involving a flash memory device that includes an array of memory cells. One such method includes detecting values of charges stored in selected memory cells in the memory cell array. The method also includes processing the detected values in accordance with a Viterbi algorithm so as to determine data stored in the selected memory cells. In one embodiment, the flash memory cell array includes word lines and bit lines. Detecting the values of charges includes detecting values of charges stored in a selected row of memory cells by selecting one of the word lines. The Viterbi algorithm provides correct data where inter-signal interference between the cells affects the accuracy of read data. For example, the Viterbi algorithm can be used to supplement error correction codes (ECC).
    Type: Application
    Filed: April 4, 2014
    Publication date: August 21, 2014
    Applicant: MICRON TECHNOLOGY, INC.
    Inventors: Frankie Roohparvar, Vishal Sarin, William Radke
  • Publication number: 20140204693
    Abstract: In an embodiment, a defective memory block is replaced with a non-defective memory block, and a voltage-delay correction is applied to the non-defective memory block that replaces the defective memory block based on the actual location of the non-defective memory block.
    Type: Application
    Filed: March 25, 2014
    Publication date: July 24, 2014
    Applicant: MICRON TECHNOLOGY, INC.
    Inventors: Vishal Sarin, Dzung H. Nguyen, William H. Radke
  • Patent number: 8787103
    Abstract: An analog-to-digital conversion window is defined by reference voltages stored in reference memory cells of a memory device. A first reference voltage is read to define an upper limit of the conversion window and a second reference voltage is read to define a lower limit of the conversion window. An analog voltage representing a digital bit pattern is read from a memory cell and converted to the digital bit pattern by an analog-to-digital conversion process using the conversion window as the limits for the sampling process. This scheme helps in real time tracking of the ADC window with changes in the program window of the memory array.
    Type: Grant
    Filed: July 21, 2011
    Date of Patent: July 22, 2014
    Assignee: Micron Technology, Inc.
    Inventors: Vishal Sarin, Jung-Sheng Hoei, Frankie F. Roohparvar
  • Patent number: 8773912
    Abstract: Methods of programming memory cells are disclosed. In at least one embodiment, programming is accomplished by applying a first set of programming pulses to program to an initial threshold voltage, and applying a second set of programming pulses to program to a final threshold voltage.
    Type: Grant
    Filed: July 12, 2012
    Date of Patent: July 8, 2014
    Assignee: Micron Technology, Inc.
    Inventors: Vishal Sarin, Frankie F. Roohparvar, Jung-Sheng Hoei, Jonathan Pabustan
  • Patent number: 8762629
    Abstract: Methods and apparatus for managing data storage in memory devices utilizing memory arrays of varying density memory cells. Data can be initially stored in lower density memory. Data can be further read, compacted, conditioned and written to higher density memory as background operations. Methods of data conditioning to improve data reliability during storage to higher density memory and methods for managing data across multiple memory arrays are also disclosed.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: June 24, 2014
    Assignee: Micron Technology, Inc.
    Inventors: William H. Radke, Vishal Sarin, Jung-Sheng Hoei
  • Patent number: 8737127
    Abstract: A memory controller has a digital signal processor. The digital signal processor is configured to output a digital data signal of M+N bits of program data intended for programming a memory cell of a memory device. The digital signal processor is configured to receive a digital data signal of M+L bits read from the memory cell of the memory device and to retrieve from the received digital data signal M bits of data that were stored in the memory cell.
    Type: Grant
    Filed: February 19, 2013
    Date of Patent: May 27, 2014
    Assignee: Micron Technology, Inc.
    Inventors: Vishal Sarin, Jung-Sheng Hoei, Jonathan Pabustan, Frankie F. Roohparvar
  • Patent number: 8719665
    Abstract: Memory devices that, in a particular embodiment, receive and transmit analog data signals representative of bit patterns of two or more bits such as to facilitate increases in data transfer rates relative to devices communicating data signals indicative of individual bits. Programming error correction code (ECC) and metadata into such memory devices includes storing the ECC and metadata at different bit levels per cell based on an actual error rate of the cells. The ECC and metadata can be stored with the data block at a different bit level than the data block. If the area of memory in which the block of data is stored does not support the desired reliability for the ECC and metadata at a particular bit level, the ECC and metadata can be stored in other areas of the memory array at different bit levels.
    Type: Grant
    Filed: October 17, 2013
    Date of Patent: May 6, 2014
    Assignee: Micron Technology, Inc.
    Inventors: Frankie F. Roohparvar, Vishal Sarin, Jung S. Hoei
  • Patent number: 8719680
    Abstract: Methods and apparatus are disclosed related to a memory device, such as a flash memory device that includes an array of memory cells. One such method includes detecting values of charges stored in selected memory cells in the memory cell array. The method also includes processing the detected values in accordance with a Viterbi algorithm so as to determine data stored in the selected memory cells. In one embodiment, the flash memory cell array includes word lines and bit lines. Detecting the values of charges includes detecting values of charges stored in a selected row of memory cells by selecting one of the word lines. The Viterbi algorithm provides correct data where inter-signal interference between the cells affects the accuracy of read data.
    Type: Grant
    Filed: June 27, 2013
    Date of Patent: May 6, 2014
    Assignee: Micron Technology, Inc.
    Inventors: Frankie Roohparvar, Vishal Sarin, William Radke
  • Patent number: 8713246
    Abstract: In one or more embodiments, a memory device has an adjustable programming window with a plurality of programmable levels. The programming window is moved to compensate for changes in reliable program and erase thresholds achievable as the memory device experiences factors such as erase/program cycles that change the program window. The initial programming window is determined prior to an initial erase/program cycle. The programming levels are then moved as the programming window changes, such that the plurality of programmable levels still remain within the program window and are tracked with the program window changes.
    Type: Grant
    Filed: September 7, 2012
    Date of Patent: April 29, 2014
    Assignee: Micron Technology, Inc.
    Inventors: Vishal Sarin, Frankie F. Roohparvar, Jonathan Pabustan, Jung-Sheng Hoei
  • Patent number: 8711616
    Abstract: Memory devices and methods of operating memory devices are shown. Configurations described include circuits to perform a single check between programming pulses to determine a threshold voltage with respect to desired benchmark voltages. In one example, the benchmark voltages are used to change a programming speed of selected memory cells.
    Type: Grant
    Filed: December 22, 2010
    Date of Patent: April 29, 2014
    Assignee: Micron Technology, Inc.
    Inventors: Vishal Sarin, Aaron Yip, Tomoharu Tanaka
  • Patent number: 8707112
    Abstract: In one or more of the disclosed embodiments, memory cells in a memory device are refreshed upon an indication of a fatigue condition. In one such embodiment, controller monitors behavior parameters of the cells and determines if any of the parameters are outside of a normal range set for each one, thus indicating a fatigue condition. If any cell indicates a fatigue condition, the data from the block of cells indicating the fatigue is moved to another block. In one embodiment, an error detection and correction process is performed on the data prior to being written into another memory block.
    Type: Grant
    Filed: October 13, 2011
    Date of Patent: April 22, 2014
    Assignee: Micron Technology, Inc.
    Inventors: Frankie F. Roohparvar, Vishal Sarin, Jung-Sheng Hoei
  • Patent number: 8705299
    Abstract: An apparatus has a controller. The controller is configured to address a non-defective memory block of a sequence of memory blocks in place of a defective memory block of the sequence of memory blocks such that the non-defective memory block replaces the defective memory block. The non-defective memory block is a proximate non-defective memory block following the defective memory block in the sequence of memory blocks that is available to replace the defective memory block. The controller is configured to apply a voltage-delay correction to the non-defective memory block that replaces the defective memory block based on the actual location of the non-defective memory block.
    Type: Grant
    Filed: May 15, 2013
    Date of Patent: April 22, 2014
    Assignee: Micron Technology, Inc.
    Inventors: Vishal Sarin, Dzung H. Nguyen, William H. Radke
  • Publication number: 20140104958
    Abstract: Methods of programming a memory and memories are disclosed. In at least one embodiment, a memory is programmed by determining a pretarget threshold voltage for a selected cell, wherein the pretarget threshold voltage is determined using pretarget threshold voltage values for at least one neighbor cell of the selected cell.
    Type: Application
    Filed: December 17, 2013
    Publication date: April 17, 2014
    Applicant: Micron Technology, Inc.
    Inventors: Vishal SARIN, William H. RADKE, Frankie F. ROOHPARVAR
  • Publication number: 20140104944
    Abstract: Methods and solid state drives are disclosed, for example a solid state drive that is adapted to receive and transmit analog data signals representative of bit patterns of three or more levels (such as to facilitate increases in data transfer rates relative to devices communicating data signals indicative of individual bits). Programming of the solid state drive, comprising an array of non-volatile memory cells, might include adjusting the level of each memory cell being programmed in response to a desired performance level of a controller circuit.
    Type: Application
    Filed: December 16, 2013
    Publication date: April 17, 2014
    Applicant: Micron Technology, Inc.
    Inventors: Frankie F. ROOHPARVAR, Vishal SARIN, Jung-Sheng HOEI
  • Publication number: 20140104956
    Abstract: Methods for sensing, method for programming, memory devices, and memory systems are disclosed. In one such method for sensing, a counting circuit generates a count output and a translated count output. The count output is converted into a time varying voltage that biases a word line coupled to memory cells being sensed. Target data for each memory cell is stored in a data cache associated with that particular memory cell. When it is detected that a memory cell has turned on, the translated count output associated with the count output that is indicative of the voltage level that turned on the memory cell is compared to the target data. The comparison determines the state of the memory cell.
    Type: Application
    Filed: December 12, 2013
    Publication date: April 17, 2014
    Applicant: MICRON TECHNOLOGY, INC.
    Inventors: Jonathan Pabustan, Vishal Sarin, Dzung H. Nguyen