Patents by Inventor Jayaprakash Naradasi

Jayaprakash Naradasi 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).

  • Publication number: 20230288949
    Abstract: Various embodiments of the present disclosure relate to apparatuses and methods for regulators providing shared current from multiple input supplies. A regulator can include a first portion configured to receive a first supply voltage and to output a first current drawn from the first supply voltage by a load, and a second portion configured to receive a second supply voltage. The regulator can include a current control circuit configured to, responsive to a load current corresponding the load meeting a particular criteria, initiate current sharing such that the load current is subsequently shared between the first supply voltage and the second supply voltage.
    Type: Application
    Filed: July 28, 2022
    Publication date: September 14, 2023
    Inventors: Ekram H. Bhuiyan, Jayaprakash Naradasi, Srinivasa Rao Sabbineni, Michael Mostovoy
  • Patent number: 10129012
    Abstract: A non-source-synchronous system may include a clock-sending device and a clock-receiving device that communicate via a communications bus. The clock-sending device and the clock-receiving device may perform a tuning operation, in which the clock-receiving device sends one or more data signals on one or more data lines of the communications bus to the clock-sending device. The clock-sending device may delay its internal clock signal by an amount based on the one or more data signals. The clock-sending device may then perform sampling of data signals received from the clock-receiving device based on the tuning operation. The tuning operation may be performed in accordance with SDR or DDR, and thus allow for SDR or DDR communication with optimal sampling for systems that do not use a data strobe.
    Type: Grant
    Filed: March 29, 2017
    Date of Patent: November 13, 2018
    Assignee: SanDisk Technologies LLC
    Inventors: Krishnamurthy Dhakshinamurthy, Shajith Musaliar Sirajudeen, Jayaprakash Naradasi, Bhavin Odedara, Yosi Pinto, Rampraveen Somasundaram, Anand Sharma
  • Publication number: 20180083764
    Abstract: A non-source-synchronous system may include a clock-sending device and a clock-receiving device that communicate via a communications bus. The clock-sending device and the clock-receiving device may perform a tuning operation, in which the clock-receiving device sends one or more data signals on one or more data lines of the communications bus to the clock-sending device. The clock-sending device may delay its internal clock signal by an amount based on the one or more data signals. The clock-sending device may then perform sampling of data signals received from the clock-receiving device based on the tuning operation. The tuning operation may be performed in accordance with SDR or DDR, and thus allow for SDR or DDR communication with optimal sampling for systems that do not use a data strobe.
    Type: Application
    Filed: March 29, 2017
    Publication date: March 22, 2018
    Applicant: SanDisk Technologies LLC
    Inventors: Krishnamurthy Dhakshinamurthy, Shajith Musaliar Sirajudeen, Jayaprakash Naradasi, Bhavin Odedara, Yosi Pinto, Rampraveen Somasundaram, Anand Sharma
  • Patent number: 9660656
    Abstract: Methods and circuits for delay compensation are provided. A data clock may be generated from a peripheral clock. Sample data may be provided in a data signal on a bus in response to an edge of the data clock, where the edge of the data clock is triggered by an initial edge of the peripheral clock. A delay of the data clock relative to the peripheral clock may be selected based on a time difference between the initial edge of the peripheral clock and a time at which the sample data is detected on the bus. A delayed data clock having the selected delay relative to the peripheral clock may be generated. Requested data may be provided on the bus in response to an edge of the delayed data clock.
    Type: Grant
    Filed: April 15, 2015
    Date of Patent: May 23, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Ramakrishnan Karungulam Subramanian, Anand Venkitachalam, Jayaprakash Naradasi, Prashant Singhal
  • Publication number: 20160308540
    Abstract: Methods and circuits for delay compensation are provided. A data clock may be generated from a peripheral clock. Sample data may be provided in a data signal on a bus in response to an edge of the data clock, where the edge of the data clock is triggered by an initial edge of the peripheral clock. A delay of the data clock relative to the peripheral clock may be selected based on a time difference between the initial edge of the peripheral clock and a time at which the sample data is detected on the bus. A delayed data clock having the selected delay relative to the peripheral clock may be generated. Requested data may be provided on the bus in response to an edge of the delayed data clock.
    Type: Application
    Filed: April 15, 2015
    Publication date: October 20, 2016
    Inventors: Ramakrishnan Karungulam Subramanian, Anand Venkitachalam, Jayaprakash Naradasi, Prashant Singhal
  • Patent number: 9349489
    Abstract: A data storage device includes non-volatile memory and a controller. The controller is configured to, at a first time, determine a first count of storage elements having threshold voltages within a voltage range that corresponds to a first reference voltage. The controller is further configured to, at a second time, determine a second count of storage elements having threshold voltages within the voltage range. The controller is further configured to calculate an updated first reference voltage at least partially based on the first reference voltage, the first count, and the second count.
    Type: Grant
    Filed: February 20, 2013
    Date of Patent: May 24, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Sateesh Desireddi, Jayaprakash Naradasi, Anand Venkitachalam, Manuel Antonio D'Abreu, Stephen Skala
  • Patent number: 9318215
    Abstract: A data storage device includes non-volatile memory and a controller. The controller is configured to read first data from the non-volatile memory. The first data indicates a first count of storage elements of the group that have a first activation status when sensed with a first reference voltage at a first time. The controller is configured to read second data from the non-volatile memory. The second data indicates a second count of storage elements of the group that have the first activation status when sensed with the first reference voltage at a second time. The controller is configured to generate an updated first reference voltage at least partially based on a difference between the first count and the second count and based on one or more parameters corresponding to a distribution of threshold voltages of storage elements at the first time.
    Type: Grant
    Filed: April 11, 2013
    Date of Patent: April 19, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Sateesh Desireddi, Sachin Krishne Gowda, Jayaprakash Naradasi, Anand Venkitachalam, Manuel Antonio D'Abreu, Stephen Skala
  • Patent number: 8874992
    Abstract: In a data storage device that includes a non-volatile memory, a method includes determining that a current error correction code page count (CEC) is at least as large as a target error correction code page count (TEC). The CEC is a page count of error correction code (ECC) pages of data read from the memory during a time period from a previous time to a particular time using a set of reference voltages. In response to the CEC being at least as large as the TEC, the method includes updating a subset of the set of reference voltages conditioned upon a difference between a current mean error count (CMEC) and a previous mean error count being at least as large as a target mean delta error. The CMEC is based on a count of read errors associated with the ECC pages read during the time period.
    Type: Grant
    Filed: September 28, 2012
    Date of Patent: October 28, 2014
    Assignee: Sandisk Technologies Inc.
    Inventors: Sateesh Desireddi, Jayaprakash Naradasi, Anand Venkitachalam, Manuel Antonio D'Abreu, Stephen Skala
  • Patent number: 8811076
    Abstract: A method includes, in a data storage device that includes a non-volatile memory, selecting an updated reference voltage as one of a reference voltage, a first alternate reference voltage and a second alternate reference voltage. The first alternate reference voltage and the second alternate reference voltage are calculated based on the reference voltage and based on a voltage increment. Selection of the updated reference voltage is based on a comparison of error counts, each error count associated with a unique one of the reference voltage, the first alternate reference voltage, and the second alternate reference voltage. The method includes resetting the reference voltage to the updated reference voltage, resetting the voltage increment to a reset voltage increment that is smaller than the voltage increment, and selecting an additional updated reference voltage based on the reset reference voltage and based on the reset voltage increment.
    Type: Grant
    Filed: August 30, 2012
    Date of Patent: August 19, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Anand Venkitachalam, Sateesh Desireddi, Jayaprakash Naradasi, Manuel Antonio D'Abreu, Stephen Skala
  • Publication number: 20140226398
    Abstract: A data storage device includes non-volatile memory and a controller. The controller is configured to read first data from the non-volatile memory. The first data indicates a first count of storage elements of the group that have a first activation status when sensed with a first reference voltage at a first time. The controller is configured to read second data from the non-volatile memory. The second data indicates a second count of storage elements of the group that have the first activation status when sensed with the first reference voltage at a second time. The controller is configured to generate an updated first reference voltage at least partially based on a difference between the first count and the second count and based on one or more parameters corresponding to a distribution of threshold voltages of storage elements at the first time.
    Type: Application
    Filed: April 11, 2013
    Publication date: August 14, 2014
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: SATEESH DESIREDDI, SACHIN KRISHNE GOWDA, JAYAPRAKASH NARADASI, ANAND VENKITACHALAM, MANUEL ANTONIO D'ABREU, STEPHEN SKALA
  • Publication number: 20140201580
    Abstract: A data storage device includes non-volatile memory and a controller. The controller is configured to, at a first time, determine a first count of storage elements having threshold voltages within a voltage range that corresponds to a first reference voltage. The controller is further configured to, at a second time, determine a second count of storage elements having threshold voltages within the voltage range. The controller is further configured to calculate an updated first reference voltage at least partially based on the first reference voltage, the first count, and the second count.
    Type: Application
    Filed: February 20, 2013
    Publication date: July 17, 2014
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: SATEESH DESIREDDI, JAYAPRAKASH NARADASI, ANAND VENKITACHALAM, MANUEL ANTONIO D'ABREU, STEPHEN SKALA
  • Patent number: 8669817
    Abstract: A technique and corresponding circuitry are presented for a process independent, self-calibrating relaxation based clock source. The technique and circuitry presented here can reduce the time and cost needed for calibration significantly. The relaxation based clock source produces a clock signal whose frequency is dependent upon a trim value. Starting from an initial trim value, the clock signal is generated, its frequency is compared with a reference clock frequency value, and the trim value is correspondingly adjusted up or down a bit at a time. After this process has continued for a while, min-max logic is used to determine the maximum and minimum trim values and, based on these, the final trim value for the clock is set. This calibration process can also be used to extract whether, and by how much, the implementation on silicon of a particular chip lies in the fast or slow process corners.
    Type: Grant
    Filed: November 21, 2011
    Date of Patent: March 11, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Deepak Pancholi, Bhavin Odedara, Naidu Prasad, Srikanth Bojja, Srinivasa Rao Sabbineni, Jayaprakash Naradasi
  • Publication number: 20140068382
    Abstract: In a data storage device that includes a non-volatile memory, a method includes determining that a current error correction code page count (CEC) is at least as large as a target error correction code page count (TEC). The CEC is a page count of error correction code (ECC) pages of data read from the memory during a time period from a previous time to a particular time using a set of reference voltages. In response to the CEC being at least as large as the TEC, the method includes updating a subset of the set of reference voltages conditioned upon a difference between a current mean error count (CMEC) and a previous mean error count being at least as large as a target mean delta error. The CMEC is based on a count of read errors associated with the ECC pages read during the time period.
    Type: Application
    Filed: September 28, 2012
    Publication date: March 6, 2014
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: SATEESH DESIREDDI, JAYAPRAKASH NARADASI, ANAND VENKITACHALAM, MANUEL ANTONIO D'ABREU, STEPHEN SKALA
  • Publication number: 20140029336
    Abstract: A method includes, in a data storage device that includes a non-volatile memory, selecting an updated reference voltage as one of a reference voltage, a first alternate reference voltage and a second alternate reference voltage. The first alternate reference voltage and the second alternate reference voltage are calculated based on the reference voltage and based on a voltage increment. Selection of the updated reference voltage is based on a comparison of error counts, each error count associated with a unique one of the reference voltage, the first alternate reference voltage, and the second alternate reference voltage. The method includes resetting the reference voltage to the updated reference voltage, resetting the voltage increment to a reset voltage increment that is smaller than the voltage increment, and selecting an additional updated reference voltage based on the reset reference voltage and based on the reset voltage increment.
    Type: Application
    Filed: August 30, 2012
    Publication date: January 30, 2014
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: ANAND VENKITACHALAM, SATEESH DESIREDDI, JAYAPRAKASH NARADASI, MANUEL ANTONIO D'ABREU, STEPHEN SKALA
  • Patent number: 8605502
    Abstract: A method includes, in a data storage device that includes a non-volatile memory, reading first data values from memory elements of the non-volatile memory using a set of reference voltages that includes a first reference voltage, and determining a first error count associated with the first reference voltage. The method includes reading second data values from the group of memory elements using a set of modified reference voltages that includes a modified first reference voltage, and determining a modified error count associated with the modified first reference voltage. The method includes updating the set of reference voltages to include the first reference voltage or the modified first reference voltage based on a comparison of the error count to the modified error count.
    Type: Grant
    Filed: June 14, 2012
    Date of Patent: December 10, 2013
    Assignee: Sandisk Technologies Inc.
    Inventors: Sateesh Desireddi, Jayaprakash Naradasi, Anand Venkitachalam
  • Publication number: 20130314988
    Abstract: A method includes, in a data storage device that includes a non-volatile memory, reading first data values from memory elements of the non-volatile memory using a set of reference voltages that includes a first reference voltage, and determining a first error count associated with the first reference voltage. The method includes reading second data values from the group of memory elements using a set of modified reference voltages that includes a modified first reference voltage, and determining a modified error count associated with the modified first reference voltage. The method includes updating the set of reference voltages to include the first reference voltage or the modified first reference voltage based on a comparison of the error count to the modified error count.
    Type: Application
    Filed: June 14, 2012
    Publication date: November 28, 2013
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: SATEESH DESIREDDI, JAYAPRAKASH NARADASI, ANAND VENKITACHALAM
  • Patent number: 8560919
    Abstract: A method in a data storage device with a memory includes receiving bit values to be stored at a set of cells of the memory and interleaving the received bit values to form multiple interleaved groups of data bits according to an adjustable parameter. The method also includes writing the multiple interleaved groups of data bits to the set of cells.
    Type: Grant
    Filed: February 21, 2011
    Date of Patent: October 15, 2013
    Assignee: SanDisk Technologies Inc.
    Inventors: Manuel Antonio D'Abreu, Stephen Skala, Jayaprakash Naradasi, Anand Venkitachalam
  • Patent number: 8392807
    Abstract: Systems and methods to perform distributive ECC operations are disclosed. A method includes, in a controller of a memory device, receiving data including a data block and main error correction coding (ECC) data for the data block. The data block includes a first sub-block of data and first ECC data corresponding to the first sub-block. The method includes initiating a data block ECC operation to process the data block using the main ECC data and initiating a sub-block ECC operation to process the first sub-block using the first ECC data. The method also includes selectively initiating an error location search of the data block ECC operation based on a result of the sub-block ECC operation.
    Type: Grant
    Filed: September 15, 2010
    Date of Patent: March 5, 2013
    Assignee: Sandisk Technologies Inc.
    Inventors: Jayaprakash Naradasi, Anand Venkitachalam
  • Publication number: 20120102379
    Abstract: A method in a data storage device with a memory includes receiving bit values to be stored at a set of cells of the memory and interleaving the received bit values to form multiple interleaved groups of data bits according to an adjustable parameter. The method also includes writing the multiple interleaved groups of data bits to the set of cells.
    Type: Application
    Filed: February 21, 2011
    Publication date: April 26, 2012
    Applicant: SANDISK CORPORATION
    Inventors: MANUEL ANTONIO D'ABREU, STEPHEN SKALA, JAYAPRAKASH NARADASI, ANAND VENKITACHALAM
  • Publication number: 20120062326
    Abstract: A technique and corresponding circuitry are presented for a process independent, self-calibrating relaxation based clock source. The technique and circuitry presented here can reduce the time and cost needed for calibration significantly. The relaxation based clock source produces a clock signal whose frequency is dependent upon a trim value. Starting from an initial trim value, the clock signal is generated, its frequency is compared with a reference clock frequency value, and the trim value is correspondingly adjusted up or down a bit at a time. After this process has continued for a while, min-max logic is used to determine the maximum and minimum trim values and, based on these, the final trim value for the clock is set. This calibration process can also be used to extract whether, and by how much, the implementation on silicon of a particular chip lies in the fast or slow process corners.
    Type: Application
    Filed: November 21, 2011
    Publication date: March 15, 2012
    Inventors: Deepak Pancholi, Bhavin Odedara, Naidu Prasad, Srikanth Bojja, Srinivasa Rao Sabbineni, Jayaprakash Naradasi