Patents by Inventor Viswanathan Nagarajan

Viswanathan Nagarajan 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: 11962318
    Abstract: In described examples, an analog to digital converter (ADC), having an input operable to receive an analog signal and an output operable to output a digital representation of the analog signal, includes a voltage to delay (VD) block. The VD block is coupled to the input of the ADC and generates a delay signal responsive to a calibration signal. A backend ADC is coupled to the VD block, and receives the delay signal. The backend ADC having multiple stages including a first stage. A calibration engine is coupled to the multiple stages and the VD block. The calibration engine measures an error count of the first stage and stores a delay value of the first stage for which the error count is minimum.
    Type: Grant
    Filed: January 5, 2022
    Date of Patent: April 16, 2024
    Assignee: Texas Instruments Incorporated
    Inventors: Himanshu Varshney, Viswanathan Nagarajan, Charls Babu, Narasimhan Rajagopal, Eeshan Miglani, Visvesvaraya A Pentakota
  • Patent number: 11955984
    Abstract: An analog-to-digital converter (ADC) includes: a set of comparators configured to provide comparison results based on an analog signal and respective reference thresholds for comparators of the set of comparators; digitization circuitry configured to provide a digital output code based on the comparison results and a mapping; and calibration circuitry. The calibration circuitry is configured to: receive the comparison results; determine if the analog signal is proximate to one of the respective reference thresholds based on the comparison results; in response to determining the analog signal is proximate to one of the respective reference thresholds, receive ADC values based on different pseudorandom binary sequence (PRBS) values being applied to the analog signal; determine an offset error based on the ADC values; and provide a comparator input offset calibration signal at a calibration circuitry output if the estimated offset error is greater than an offset error threshold.
    Type: Grant
    Filed: May 31, 2022
    Date of Patent: April 9, 2024
    Assignee: Texas Instruments Incorporated
    Inventors: Viswanathan Nagarajan, Aniket Datta, Nithin Gopinath
  • Patent number: 11881867
    Abstract: In described examples, a circuit includes a calibration engine. The calibration engine generates multiple input codes. A digital to analog converter (DAC) is coupled to the calibration engine, and generates a first calibration signal in response to a first input code of the multiple input codes. An analog to digital converter (ADC) is coupled to the DAC, and generates multiple raw codes responsive to the first calibration signal. A storage circuit is coupled to the ADC and stores a first output code corresponding to the first input code. The first output code is obtained using the multiple raw codes generated by the ADC.
    Type: Grant
    Filed: September 7, 2021
    Date of Patent: January 23, 2024
    Assignee: Texas Instruments Incorporated
    Inventors: Narasimhan Rajagopal, Eeshan Miglani, Chirag Chandrahas Shetty, Neeraj Shrivastava, Shagun Dusad, Srinivas Kumar Reddy Naru, Nithin Gopinath, Charls Babu, Shivam Srivastava, Viswanathan Nagarajan, Jagannathan Venkataraman, Harshit Moondra, Prasanth K, Visvesvaraya Appala Pentakota
  • Publication number: 20230387932
    Abstract: A circuit includes a nonlinear analog-to-digital converter (ADC) configured to provide a first digital output based on an analog input signal. The circuit also includes a linearization circuit having a lookup table (LUT) memory configured to store initial calibration data. The linearization circuit is coupled to the nonlinear ADC and is configured to: determine updated calibration data based on the initial calibration data; replace the initial calibration data in the LUT memory with the updated calibration data; and provide a second digital output at a linearization circuit output of the linearization circuit based on the first digital output and the updated calibration data.
    Type: Application
    Filed: May 26, 2022
    Publication date: November 30, 2023
    Inventors: Narasimhan RAJAGOPAL, Nithin GOPINATH, Viswanathan NAGARAJAN, Neeraj SHRIVASTAVA, Visvesvaraya A. PENTAKOTA, Harshit MOONDRA, Abhinav CHANDRA
  • Publication number: 20230387933
    Abstract: An analog-to-digital converter (ADC) includes: a set of comparators configured to provide comparison results based on an analog signal and respective reference thresholds for comparators of the set of comparators; digitization circuitry configured to provide a digital output code based on the comparison results and a mapping; and calibration circuitry. The calibration circuitry is configured to: receive the comparison results; determine if the analog signal is proximate to one of the respective reference thresholds based on the comparison results; in response to determining the analog signal is proximate to one of the respective reference thresholds, receive ADC values based on different pseudorandom binary sequence (PRBS) values being applied to the analog signal; determine an offset error based on the ADC values; and provide a comparator input offset calibration signal at a calibration circuitry output if the estimated offset error is greater than an offset error threshold.
    Type: Application
    Filed: May 31, 2022
    Publication date: November 30, 2023
    Inventors: Viswanathan NAGARAJAN, Aniket DATTA, Nithin GOPINATH
  • Publication number: 20220247420
    Abstract: In described examples, a circuit includes a calibration engine. The calibration engine generates multiple input codes. A digital to analog converter (DAC) is coupled to the calibration engine, and generates a first calibration signal in response to a first input code of the multiple input codes. An analog to digital converter (ADC) is coupled to the DAC, and generates multiple raw codes responsive to the first calibration signal. A storage circuit is coupled to the ADC and stores a first output code corresponding to the first input code. The first output code is obtained using the multiple raw codes generated by the ADC.
    Type: Application
    Filed: September 7, 2021
    Publication date: August 4, 2022
    Inventors: Narasimhan Rajagopal, Eeshan Miglani, Chirag Chandrahas Shetty, Neeraj Shrivastava, Shagun Dusad, Srinivas Kumar Reddy Naru, Nithin Gopinath, Charls Babu, Shivam Srivastava, Viswanathan Nagarajan, Jagannathan Venkataraman, Harshit Moondra, Prasanth K, Visvesvaraya Appala Pentakota
  • Publication number: 20220224349
    Abstract: In described examples, an analog to digital converter (ADC), having an input operable to receive an analog signal and an output operable to output a digital representation of the analog signal, includes a voltage to delay (VD) block. The VD block is coupled to the input of the ADC and generates a delay signal responsive to a calibration signal. A backend ADC is coupled to the VD block, and receives the delay signal. The backend ADC having multiple stages including a first stage. A calibration engine is coupled to the multiple stages and the VD block. The calibration engine measures an error count of the first stage and stores a delay value of the first stage for which the error count is minimum.
    Type: Application
    Filed: January 5, 2022
    Publication date: July 14, 2022
    Inventors: Himanshu Varshney, Viswanathan Nagarajan, Charls Babu, Narasimhan Rajagopal, Eeshan Miglani, Visvesvaraya A. Pentakota
  • Patent number: 11309902
    Abstract: In described examples, a stochastic comparator includes a first comparator that compares an input signal and a primary threshold to generate a first signal. A second comparator compares the input signal and the primary threshold to generate a second signal. A decision block generates a control signal in response to the first signal, the second signal and a PRBS (pseudo random binary sequence) signal. A XOR gate generates a detection signal in response the first signal and the second signal.
    Type: Grant
    Filed: December 16, 2019
    Date of Patent: April 19, 2022
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Srinivas Kumar Reddy Naru, Narasimhan Rajagopal, Shagun Dusad, Viswanathan Nagarajan, Visvesvaraya Appala Pentakota
  • Publication number: 20200119743
    Abstract: In described examples, a stochastic comparator includes a first comparator that compares an input signal and a primary threshold to generate a first signal. A second comparator compares the input signal and the primary threshold to generate a second signal. A decision block generates a control signal in response to the first signal, the second signal and a PRBS (pseudo random binary sequence) signal. A XOR gate generates a detection signal in response the first signal and the second signal.
    Type: Application
    Filed: December 16, 2019
    Publication date: April 16, 2020
    Inventors: Srinivas Kumar Reddy NARU, Narasimhan RAJAGOPAL, Shagun DUSAD, Viswanathan NAGARAJAN, Visvesvaraya Appala PENTAKOTA
  • Patent number: 10581406
    Abstract: A circuit for digital filtering an analog signal converted to digital, including an analog circuit to generate an analog signal, the analog signal including phase and/or gain errors. An analog-to-digital converter (ADC) to convert the analog signal to a digital signal output to a digital signal path. A frequency-dependent corrector filter included in the digital signal path, and configured as a parameterized filter, the parameterized filter configurable based on the DSA control signal with at least one complex filter parameter for each DSA attenuation step, to correct frequency-dependent errors in phase and/or gain.
    Type: Grant
    Filed: June 11, 2018
    Date of Patent: March 3, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Jawaharlal Tangudu, Karthik Khanna S, Chandrasekhar Sriram, Rajendrakumar Joish, Viswanathan Nagarajan
  • Patent number: 10541700
    Abstract: In described examples, a stochastic comparator includes a first comparator that compares an input signal and a primary threshold to generate a first signal. A second comparator compares the input signal and the primary threshold to generate a second signal. A decision block generates a control signal in response to the first signal, the second signal and a PRBS (pseudo random binary sequence) signal. A XOR gate generates a detection signal in response the first signal and the second signal.
    Type: Grant
    Filed: January 16, 2019
    Date of Patent: January 21, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Srinivas Kumar Reddy Naru, Narasimhan Rajagopal, Shagun Dusad, Viswanathan Nagarajan, Visvesvaraya Appala Pentakota
  • Patent number: 10419036
    Abstract: A pipeline ADC comprising an ADC segment and a digital backend coupled to the ADC segment. In some examples the ADC is configured to receive an analog signal, generate a first partial digital code representing a first sample of the analog signal, and generate a second partial digital code representing a second sample of the analog signal. In some examples the digital backend is configured to receive the first and second partial digital codes from the ADC segment, generate a combined digital code based at least partially on the first and second partial digital codes, determine a gain error of the ADC segment based at least partially on a first correlation of a PRBS with a difference between the first and second partial digital codes, and apply a first correction to the combined digital code based at least partially on the gain error of the ADC segment.
    Type: Grant
    Filed: September 10, 2018
    Date of Patent: September 17, 2019
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Viswanathan Nagarajan, Srinivas Kumar Reddy Naru, Narasimhan Rajagopal
  • Publication number: 20190280703
    Abstract: In described examples, a stochastic comparator includes a first comparator that compares an input signal and a primary threshold to generate a first signal. A second comparator compares the input signal and the primary threshold to generate a second signal. A decision block generates a control signal in response to the first signal, the second signal and a PRBS (pseudo random binary sequence) signal. A XOR gate generates a detection signal in response the first signal and the second signal.
    Type: Application
    Filed: January 16, 2019
    Publication date: September 12, 2019
    Inventors: Srinivas Kumar Reddy NARU, Narasimhan RAJAGOPAL, Shagun DUSAD, Viswanathan NAGARAJAN, Visvesvaraya Appala PENTAKOTA
  • Patent number: 10320405
    Abstract: In described examples, an analog to digital converter (ADC) includes a flash ADC. The flash ADC generates a flash output in response to an input signal, and an error correction block generates a known pattern. A selector block is coupled to the flash ADC and the error correction block, and generates a plurality of selected signals in response to the flash output and the known pattern. A digital to analog converter (DAC) is coupled to the selector block, and generates a coarse analog signal in response to the plurality of selected signals. A residue amplifier is coupled to the DAC, and generates a residual analog signal in response to the coarse analog signal, the input signal and an analog PRBS (pseudo random binary sequence) signal. A residual ADC generates a residual code in response to the residual analog signal.
    Type: Grant
    Filed: March 1, 2018
    Date of Patent: June 11, 2019
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Srinivas Kumar Reddy Naru, Visvesvaraya Pentakota Appala, Shagun Dusad, Neeraj Shrivastava, Viswanathan Nagarajan, Ani Xavier, Rishi Soundararajan, Sai Aditya Nurani, Roswald Francis
  • Publication number: 20190013795
    Abstract: A circuit for digital filtering an analog signal converted to digital, including an analog circuit to generate an analog signal, the analog signal including phase and/or gain errors. An analog-to-digital converter (ADC) to convert the analog signal to a digital signal output to a digital signal path. A frequency-dependent corrector filter included in the digital signal path, and configured as a parameterized filter, the parameterized filter configurable based on the DSA control signal with at least one complex filter parameter for each DSA attenuation step, to correct frequency-dependent errors in phase and/or gain.
    Type: Application
    Filed: June 11, 2018
    Publication date: January 10, 2019
    Inventors: Jawaharlal Tangudu, KARTHIK KHANNA S, Chandrasekhar Sriram, Rajendrakumar Joish, Viswanathan Nagarajan
  • Publication number: 20190007071
    Abstract: A pipeline ADC comprising an ADC segment and a digital backend coupled to the ADC segment. In some examples the ADC is configured to receive an analog signal, generate a first partial digital code representing a first sample of the analog signal, and generate a second partial digital code representing a second sample of the analog signal. In some examples the digital backend is configured to receive the first and second partial digital codes from the ADC segment, generate a combined digital code based at least partially on the first and second partial digital codes, determine a gain error of the ADC segment based at least partially on a first correlation of a PRBS with a difference between the first and second partial digital codes, and apply a first correction to the combined digital code based at least partially on the gain error of the ADC segment.
    Type: Application
    Filed: September 10, 2018
    Publication date: January 3, 2019
    Inventors: Viswanathan NAGARAJAN, Srinivas Kumar Reddy NARU, Narasimhan RAJAGOPAL
  • Patent number: 10103753
    Abstract: A pipeline ADC comprising an ADC segment and a digital backend coupled to the ADC segment. In some examples the ADC is configured to receive an analog signal, generate a first partial digital code representing a first sample of the analog signal, and generate a second partial digital code representing a second sample of the analog signal. In some examples the digital backend is configured to receive the first and second partial digital codes from the ADC segment, generate a combined digital code based at least partially on the first and second partial digital codes, determine a gain error of the ADC segment based at least partially on a first correlation of a PRBS with a difference between the first and second partial digital codes, and apply a first correction to the combined digital code based at least partially on the gain error of the ADC segment.
    Type: Grant
    Filed: December 8, 2017
    Date of Patent: October 16, 2018
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Viswanathan Nagarajan, Srinivas Kumar Reddy Naru, Narasimhan Rajagopal
  • Publication number: 20180191362
    Abstract: The disclosure provides an analog to digital converter (ADC). The ADC includes a flash ADC. The flash ADC generates a flash output in response to an input signal, and an error correction block generates a known pattern. A selector block is coupled to the flash ADC and the error correction block, and generates a plurality of selected signals in response to the flash output and the known pattern. A digital to analog converter (DAC) is coupled to the selector block, and generates a coarse analog signal in response to the plurality of selected signals. A residue amplifier is coupled to the DAC, and generates a residual analog signal in response to the coarse analog signal, the input signal and an analog PRBS (pseudo random binary sequence) signal. A residual ADC generates a residual code in response to the residual analog signal.
    Type: Application
    Filed: March 1, 2018
    Publication date: July 5, 2018
    Inventors: Srinivas Kumar Reddy Naru, Visvesvaraya Pentakota Appala, Shagun Dusad, Neeraj Shrivastava, Viswanathan Nagarajan, Ani Xavier, Rishi Soundararajan, Sai Aditya Nurani, Roswald Francis
  • Patent number: 9941893
    Abstract: An ADC includes a flash ADC. The flash ADC generates a flash output in response to an input signal, and an error correction block generates a known pattern. A selector block is coupled to the flash ADC and the error correction block, and generates a plurality of selected signals in response to the flash output and the known pattern. A digital to analog converter (DAC) is coupled to the selector block, and generates a coarse analog signal in response to the plurality of selected signals. A residue amplifier is coupled to the DAC, and generates a residual analog signal in response to the coarse analog signal, the input signal and an analog PRBS (pseudo random binary sequence) signal. A residual ADC generates a residual code in response to the residual analog signal.
    Type: Grant
    Filed: April 12, 2017
    Date of Patent: April 10, 2018
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Srinivas Kumar Reddy Naru, Visvesvaraya Pentakota Appala, Shagun Dusad, Neeraj Shrivastava, Viswanathan Nagarajan, Ani Xavier, Rishi Soundararajan, Sai Aditya Nurani, Roswald Francis
  • Publication number: 20170302287
    Abstract: The disclosure provides an analog to digital converter (ADC). The ADC includes a flash ADC. The flash ADC generates a flash output in response to an input signal, and an error correction block generates a known pattern. A selector block is coupled to the flash ADC and the error correction block, and generates a plurality of selected signals in response to the flash output and the known pattern. A digital to analog converter (DAC) is coupled to the selector block, and generates a coarse analog signal in response to the plurality of selected signals. A residue amplifier is coupled to the DAC, and generates a residual analog signal in response to the coarse analog signal, the input signal and an analog PRBS (pseudo random binary sequence) signal. A residual ADC generates a residual code in response to the residual analog signal.
    Type: Application
    Filed: April 12, 2017
    Publication date: October 19, 2017
    Inventors: Srinivas Kumar Reddy Naru, Visvesvaraya Pentakota Appala, Shagun Dusad, Neeraj Shrivastava, Viswanathan Nagarajan, Ani Xavier, Rishi Soundararajan, Sai Aditya Nurani, Roswald Francis