Patents by Inventor Rajasekhar Nagulapalli

Rajasekhar Nagulapalli 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: 11757355
    Abstract: The present invention is directed to electrical circuits. According to an embodiment, the present invention provides a charge pump circuit with a bias section and a switch section. The switch section includes a first switch coupled to an early signal and a second switch coupled to a late signal. The charge pump additionally includes a low-pass filter. The switch section includes a first resistor and a second resistor. The first resistor is directly coupled to the first switch and the low-pass filter. The second resistor is directly coupled to the second switch and the first resistor. There are other embodiments as well.
    Type: Grant
    Filed: December 1, 2021
    Date of Patent: September 12, 2023
    Assignee: Marvell Asia Pte, Ltd.
    Inventors: Rajasekhar Nagulapalli, Simon Forey, Parmanand Mishra
  • Publication number: 20200403503
    Abstract: The present invention is directed to electrical circuits. According to an embodiment, the present invention provides a charge pump circuit with a bias section and a switch section. The switch section includes a first switch coupled to an early signal and a second switch coupled to a late signal. The charge pump additionally includes a low-pass filter. The switch section includes a first resistor and a second resistor. The first resistor is directly coupled to the first switch and the low-pass filter. The second resistor is directly coupled to the second switch and the first resistor. There are other embodiments as well.
    Type: Application
    Filed: September 8, 2020
    Publication date: December 24, 2020
    Inventors: Rajasekhar NAGULAPALLI, Simon FOREY, Parmanand MISHRA
  • Patent number: 10804797
    Abstract: The present invention is directed to electrical circuits. According to an embodiment, the present invention provides a charge pump circuit with a bias section and a switch section. The switch section includes a first switch coupled to an early signal and a second switch coupled to a late signal. The charge pump additionally includes a low-pass filter. The switch section includes a first resistor and a second resistor. The first resistor is directly coupled to the first switch and the low-pass filter. The second resistor is directly coupled to the second switch and the first resistor. There are other embodiments as well.
    Type: Grant
    Filed: February 25, 2019
    Date of Patent: October 13, 2020
    Assignee: INPHI CORPORATION
    Inventors: Rajasekhar Nagulapalli, Simon Forey, Parmanand Mishra
  • Patent number: 10771065
    Abstract: The present invention is directed to electrical circuits. More specifically, embodiments of the present invention provide a charge pump, which can be utilized as a part of a clock data recovery device. Early and late signals are used as differential switching voltage signals in the charge pump. The first switch and a second switch are used for controlling the direction of the current flowing into the loop filter. Input differential voltages to the switches are being generated with an opamp negative feedback loop. The output voltage of the first switch and the second switch is used in conjunction with a resistor to generate a charge pump current. There are other embodiments as well.
    Type: Grant
    Filed: October 25, 2019
    Date of Patent: September 8, 2020
    Assignee: INPHI CORPORATION
    Inventors: Simon Forey, Parmanand Mishra, Michael S. Harwood, Rajasekhar Nagulapalli
  • Patent number: 10763810
    Abstract: The present invention is directed to electrical circuits and techniques thereof. In various embodiments, the present invention provides a variable gain amplifier architecture that includes a continuous-time linear equalizer (CTLE) section and a variable gain amplifier (VGA) section. The CTLE section provides both a pair of equalized data signals and a common mode voltage. A DAC generates a control signal based on a control code. The VGA section amplifies the pair of equalized data signals by an amplification factor using a transistor whose resistance value is based on both the common mode voltage and the control signal. There are other embodiments as well.
    Type: Grant
    Filed: March 5, 2020
    Date of Patent: September 1, 2020
    Assignee: INPHI CORPORATION
    Inventors: Simon Forey, Rajasekhar Nagulapalli, Parmanand Mishra
  • Patent number: 10764092
    Abstract: The present invention is directed to communication systems and electrical circuits. According to an embodiment, an input termination circuit includes a first attenuation resistor and a second attenuation resistor. The resistance values of these two resistors are adjusted in opposite directions to maintain a stable output impedance. There are other embodiments as well.
    Type: Grant
    Filed: November 12, 2019
    Date of Patent: September 1, 2020
    Assignee: INPHI CORPORATION
    Inventors: Simon Forey, Rajasekhar Nagulapalli, Parmanand Mishra
  • Publication number: 20200204131
    Abstract: The present invention is directed to electrical circuits and techniques thereof. In various embodiments, the present invention provides a variable gain amplifier architecture that includes a continuous-time linear equalizer (CTLE) section and a variable gain amplifier (VGA) section. The CTLE section provides both a pair of equalized data signals and a common mode Voltage. A DAC generates a control signal based on a control code. The VGA section amplifies the pair of equalized data signals by an amplification factor using a transistor whose resistance value is based on both the common mode voltage and the control signal. There are other embodiments as well.
    Type: Application
    Filed: March 5, 2020
    Publication date: June 25, 2020
    Inventors: Simon FOREY, Rajasekhar NAGULAPALLI, Parmanand MISHRA
  • Patent number: 10622955
    Abstract: The present invention is directed to electrical circuits and techniques thereof. In various embodiments, the present invention provides a variable gain amplifier architecture that includes a continuous-time linear equalizer (CTLE) section and a variable gain amplifier (VGA) section. The CTLE section provides both a pair of equalized data signals and a common mode voltage. A DAC generates a control signal based on a control code. The VGA section amplifies the pair of equalized data signals by an amplification factor using a transistor whose resistance value is based on both the common mode voltage and the control signal. There are other embodiments as well.
    Type: Grant
    Filed: March 6, 2019
    Date of Patent: April 14, 2020
    Assignee: INPHI CORPORATION
    Inventors: Simon Forey, Rajasekhar Nagulapalli, Parmanand Mishra
  • Publication number: 20200084067
    Abstract: The present invention is directed to communication systems and electrical circuits. According to an embodiment, an input termination circuit includes a first attenuation resistor and a second attenuation resistor. The resistance values of these two resistors are adjusted in opposite directions to maintain a stable output impedance. There are other embodiments as well.
    Type: Application
    Filed: November 12, 2019
    Publication date: March 12, 2020
    Inventors: Simon FOREY, Rajasekhar NAGULAPALLI, Parmanand MISHRA
  • Publication number: 20200059348
    Abstract: The present invention is directed to electrical circuits. More specifically, embodiments of the present invention provide a charge pump, which can be utilized as a part of a clock data recovery device. Early and late signals are used as differential switching voltage signals in the charge pump. The first switch and a second switch are used for controlling the direction of the current flowing into the loop filter. Input differential voltages to the switches are being generated with an opamp negative feedback loop. The output voltage of the first switch and the second switch is used in conjunction with a resistor to generate a charge pump current. There are other embodiments as well.
    Type: Application
    Filed: October 25, 2019
    Publication date: February 20, 2020
    Inventors: Simon FOREY, Parmanand MISHRA, Michael S. HARWOOD, Rajasekhar NAGULAPALLI
  • Patent number: 10505766
    Abstract: The present invention is directed to communication systems and electrical circuits. According to an embodiment, an input termination circuit includes a first attenuation resistor and a second attenuation resistor. The resistance values of these two resistors are adjusted in opposite directions to maintain a stable output impedance. There are other embodiments as well.
    Type: Grant
    Filed: March 20, 2019
    Date of Patent: December 10, 2019
    Assignee: INPHI CORPORATION
    Inventors: Simon Forey, Rajasekhar Nagulapalli, Parmanand Mishra
  • Patent number: 10498526
    Abstract: The present invention is directed to electrical circuits. More specifically, embodiments of the present invention provide a charge pump, which can be utilized as a part of a clock data recovery device. Early and late signals are used as differential switching voltage signals in the charge pump. The first switch and a second switch are used for controlling the direction of the current flowing into the loop filter. Input differential voltages to the switches are being generated with an opamp negative feedback loop. The output voltage of the first switch and the second switch is used in conjunction with a resistor to generate a charge pump current. There are other embodiments as well.
    Type: Grant
    Filed: February 8, 2019
    Date of Patent: December 3, 2019
    Assignee: INPHI CORPORATION
    Inventors: Simon Forey, Parmanand Mishra, Michael S. Harwood, Rajasekhar Nagulapalli
  • Publication number: 20190207576
    Abstract: The present invention is directed to electrical circuits and techniques thereof. In various embodiments, the present invention provides a variable gain amplifier architecture that includes a continuous-time linear equalizer (CTLE) section and a variable gain amplifier (VGA) section. The CTLE section provides both a pair of equalized data signals and a common mode voltage. A DAC generates a control signal based on a control code. The VGA section amplifies the pair of equalized data signals by an amplification factor using a transistor whose resistance value is based on both the common mode voltage and the control signal. There are other embodiments as well.
    Type: Application
    Filed: March 6, 2019
    Publication date: July 4, 2019
    Inventors: Simon FOREY, Rajasekhar NAGULAPALLI, Parmanand MISHRA
  • Patent number: 10333527
    Abstract: Embodiments of the present invention provide techniques for duty cycle correction of clock signals. An input clock signal passes through a pair of output transistors, which provides an output clock signal based on the input clock signal. A duty cycle sensor generates a first correction signal based on the output clock signal. The first correction signal is at least partially opposite of the output clock signal. A duty cycle corrector generates a second correction signal based on the first correction signal. The duty cycle corrector includes two or more transistors for generating the second correction signal. The second correction signal is applied to the output clock signal. There are other embodiments as well.
    Type: Grant
    Filed: October 8, 2018
    Date of Patent: June 25, 2019
    Assignee: INPHI CORPORATION
    Inventors: Simon Forey, Rajasekhar Nagulapalli, Parmanand Mishra
  • Patent number: 10284394
    Abstract: The present invention is directed to communication systems and electrical circuits. According to an embodiment, an input termination circuit includes a first attenuation resistor and a second attenuation resistor. The resistance values of these two resistors are adjusted in opposite directions to maintain a stable output impedance. There are other embodiments as well.
    Type: Grant
    Filed: August 10, 2018
    Date of Patent: May 7, 2019
    Assignee: INPHI CORPORATION
    Inventors: Simon Forey, Rajasekhar Nagulapalli, Parmanand Mishra
  • Patent number: 10270409
    Abstract: The present invention is directed to electrical circuits and techniques thereof. In various embodiments, the present invention provides a variable gain amplifier architecture that includes a continuous-time linear equalizer (CTLE) section and a variable gain amplifier (VGA) section. The CTLE section provides both a pair of equalized data signals and a common mode voltage. A DAC generates a control signal based on a control code. The VGA section amplifies the pair of equalized data signals by an amplification factor using a transistor whose resistance value is based on both the common mode voltage and the control signal. There are other embodiments as well.
    Type: Grant
    Filed: May 16, 2017
    Date of Patent: April 23, 2019
    Assignee: INPHI CORPORATION
    Inventors: Simon Forey, Rajasekhar Nagulapalli, Parmanand Mishra
  • Patent number: 10243570
    Abstract: The present invention is directed to electrical circuits. More specifically, embodiments of the present invention provide a charge pump, which can be utilized as a part of a clock data recovery device. Early and late signals are used as differential switching voltage signals in the charge pump. The first switch and a second switch are used for controlling the direction of the current flowing into the loop filter. Input differential voltages to the switches are being generated with an opamp negative feedback loop. The output voltage of the first switch and the second switch is used in conjunction with a resistor to generate a charge pump current. There are other embodiments as well.
    Type: Grant
    Filed: July 28, 2017
    Date of Patent: March 26, 2019
    Assignee: INPHI CORPORATION
    Inventors: Simon Forey, Parmanand Mishra, Michael Harwood, Rajasekhar Nagulapalli
  • Publication number: 20190044521
    Abstract: Embodiments of the present invention provide techniques for duty cycle correction of clock signals. An input clock signal passes through a pair of output transistors, which provides an output clock signal based on the input clock signal. A duty cycle sensor generates a first correction signal based on the output clock signal. The first correction signal is at least partially opposite of the output clock signal. A duty cycle corrector generates a second correction signal based on the first correction signal. The duty cycle corrector includes two or more transistors for generating the second correction signal. The second correction signal is applied to the output clock signal. There are other embodiments as well.
    Type: Application
    Filed: October 8, 2018
    Publication date: February 7, 2019
    Inventors: Simon FOREY, Rajasekhar NAGULAPALLI, Parmanand MISHRA
  • Patent number: 10193640
    Abstract: The present invention is directed to data communication. According to a specific embodiment, the present invention provides technique for loss of signal detection. A loss-of-signal detection (LOSD) device determines an analog signal indicating signal strength by subtracting a threshold offset voltage from an incoming signal. The analog signal is then processed by a switch network of an output stage circuit, which provides a digital output of loss of signal indication at a low frequency (relative to the incoming signal frequency). There are other embodiments as well.
    Type: Grant
    Filed: May 31, 2018
    Date of Patent: January 29, 2019
    Assignee: INPHI CORPORATION
    Inventors: Simon Forey, Rajasekhar Nagulapalli, Parmanand Mishra, Michael S. Harwood
  • Patent number: 10193515
    Abstract: The present invention is directed to electrical circuits. More specifically, embodiments of the presentation provide a CTLE module that includes a two compensation sections. A high-frequency zero RC section is in the source of the differential pair and close to the bias current source. A low-frequency zero section is coupled to an output terminal and configured outside the input signal path. A DC gain tuning section is coupled to the low-frequency zero section. There are other embodiments as well.
    Type: Grant
    Filed: August 10, 2018
    Date of Patent: January 29, 2019
    Assignee: INPHI CORPORATION
    Inventors: Rajasekhar Nagulapalli, Simon Forey, Parmanand Mishra