Patents by Inventor Rajesh Cheeranthodi

Rajesh Cheeranthodi 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: 11271782
    Abstract: In some examples, a receiver can include a sampler circuit that can be configured to process a data input signal corresponding to a current bit received at a receiver based on a capacitive weighted signal to compensate for distortion effects that a previously received bit at the receiver has on the data input signal. The receiver can include a capacitive coupling feedback circuit that can be configured to generate the capacitive weighted signal corresponding to a weighted detected bit of the previously received bit based on a capacitance of a subset of capacitors of a plurality of capacitors of the feedback circuit. The capacitive coupling feedback circuit can be configured to selectively control a number of capacitors of the plurality of capacitors that are connected in parallel corresponding to the subset of capacitors to control an amount of weight applied to the detected bit to generate the capacitive weighted signal.
    Type: Grant
    Filed: September 4, 2020
    Date of Patent: March 8, 2022
    Assignee: CADENCE DESIGN SYSTEMS, INC.
    Inventors: Vineeth Anavangot, Maitri Misra, Rajesh Cheeranthodi
  • Patent number: 9698968
    Abstract: System, method and computer program product for setting phase control codes to (in-phase) I and (quadrature) Q rotators to a first code pair, different by enough to produce a phase difference between the rotator outputs sufficient to be detected with minimal error by a phase-to-voltage converter. Auxiliary trim DACs are then adjusted according to calibration logic until a comparator output detects a phase difference between the I and Q rotators are within tolerable limits. The resulting trim codes are stored for both the codes in the pair. These trim codes along with the main codes are subsequently applied whenever the codes are used thereafter. These steps are repeated with each successive code pair having the same separation as the first code pair, e.g. both incremented by same amount until all codes have been calibrated. In this manner having the phase separation between all code pairs forced to the same value.
    Type: Grant
    Filed: March 2, 2016
    Date of Patent: July 4, 2017
    Assignee: International Business Machines Corporation
    Inventors: Anthony R. Bonaccio, Timothy C. Buchholtz, Rajesh Cheeranthodi, Giri N. Rangan, Sergey V. Rylov
  • Publication number: 20160182216
    Abstract: System, method and computer program product for setting phase control codes to (in-phase) I and (quadrature) Q rotators to a first code pair, different by enough to produce a phase difference between the rotator outputs sufficient to be detected with minimal error by a phase-to-voltage converter. Auxiliary trim DACs are then adjusted according to calibration logic until a comparator output detects a phase difference between the I and Q rotators are within tolerable limits. The resulting trim codes are stored for both the codes in the pair. These trim codes along with the main codes are subsequently applied whenever the codes are used thereafter. These steps are repeated with each successive code pair having the same separation as the first code pair, e.g. both incremented by same amount until all codes have been calibrated. In this manner having the phase separation between all code pairs forced to the same value.
    Type: Application
    Filed: March 2, 2016
    Publication date: June 23, 2016
    Inventors: Anthony R. Bonaccio, Timothy C. Buchholtz, Rajesh Cheeranthodi, Giri N. Rangan, Sergey V. Rylov
  • Patent number: 9306729
    Abstract: System, method and computer program product for setting phase control codes to (in-phase) I and (quadrature) Q rotators to a first code pair, different by enough to produce a phase difference between the rotator outputs sufficient to be detected with minimal error by a phase-to-voltage converter. Auxiliary trim DACs are then adjusted according to calibration logic until a comparator output detects a phase difference between the I and Q rotators are within tolerable limits. The resulting trim codes are stored for both the codes in the pair. These trim codes along with the main codes are subsequently applied whenever the codes are used thereafter. These steps are repeated with each successive code pair having the same separation as the first code pair, e.g. both incremented by same amount until all codes have been calibrated. In this manner having the phase separation between all code pairs forced to the same value.
    Type: Grant
    Filed: January 14, 2014
    Date of Patent: April 5, 2016
    Assignee: International Business Machines Corporation
    Inventors: Anthony R. Bonaccio, Timothy C. Buchholtz, Rajesh Cheeranthodi, Giri N. Rangan, Sergey V. Rylov
  • Publication number: 20150200765
    Abstract: System, method and computer program product for setting phase control codes to (in-phase) I and (quadrature) Q rotators to a first code pair, different by enough to produce a phase difference between the rotator outputs sufficient to be detected with minimal error by a phase-to-voltage converter. Auxiliary trim DACs are then adjusted according to calibration logic until a comparator output detects a phase difference between the I and Q rotators are within tolerable limits. The resulting trim codes are stored for both the codes in the pair. These trim codes along with the main codes are subsequently applied whenever the codes are used thereafter. These steps are repeated with each successive code pair having the same separation as the first code pair, e.g. both incremented by same amount until all codes have been calibrated. In this manner having the phase separation between all code pairs forced to the same value.
    Type: Application
    Filed: January 14, 2014
    Publication date: July 16, 2015
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Anthony R. Bonaccio, Timothy C. Buchholtz, Rajesh Cheeranthodi, Giri N. Rangan, Sergey V. Rylov
  • Patent number: 8872587
    Abstract: Apparatuses for generating negative impedance compensation are provided. Embodiments include a differential amplifier having a first output and a second output; a capacitor coupled between the first output and the second output of the differential amplifier; a first negative impedance cross-coupled circuit having a first output and a second output; and a resistance control circuit coupled in series between the first output and the second output of the differential amplifier and the first output and the second output of the first negative impedance cross-coupled circuit.
    Type: Grant
    Filed: March 6, 2013
    Date of Patent: October 28, 2014
    Assignee: International Business Machines Corporation
    Inventors: Rajesh Cheeranthodi, John F. Ewen, Santhosh Madhavan, Giri N. K. Rangan, Umesh K. Shukla, Sarabjeet Singh
  • Publication number: 20140253236
    Abstract: Apparatuses for generating negative impedance compensation are provided. Embodiments include a differential amplifier having a first output and a second output; a capacitor coupled between the first output and the second output of the differential amplifier; a first negative impedance cross-coupled circuit having a first output and a second output; and a resistance control circuit coupled in series between the first output and the second output of the differential amplifier and the first output and the second output of the first negative impedance cross-coupled circuit.
    Type: Application
    Filed: March 6, 2013
    Publication date: September 11, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: RAJESH CHEERANTHODI, JOHN F. EWEN, SANTHOSH MADHAVAN, GIRI N.K. RANGAN, UMESH K. SHUKLA, SARABJEET SINGH
  • Patent number: 8415985
    Abstract: Circuits and methods for sampling differential input signals having wide input swings including voltages below ground potential, and capable of operating on a single positive supply voltage are disclosed. In an embodiment, the circuit includes a first input switch circuit and a second input switch circuit, a sample and hold circuitry and an operational amplifier. Each of the first and second input switch circuits includes serially connected PMOS switch and NMOS switch for receiving a differential input signal. The sample and hold circuitry includes a first sampling capacitor, a second sampling capacitor and a plurality of switches. The switches are configured to provide the differential input signal to the sampling capacitors for the sampling in a sample phase, and are configured to provide the sampled differential input signal at an output of the operational amplifier in a hold phase.
    Type: Grant
    Filed: July 11, 2011
    Date of Patent: April 9, 2013
    Assignee: Texas Instruments Incorporated
    Inventor: Rajesh Cheeranthodi
  • Publication number: 20130015991
    Abstract: Circuits and methods for sampling differential input signals having wide input swings including voltages below ground potential, and capable of operating on a single positive supply voltage are disclosed. In an embodiment, the circuit includes a first input switch circuit and a second input switch circuit, a sample and hold circuitry and an operational amplifier. Each of the first and second input switch circuits includes serially connected PMOS switch and NMOS switch for receiving a differential input signal. The sample and hold circuitry includes a first sampling capacitor, a second sampling capacitor and a plurality of switches. The switches are configured to provide the differential input signal to the sampling capacitors for the sampling in a sample phase, and are configured to provide the sampled differential input signal at an output of the operational amplifier in a hold phase.
    Type: Application
    Filed: July 11, 2011
    Publication date: January 17, 2013
    Applicant: Texas Instruments Incorporated
    Inventor: Rajesh Cheeranthodi