Patents by Inventor Krishna Shivaram

Krishna Shivaram 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: 11888467
    Abstract: An apparatus includes a current-based temperature compensation circuit having a reference buffer, a biasing current mirror, and a controller. The reference buffer is configured to receive a biasing reference voltage at a voltage input terminal and replicate the biasing reference voltage to first and second buffer terminals. At least one of the first and second buffer terminals is configured to be electrically connected to at least one gate terminal of an analog complementary metal oxide semiconductor (CMOS) physically unclonable function (PUF) cell. The biasing current mirror is configured to receive a reference current at a current input terminal and replicate the reference current to the first buffer terminal. The controller is configured to compensate an output of the CMOS PUF cell for temperature variation based on a weighted sum of a bandgap current, a current proportional to absolute temperature, and a current complementary to absolute temperature.
    Type: Grant
    Filed: September 17, 2021
    Date of Patent: January 30, 2024
    Assignee: Raytheon Company
    Inventor: Krishna Shivaram
  • Publication number: 20230090064
    Abstract: An apparatus includes a current-based temperature compensation circuit having a reference buffer, a biasing current mirror, and a controller. The reference buffer is configured to receive a biasing reference voltage at a voltage input terminal and replicate the biasing reference voltage to first and second buffer terminals. At least one of the first and second buffer terminals is configured to be electrically connected to at least one gate terminal of an analog complementary metal oxide semiconductor (CMOS) physically unclonable function (PUF) cell. The biasing current mirror is configured to receive a reference current at a current input terminal and replicate the reference current to the first buffer terminal. The controller is configured to compensate an output of the CMOS PUF cell for temperature variation based on a weighted sum of a bandgap current, a current proportional to absolute temperature, and a current complementary to absolute temperature.
    Type: Application
    Filed: September 17, 2021
    Publication date: March 23, 2023
    Inventor: Krishna Shivaram
  • Patent number: 9577648
    Abstract: A clock synchronization circuit has a clock sync detector. A first variable delay circuit is coupled to a first input of the clock sync detector. A controller is coupled to a digital output of the clock sync detector and a control input of the first variable delay circuit. A first clock signal is coupled to the first variable delay circuit. A second clock signal is coupled to a second input of the clock sync detector. The clock sync detector includes a first flip-flop and a first delay element coupled between the first variable delay circuit and a data input of the first flip-flop. A second variable delay circuit is coupled to a second input of the clock sync detector. A multiplexer is coupled between the first variable delay circuit and the first input of the clock sync detector. An offset compensation calibrates the clock sync detector.
    Type: Grant
    Filed: December 31, 2014
    Date of Patent: February 21, 2017
    Assignee: Semtech Corporation
    Inventors: Krishna Shivaram, Eric Vandel
  • Publication number: 20160191582
    Abstract: A method for facilitating live feed streams of remote locations by communicably connecting a first electronic streaming device to a second electronic streaming device through a back-end system. A client user account is operated on the first electronic streaming device, while a streaming account is operated on the second electronic streaming device. Tour information is submitted through the client user account, wherein a tour request is made and an event appointment is scheduled between the client user account and the streaming account. At the time of the event appointment, the client user account is communicably connected to the streaming account through the first electronic streaming device and the second electronic streaming device. A live stream video feed is then transmitted from the streaming account to the client user account, wherein the live stream video feed is viewed on the first electronic streaming device.
    Type: Application
    Filed: March 4, 2016
    Publication date: June 30, 2016
    Inventor: Krishna Shivaram
  • Publication number: 20160191062
    Abstract: A clock synchronization circuit has a clock sync detector. A first variable delay circuit is coupled to a first input of the clock sync detector. A controller is coupled to a digital output of the clock sync detector and a control input of the first variable delay circuit. A first clock signal is coupled to the first variable delay circuit. A second clock signal is coupled to a second input of the clock sync detector. The clock sync detector includes a first flip-flop and a first delay element coupled between the first variable delay circuit and a data input of the first flip-flop. A second variable delay circuit is coupled to a second input of the clock sync detector. A multiplexer is coupled between the first variable delay circuit and the first input of the clock sync detector. An offset compensation calibrates the clock sync detector.
    Type: Application
    Filed: December 31, 2014
    Publication date: June 30, 2016
    Applicant: SEMTECH CORPORATION
    Inventors: Krishna Shivaram, Eric Vandel
  • Publication number: 20150254618
    Abstract: A method for facilitating live feed streams of remote locations by communicably connecting a first electronic streaming device to a second electronic streaming device through a back-end system. A client user account is operated on the first electronic streaming device, while a streaming account is operated on the second electronic streaming device. A plurality of streaming events is displayed through the client user account, wherein a streaming selection can be made and an event appointment scheduled between the client user account and the streaming account. At the time of the event appointment, the client user account is communicably connected to the streaming account through the first electronic streaming device and the second electronic streaming device. A live stream video feed is then transmitted from the streaming account to the client user account, wherein the live stream video feed is viewed on the first electronic streaming device.
    Type: Application
    Filed: March 6, 2015
    Publication date: September 10, 2015
    Inventor: Krishna Shivaram
  • Patent number: 9030238
    Abstract: A tunable buffer circuit has a first tunable buffer cell receiving an input signal. A first transmission line is coupled to the first tunable buffer cell. A second tunable buffer cell is coupled to the first transmission line. A center frequency and bandwidth of the second tunable buffer cell is matched to a center frequency and bandwidth of the first tunable buffer cell to achieve low phase noise with low power. Additional transmission lines and tunable buffer cells can be cascaded in the tunable buffer circuit. Each tunable buffer cell has first and second transistors including first and second conduction terminals and control terminal coupled for receiving the input signal. An inductor and tunable capacitor are coupled between the first conduction terminals of the first and second transistor. A digital signal adjusts the tunable buffer cells in response to an RSSI which monitors the output for proper signal strength.
    Type: Grant
    Filed: August 26, 2013
    Date of Patent: May 12, 2015
    Assignee: Semtech Corporation
    Inventors: Krishna Shivaram, Craig Hornbuckle
  • Patent number: 9000960
    Abstract: Examples are provided for time-interleaved analog-to-digital conversion with redundancy. The redundancy may include high-order and nested redundancies. An apparatus may include multiple analog-to-digital converter (ADC) blocks coupled to one another to form a time-interleaved ADC. Each ADC block may include multiple ADC slices, wherein a count of the ADC blocks is M and some of the ADC slices may be redundant slices. A clock circuit may be configured to provide multiple clock signals. A portion N of M ADC blocks may be configured to be active, in a normal mode of operation, where N and M are integer numbers and N is smaller than M. A remaining portion of the M ADC blocks may be redundant ADC blocks, one or more of which may be selectively active, in a healing mode of operation, and be swapped for one or more failed ADC blocks using the plurality of clock signals.
    Type: Grant
    Filed: July 17, 2013
    Date of Patent: April 7, 2015
    Assignee: Semtech Corporation
    Inventors: Sandeep Louis D'Souza, Krishna Shivaram, Craig Allison Hornbuckle
  • Publication number: 20150054561
    Abstract: A tunable buffer circuit has a first tunable buffer cell receiving an input signal. A first transmission line is coupled to the first tunable buffer cell. A second tunable buffer cell is coupled to the first transmission line. A center frequency and bandwidth of the second tunable buffer cell is matched to a center frequency and bandwidth of the first tunable buffer cell to achieve low phase noise with low power. Additional transmission lines and tunable buffer cells can be cascaded in the tunable buffer circuit. Each tunable buffer cell has first and second transistors including first and second conduction terminals and control terminal coupled for receiving the input signal. An inductor and tunable capacitor are coupled between the first conduction terminals of the first and second transistor. A digital signal adjusts the tunable buffer cells in response to an RSSI which monitors the output for proper signal strength.
    Type: Application
    Filed: August 26, 2013
    Publication date: February 26, 2015
    Applicant: Semtech Corporation
    Inventors: Krishna Shivaram, Craig Hornbuckle
  • Publication number: 20150022385
    Abstract: Examples are provided for time-interleaved analog-to-digital conversion with redundancy. The redundancy may include high-order and nested redundancies. An apparatus may include multiple analog-to-digital converter (ADC) blocks coupled to one another to form a time-interleaved ADC. Each ADC block may include multiple ADC slices, wherein a count of the ADC blocks is M and some of the ADC slices may be redundant slices. A clock circuit may be configured to provide multiple clock signals. A portion N of M ADC blocks may be configured to be active, in a normal mode of operation, where N and M are integer numbers and N is smaller than M. A remaining portion of the M ADC blocks may be redundant ADC blocks, one or more of which may be selectively active, in a healing mode of operation, and be swapped for one or more failed ADC blocks using the plurality of clock signals.
    Type: Application
    Filed: July 17, 2013
    Publication date: January 22, 2015
    Inventors: Sandeep Louis D'SOUZA, Krishna Shivaram, Craig Allison Hornbuckle
  • Patent number: 8860589
    Abstract: Examples are provided for a time-interleaved analog-to-digital converter (ADC) with built-in self-healing. The ADC may include multiple ADC slices. Each ADC slice may be configured to operate in one of a normal or a healing mode of operation. In the normal mode of operation, each ADC slice may convert an input analog signal to a single digital output signal in response to a clock signal associated with the ADC slice. In the healing mode of operation, each ADC slice may be operable to convert the input analog signal to two or more digital output signals in response to two or more clock signals. One or more of the digital output signals may replace one or more output signals of failed ADC slices. A first clock signal may be associated with the ADC slice. A second clock signal may be associated with another ADC slice of the plurality of ADC slices.
    Type: Grant
    Filed: July 17, 2013
    Date of Patent: October 14, 2014
    Assignee: Semtech Corporation
    Inventors: Krishna Shivaram, Sandeep Louis D'Souza, Craig Allison Hornbuckle
  • Patent number: 8509629
    Abstract: The invention relates to amplifiers and in particular, to a transimpedance amplifier for high rate applications. Disclosed is a two stage transimpedance amplifier having a first stage comprising an amplifier and a load and a second stage comprising an amplifier and a resistor. Negative feedback is provided through a feedback resistor. Only two voltage conversions occur which reduces phase distortion, as compared to three stage transimpedance amplifiers which perform 3 voltage conversions.
    Type: Grant
    Filed: October 24, 2008
    Date of Patent: August 13, 2013
    Assignee: Mindspeed Technologies, Inc.
    Inventors: Hehong Zou, Krishna Shivaram, Daniel Draper
  • Patent number: 7973602
    Abstract: Various amplifier configurations having increased bandwidth, linearity, dynamic range, and less distortion are shown and disclosed. To increase bandwidth in a transimpedance amplifier, a replica circuit is created to replicate a degeneration resistance, or the resistance or value that relates to a feedback resistance. From the replica circuit, the replicated values are mirrored and processed to control a FET switch which modifies a degeneration resistance. The FET switch control signal is related to the feedback resistance and modifies the degeneration resistance to thereby maintain the product of the feedback resistance and the degeneration resistance as a constant. In another embodiment, a second switch controlled by an automatic gain control signal is established between a first stage amplifier and a second stage amplifier to improve dynamic range and bandwidth without degrading other amplifier specifications.
    Type: Grant
    Filed: May 6, 2009
    Date of Patent: July 5, 2011
    Assignee: Mindspeed Technologies, Inc.
    Inventors: Krishna Shivaram, Kashif A. Ahmed
  • Patent number: 7948323
    Abstract: Various amplifier configurations having increased bandwidth, linearity, dynamic range, and less distortion are shown and disclosed. To increase bandwidth in a transimpedance amplifier, a replica circuit is created to replicate a degeneration resistance, or the resistance or value that relates to a feedback resistance. From the replica circuit, the replicated values are mirrored and processed to control a FET switch which modifies a degeneration resistance. The FET switch control signal is related to the feedback resistance and modifies the degeneration resistance to thereby maintain the product of the feedback resistance and the degeneration resistance as a constant. In another embodiment, a second switch controlled by an automatic gain control signal is established between a first stage amplifier and a second stage amplifier to improve dynamic range and bandwidth without degrading other amplifier specifications.
    Type: Grant
    Filed: May 6, 2009
    Date of Patent: May 24, 2011
    Assignee: Mindspeed Technologies, Inc.
    Inventors: Krishna Shivaram, Kashif A. Ahmed
  • Publication number: 20100283543
    Abstract: Various amplifier configurations having increased bandwidth, linearity, dynamic range, and less distortion are shown and disclosed. To increase bandwidth in a transimpedance amplifier, a replica circuit is created to replicate a degeneration resistance, or the resistance or value that relates to a feedback resistance. From the replica circuit, the replicated values are mirrored and processed to control a FET switch which modifies a degeneration resistance. The FET switch control signal is related to the feedback resistance and modifies the degeneration resistance to thereby maintain the product of the feedback resistance and the degeneration resistance as a constant. In another embodiment, a second switch controlled by an automatic gain control signal is established between a first stage amplifier and a second stage amplifier to improve dynamic range and bandwidth without degrading other amplifier specifications.
    Type: Application
    Filed: May 6, 2009
    Publication date: November 11, 2010
    Inventors: Krishna Shivaram, Kashif A. Ahmed
  • Publication number: 20100283542
    Abstract: Various amplifier configurations having increased bandwidth, linearity, dynamic range, and less distortion are shown and disclosed. To increase bandwidth in a transimpedance amplifier, a replica circuit is created to replicate a degeneration resistance, or the resistance or value that relates to a feedback resistance. From the replica circuit, the replicated values are mirrored and processed to control a FET switch which modifies a degeneration resistance. The FET switch control signal is related to the feedback resistance and modifies the degeneration resistance to thereby maintain the product of the feedback resistance and the degeneration resistance as a constant. In another embodiment, a second switch controlled by an automatic gain control signal is established between a first stage amplifier and a second stage amplifier to improve dynamic range and bandwidth without degrading other amplifier specifications.
    Type: Application
    Filed: May 6, 2009
    Publication date: November 11, 2010
    Inventors: Krishna Shivaram, Kashif A. Ahmed
  • Publication number: 20090110409
    Abstract: The invention relates to amplifiers and in particular, to a transimpedance amplifier for high rate applications. Disclosed is a two stage transimpedance amplifier having a first stage comprising an amplifier and a load and a second stage comprising an amplifier and a resistor. Negative feedback is provided through a feedback resistor. Only two voltage conversions occur which reduces phase distortion, as compared to three stage transimpedance amplifiers which perform 3 voltage conversions.
    Type: Application
    Filed: October 24, 2008
    Publication date: April 30, 2009
    Inventors: Hehong Zou, Krishna Shivaram, Daniel Draper