Patents by Inventor Darren Walker

Darren Walker 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: 12615053
    Abstract: In one embodiment, the disclosure relates to a current steering DAC system. The system may include a current steering digital to analogy converter (DAC) that includes a clock buffer configured to generate a first clock signal having a first frequency and a second clock signal having a second frequency; a tail node; a first clock switch in electrical communication with the tail node; a second clock switch in electrical communication with the tail node; and a current source comprising an inductor having an inductance, the current source in electrical communication with the tail node.
    Type: Grant
    Filed: March 20, 2024
    Date of Patent: April 28, 2026
    Assignee: Cisco Technology, Inc.
    Inventors: Ian Dedic, Darren Walker
  • Patent number: 12470203
    Abstract: In one embodiment, the disclosure relates to a phase detector. The phase detector may include a first inductor having an inductance L1; a second inductor having an inductance L2; and a frequency mixer having a parasitic capacitance CTail, the frequency mixer comprising, a common node tail; a first clock signal generator configured to output a first clock signal having a first frequency, a second clock signal generator configured to output a second clock signal having a second frequency, the first clock signal generator and the second clock signal generator in electrical communication with the common node tail, a first resistor in electrical communication with the first clock signal generator, a second resistor in electrical communication with the second clock signal generator, and an output channel configured to transmit a DC voltage signal (Vphase) that corresponds to the phase relationship between the first clock signal and the second clock signal.
    Type: Grant
    Filed: March 20, 2024
    Date of Patent: November 11, 2025
    Assignee: Cisco Technology, Inc.
    Inventors: Ian Dedic, Darren Walker, Vineet Mishra
  • Patent number: 12232264
    Abstract: In an embodiment, an apparatus and system comprising a first inductor with a first diameter; and a switched inductor including a metal layer and a switch; wherein when the switch is closed the switch connects the metal layer of the switched inductor to form an inductor with a parallel circuit enabling current to flow through the switched conductor; and wherein when the switch is open, current is not enabled to flow through the switched conductor. In another embodiment, a method for tuning a high-Q inductor, the method comprising closing a switch of a switched inductor, wherein the switch connects the switched inductor to a first inductor; wherein closing the switch enables current to flow though the switched inductor as well as the first inductor to change the inductance of the high Q inductor.
    Type: Grant
    Filed: September 9, 2019
    Date of Patent: February 18, 2025
    Assignee: ACACIA COMMUNICATIONS, INC.
    Inventors: Ian Dedic, David Enright, Darren Walker, Tarun Gupta
  • Patent number: 10530342
    Abstract: Clock distribution circuitry configured for duty cycle control, the circuitry comprising: a plurality of buffers connected in series along a clock path, each of the buffers having an input terminal and an output terminal, the input terminal being connected to the clock path via a corresponding AC coupling capacitor, and the clock, path configured to receive an input clock signal at its input node and output an output clock signal at its output node, the output clock signal having an output duty cycle; and control circuitry connected to apply a DC bias signal to the input terminal of each of the plurality of buffers, wherein the control circuitry is configured to: obtain a measurement signal indicative of the output duty cycle; and control the DC bias signals, based on a difference between the measurement signal and a reference signal, so as to control the output duty cycle.
    Type: Grant
    Filed: January 9, 2019
    Date of Patent: January 7, 2020
    Assignee: SOCIONEXT INC.
    Inventors: Sylvain Panier, Behzad Farzaneh, Darren Walker, Ian Juso Dedic
  • Publication number: 20190229711
    Abstract: Clock distribution circuitry configured for duty cycle control, the circuitry comprising: a plurality of buffers connected in series along a clock path, each of the buffers having an input terminal and an output terminal, the input terminal being connected to the clock path via a corresponding AC coupling capacitor, and the clock, path configured to receive an input clock signal at its input node and output an output clock signal at its output node, the output clock signal having an output duty cycle; and control circuitry connected to apply a DC bias signal to the input terminal of each of the plurality of buffers, wherein the control circuitry is configured to: obtain a measurement signal indicative of the output duty cycle; and control the DC bias signals, based on a difference between the measurement signal and a reference signal, so as to control the output duty cycle.
    Type: Application
    Filed: January 9, 2019
    Publication date: July 25, 2019
    Inventors: Sylvain PANIER, Behzad Farzaneh, Darren Walker, Ian Juso Dedic
  • Patent number: 10135600
    Abstract: There is disclosed herein multiplexer circuitry. In particular, there is disclosed a latch circuit for use as a multiplexer to multiplex information carried by respective pairs of input information signals onto an output information signal, each pair of input information signals comprising a first input information signal and a second input information signal, and each pair of input information signals carrying information values based on signal values of those input information signals and interleaved with information values carried by the other pair or pairs of input information signals.
    Type: Grant
    Filed: March 10, 2017
    Date of Patent: November 20, 2018
    Assignee: SOCIONEXT INC.
    Inventors: Darren Walker, Ian Juso Dedic
  • Publication number: 20170264421
    Abstract: There is disclosed herein multiplexer circuitry. In particular, there is disclosed a latch circuit for use as a multiplexer to multiplex information carried by respective pairs of input information signals onto an output information signal, each pair of input information signals comprising a first input information signal and a second input information signal, and each pair of input information signals carrying information values based on signal values of those input information signals and interleaved with information values carried by the other pair or pairs of input information signals.
    Type: Application
    Filed: March 10, 2017
    Publication date: September 14, 2017
    Inventors: Darren WALKER, Ian Juso Dedic
  • Patent number: 7746259
    Abstract: A digital-to-analog converter, comprising: a first field-effect transistor; a second field-effect transistor; and adjusting means for adjusting a bulk voltage applied to at least one of the first and second field-effect transistors so as to tend to equalise respective switching delays of the transistors.
    Type: Grant
    Filed: July 24, 2008
    Date of Patent: June 29, 2010
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Ian Juso Dedic, Darren Walker
  • Publication number: 20090051576
    Abstract: A digital-to-analog converter, comprising: a first field-effect transistor; a second field-effect transistor; and adjusting means for adjusting a bulk voltage applied to at least one of the first and second field-effect transistors so as to tend to equalise respective switching delays of the transistors.
    Type: Application
    Filed: July 24, 2008
    Publication date: February 26, 2009
    Applicant: Fujitsu Limited
    Inventors: Ian Juso Dedic, Darren Walker
  • Patent number: 7034733
    Abstract: Segmented mixed signal circuitry comprising a plurality of analog segments is disclosed. Each analog segment is operable to perform a series of switching operations dependent on an input data signal. The circuitry is arranged to receive shaped clock signals provided in common for all segments, and to perform each switching operation in a manner determined by the shape of the common shaped clock signals. The circuitry is suitable for use in digital to analog converters (DACs).
    Type: Grant
    Filed: June 3, 2002
    Date of Patent: April 25, 2006
    Assignee: Fujitsu Limited
    Inventors: Ian Juso Dedic, Darren Walker
  • Publication number: 20030043062
    Abstract: Segmented mixed signal circuitry comprising a plurality of analog segments is disclosed. Each analog segment is operable to perform a series of switching operations dependent on an input data signal. The circuitry is arranged to receive shaped clock signals provided in common for all segments, and to perform each switching operation in a manner determined by the shape of the common shaped clock signals. The circuitry is suitable for use in digital to analog converters (DACs).
    Type: Application
    Filed: June 3, 2002
    Publication date: March 6, 2003
    Applicant: FUJITSU LIMITED
    Inventors: Ian Juso Dedic, Darren Walker