Patents by Inventor David Cassan

David Cassan 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: 8879618
    Abstract: A decision feedback equalizer, transceiver, and method are provided, the equalizer having at least one comparator, the at least one comparator comprising a first stage, comprising a main branch having two track switches with a resistive load, an offset cancellation branch, a plurality of tap branches with transistor sizes smaller than the main branch, in which previous decisions of the equalizer are mixed with the tap weights using current-mode switching, and a cross coupled latch branch; and a second stage, comprising a comparator module for making decisions based on the outputs of the first stage and a clock input, and a plurality of flip-flops for storing the output of the comparator module.
    Type: Grant
    Filed: September 13, 2011
    Date of Patent: November 4, 2014
    Assignee: Semtech Canada Corporation
    Inventors: Mohamed Abdalla, Afshin Rezayee, David Cassan, Marcus Van Ierssel, Chris Holdenried, Saman Sadr
  • Patent number: 8878568
    Abstract: A high speed transmit driver is provided, along with methods to improve driver slew rate, decrease transmit jitter, improve termination accuracy, and decrease sensitivity to supply noise.
    Type: Grant
    Filed: October 24, 2012
    Date of Patent: November 4, 2014
    Assignee: Semtech Corporation
    Inventors: Kamran Farzan, Mehrdad Ramezani, David Cassan, Angus McLaren, Saman Sadr
  • Publication number: 20120201289
    Abstract: A decision feedback equalizer, transceiver, and method are provided, the equalizer having at least one comparator, the at least one comparator comprising a first stage, comprising a main branch having two track switches with a resistive load, an offset cancellation branch, a plurality of tap branches with transistor sizes smaller than the main branch, in which previous decisions of the equalizer are mixed with the tap weights using current-mode switching, and a cross coupled latch branch; and a second stage, comprising a comparator module for making decisions based on the outputs of the first stage and a clock input, and a plurality of flip-flops for storing the output of the comparator module.
    Type: Application
    Filed: September 13, 2011
    Publication date: August 9, 2012
    Inventors: Mohamed ABDALLA, Afshin REZAYEE, David CASSAN, Marcus VAN IERSSEL, Chris HOLDENRIED, Saman SADR
  • Publication number: 20060164132
    Abstract: A fractional-N frequency synthesizer is described that includes a voltage controlled oscillator (VCO), a programmable integer divider, and a glitch-free phase rotator. The phase select inputs of the phase rotator are controlled by a delta-sigma modulator to provide fine frequency resolution in addition to randomization and noise shaping of fractional quantization noise. The delta-sigma modulator is clocked at rates higher than the synthesizer reference clock resulting in an improvement in clock jitter at the output of the frequency synthesizer. A glitch-free phase multiplexer design is used to implement the phase rotator fractional divider to enables operation at rates higher than the reference clock. The over-sampling ratio of the delta-sigma modulator over the reference clock frequency of the PLL translates directly into an improvement in the quality of the output clock with respect to fractional quantization noise, phase mismatch, and digital noise injection.
    Type: Application
    Filed: September 30, 2005
    Publication date: July 27, 2006
    Applicant: Snowbush Inc.
    Inventors: Kenneth Martin, David Cassan