Patents by Inventor Boris Drakhlis

Boris Drakhlis 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).

  • Crystal clock generator operating at third overtone of crystal's fundamental frequency
    Patent number: 7332977
    Abstract: A crystal oscillator operates at the third overtone of the crystal's fundamental frequency. A value of a shunt resistor between the two phase-shift leg nodes is chosen so that the absolute value of the product gm×(Xc1)×(Xc2) is greater than the effective reactance of the crystal, where gm is the gain of the amplifier attached to the phase-shift legs, and Xc1 and Xc2 are the effective capacitive reactances of phase-shift legs at nodes X1 and X2. The third overtone is doubled by a multiplier and the final output filtered to remove the third overtone and select a frequency six times the fundamental frequency. A pair of Colpitts or Pierce amplifier half circuits is attached to the phase-shift leg nodes. The leg nodes can be capacitively isolated from Pierce-amplifier circuit nodes to improve start-up. Frequency doubling can be performed by summing currents from the two oscillator half circuits.
    Type: Grant
    Filed: December 21, 2005
    Date of Patent: February 19, 2008
    Assignee: Pericom Semiconductor Corp.
    Inventors: Boris Drakhlis, Wing Faat Liu, Craig M. Taylor, Tony Yeung
  • Crystal Clock Generator Operating at Third Overtone of Crystal's Fundamental Frequency
    Publication number: 20070069826
    Abstract: A crystal oscillator operates at the third overtone of the crystal's fundamental frequency. A value of a shunt resistor between the two phase-shift leg nodes is chosen so that the absolute value of the product gm×(Xc1)×(Xc2) is greater than the effective reactance of the crystal, where gm is the gain of the amplifier attached to the phase-shift legs, and Xc1 and Xc2 are the effective capacitive reactances of phase-shift legs at nodes X1 and X2. The third overtone is doubled by a multiplier and the final output filtered to remove the third overtone and select a frequency six times the fundamental frequency. A pair of Colpitts or Pierce amplifier half circuits is attached to the phase-shift leg nodes. The leg nodes can be capacitively isolated from Pierce-amplifier circuit nodes to improve start-up. Frequency doubling can be performed by summing currents from the two oscillator half circuits.
    Type: Application
    Filed: December 21, 2005
    Publication date: March 29, 2007
    Applicant: PERICOM SEMICONDUCTOR CORP.
    Inventors: Boris Drakhlis, Wing Faat Liu, Craig Taylor, Tony Yeung
  • Crystal clock generator operating at third overtone of crystal's fundamental frequency
    Patent number: 7002423
    Abstract: A crystal oscillator operates at the third overtone of the crystal's fundamental frequency. A value of a shunt resistor between the two phase-shift leg nodes is chosen so that the absolute value of the product gm×(Xc1)×(Xc2) is greater than the effective reactance of the crystal, where gm is the gain of the amplifier attached to the phase-shift legs, and Xc1 and Xc2 are the effective capacitive reactances of phase-shift legs at nodes X1 and X2. The third overtone is doubled by a multiplier and the final output filtered to remove the third overtone and select a frequency six times the fundamental frequency. A pair of Colpitts or Pierce amplifier half circuits is attached to the phase-shift leg nodes. The leg nodes can be capacitively isolated from Pierce-amplifier circuit nodes to improve start-up. Frequency doubling can be performed by summing currents from the two oscillator half circuits.
    Type: Grant
    Filed: July 20, 2004
    Date of Patent: February 21, 2006
    Assignee: Pericom Semiconductor Corp.
    Inventors: Boris Drakhlis, Wing Faat Liu, Craig M. Taylor, Tony Yeung