Patents by Inventor Stefanos Stefanidis

Stefanos Stefanidis 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).

  • Publication number: 20190229678
    Abstract: A crystal oscillator circuit comprises a crystal; oscillator circuitry for generating a crystal oscillation signal at an oscillation frequency; and a kick-start circuit for injecting pulses into the crystal during a start-up period. The oscillator circuitry comprises a differential pair of transistors and can operate in an oscillating mode or a start-up mode. In the oscillating mode, the differential pair of transistors is cross-coupled so that a gate terminal of one transistor is coupled to a drain terminal of the other transistor, and vice versa, and the drain terminals are coupled to the crystal to generate the crystal oscillation signal. In the start-up mode, the kick-start circuit drives the gate terminals of the transistors with said pulses. This crystal oscillator circuit has a decreased start-up time compared to prior art solutions and a reduced influence of parasitic oscillations.
    Type: Application
    Filed: April 4, 2019
    Publication date: July 25, 2019
    Inventors: Anna Karin Stenman, Stefanos Stefanidis, Lars Sundström, Tahmineh Torabian Esfahani
  • Patent number: 10312860
    Abstract: A crystal oscillator circuit comprises a crystal; oscillator circuitry for generating a crystal oscillation signal at an oscillation frequency; and a kick-start circuit for injecting pulses into the crystal during a start-up period. The oscillator circuitry comprises a differential pair of transistors and can operate in an oscillating mode or a start-up mode. In the oscillating mode, the differential pair of transistors are cross-coupled so that a gate terminal of one transistor is coupled to a drain terminal of the other transistor, and vice versa, and the drain terminals are coupled to the crystal to generate the crystal oscillation signal. In the start-up mode, the kick-start circuit drives the gate terminals of the transistors with said pulses. This crystal oscillator circuit has a decreased start-up time compared to prior art solutions and a reduced influence of parasitic oscillations.
    Type: Grant
    Filed: March 13, 2015
    Date of Patent: June 4, 2019
    Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
    Inventors: Anna Karin Stenman, Stefanos Stefanidis, Lars Sundström, Tahmineh Torabian Esfahani
  • Publication number: 20180198411
    Abstract: A crystal oscillator circuit comprises a crystal (X1); oscillator circuitry (31) for generating a crystal oscillation signal at an oscillation frequency; and a kick-start circuit (12) for injecting pulses into the crystal during a start-up period. The oscillator circuitry (31) comprises a differential pair of transistors (M1, M2) and can operate in an oscillating mode or a start-up mode. In the oscillating mode, the differential pair of transistors are cross-coupled so that a gate terminal of one transistor (M1) is coupled to a drain terminal of the other transistor (M2), and vice versa, and the drain terminals are coupled to the crystal (X1) to generate the crystal oscillation signal. In the start-up mode, the kick-start circuit (12) drives the gate terminals of the transistors (M1, M2) with said pulses. This crystal oscillator circuit has a decreased start-up time compared to prior art solutions and a reduced influence of parasitic oscillations.
    Type: Application
    Filed: March 13, 2015
    Publication date: July 12, 2018
    Inventors: Anna Karin Stenman, Stefanos Stefanidis, Lars Sundström, Tahmineh Torabian Esfahani