Patents Assigned to X Integrated Circuits B.V.
  • Patent number: 5905388
    Abstract: The invention relates to a circuit for frequency synthesis, comprising: a digital controlled oscillator, comprising (a) a clock generator; an accumulator circuit to which the signal from the clock generator is fed; and a control digit feed circuit for feeding to the digital oscillator a signal representing a control digit; and (b) a phase-locked loop which is connected to the carry output terminal of the accumulator circuit and which is provided with a phase detector, a low-pass filter and a controlled oscillator, wherein the carry output terminal is connected to the phase detector. The digital controlled oscillator is preferable adapted to generate a signal representing a remainder, wherein a correction circuit is arranged for deriving a correction signal from the remainder. The correction circuit is connected to a combination circuit connected to one of the inputs of the phase detector or to a combination circuit incorporated in the phase-locked loop. The circuits can also be connected in cascade.
    Type: Grant
    Filed: September 26, 1997
    Date of Patent: May 18, 1999
    Assignee: X Integrated Circuits B.V.
    Inventors: Robertus L. Van Der Valk, Robertus J. Dequesnoy, Johannes H. A. De Rijk, Menno T. Spijker