Patents Assigned to Ibtel Corporation
  • Patent number: 6914490
    Abstract: A method for controlling a phase-locked loop includes receiving a frequency change signal and electrically isolating a VCO control node of the phase-locked loop from at least one charge pump of the loop. During this isolation period, the VCO control node voltage is held at a constant value equal to the voltage that existed before the frequency change signal was received. One or more parameters of the PLL are then altered in a manner that will ensure generation of a newly desired output frequency. These parameters include but are not limited to a feedback divider value and a reference frequency input into the PLL. The new output frequency may be above or below the pre-change signal frequency depending, for example, on a mode of operation of a host system. When the VCO control node is once again electrically connected to the charge pump, the PLL locks on to the desired output frequency.
    Type: Grant
    Filed: May 29, 2003
    Date of Patent: July 5, 2005
    Assignee: Ibtel Corporation
    Inventors: Eyal Fayneh, Ernest Knoll