×

Apparatus and methods for tuning a voltage controlled oscillator

  • US 9,042,854 B2
  • Filed: 12/09/2013
  • Issued: 05/26/2015
  • Est. Priority Date: 11/04/2005
  • Status: Active Grant
First Claim
Patent Images

1. An auto-tuning circuit for tuning a voltage controlled oscillator (VCO) during a coarse tuning mode, the auto-tuning circuit comprising:

  • a prescaler circuit configured to receive a VCO clock signal from the VCO and to generate a divided clock signal, the prescaler circuit having a selectable division ratio;

    a counter module including a first counter and a second counter, the first counter configured to operate with the second counter to control a value of the selectable division ratio of the prescaler circuit, the counter module configured to receive a division control signal M and the divided clock signal, and to generate a phase-frequency detector (PFD) feedback signal based on the division control signal M and the divided clock signal; and

    a digital processing logic circuit configured to receive the divided clock signal, the digital processing logic circuit including a cycle counter configured to count a number of cycles of the divided clock signal generated by the prescaler circuit that occur during a calibration interval, the digital processing logic circuit further configured to set a value of a capacitor array control signal based on the number of cycles counted.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×