APPARATUS AND METHOD FOR VCO CALIBRATION USING FAST FREQUENCY COMPARISON BASED ON PHASE MANIPULATION

摘要

An apparatus and a method for calibrating a Voltage Controlled Oscillator (VCO) using a fast frequency comparison based on phase manipulation are provided. The calibrating apparatus includes a phase shifter for comparing an input reference frequency and an input divided frequency and shifting a phase of the reference frequency to make the phase of the reference frequency align with a phase of the divided frequency; a frequency comparator for determining which one of the phase-shifted reference frequency and the divided frequency is higher; and a cap-bank control for determining a frequency to use based on a comparison result of the frequency comparator.