Patent ID: 6316975
Filing Date: 2001-11-13
Classification: G06K,H01Q,H03L

Abstract:
A method of determining when frequency lock occurs relative to a desired frequency, the method comprising:providing a phase lock loop including a voltage controlled oscillator configured to oscillate at a frequency which varies responsive to a voltage applied to the voltage controlled oscillator;applying the voltage to the voltage controlled oscillator to produce a frequency of oscillation less than the desired frequency;increasing the voltage applied to the voltage controlled oscillator using one or more steps of a first size;increasing the voltage applied to the voltage controlled oscillator using one or more steps of a second size smaller than the first size;decreasing the voltage applied to the voltage controlled oscillator using one or more steps of a third size smaller than the second size;increasing the voltage applied to the voltage controlled oscillator using a step of the third size; andindicating that lock has occurred in response to the increase of the step of the third size.