Phase-locked loop using continuously auto-tuned inductor-capacitor voltage controlled oscillator

A phase-locked loop circuit, comprising:

• a dual-input voltage controlled oscillator having a coarse tuning input, a fine tuning input, and a clock signal output, wherein signals on the clock signal output have a changing frequency controlled by input signals;
• a frequency divider coupled to receive the output of the voltage controlled oscillator and responsive to the output of the voltage controlled oscillator to provide a frequency divided output signal;
• a phase and frequency detector that compares a reference clock with an output clock of the frequency divider and generates a charge pump control voltage;
• a charge pump coupled to the phase and frequency detector that generates a loop filter control current from the charge pump control voltage;
• a loop filter coupled to the charge pump that generates a loop filter voltage from the loop filter control current;
• a coarse-tuning linear amplifier coupled to the loop filter that generates a voltage controlled oscillator coarse-tuning voltage from the loop filter voltage;
• and
• a fine-tuning linear amplifier coupled to the loop filter that generates a voltage controlled oscillator fine-tuning voltage from the loop filter voltage.