Pll circuit

A PLL circuit configured by a feedback loop including:

• a piece of phase detecting or frequency detecting and time-to-digital converting equipment making comparison of phases and frequencies of a reference signal and a feedback signal and converting a result of the comparison into a digital value;
• a digital loop filter removing a high frequency noise component from an output of the piece of the phase detecting or frequency detecting and time-to-digital converting equipment;
• a digitally controlled oscillator controlled based on an output of the digital loop filter;
• and
• a divider frequency-dividing an output of the digitally controlled oscillator and outputting the feedback signal,
• wherein the piece of the phase detecting or frequency detecting and time-to-digital converting equipment comprises:
• a counter measuring a phase difference between the reference signal and the feedback signal with first precision;
• and
• a delay-line measuring the phase difference between the reference signal and the feedback signal with second precision finer than the first precision.

A PLL circuit configured by a feedback loop comprising:

• a piece of phase detecting or frequency detecting and time-to-digital converting equipment making comparison of phases and frequencies of a reference signal and a feedback signal and converting a result of the comparison into a digital value;
• a digital loop filter removing a high frequency noise component from an output of the piece of the phase detecting or frequency detecting and time-to-digital converting equipment;
• a digitally controlled oscillator controlled based on an output of the digital loop filter;
• and
• a divider frequency-dividing an output of the digitally controlled oscillator and outputting the feedback signal,
• wherein the piece of the phase detecting or frequency detecting and time-to-digital converting equipment comprises:
• a first circuit converting a phase of the reference signal into digital;
• a second circuit converting a phase of the feedback signal into digital;
• and
• a subtractor obtaining a difference between outputs of the first circuit and the second circuit.