Phase comparator and synchronizing signal extracting device

A phase comparator comprising:

• a phase comparing portion for generating a leading phase instructing pulse and a lagging phase instructing pulse to mate a phase of an input pulse train and a phase of an input clock signal with each other in accordance with the phases;
• a correction pulse generating portion for generating a correction pulse in accordance with the input pulse train and the input clock signal;
• a resetting portion for resetting the phase comparing portion by generating a reset pulse in accordance with the leading phase instructing pulse and the lagging phase instructing pulse output from the phase comparing portion, the correction pulse output from the correction pulse generating portion, and the input clock signal;
• and
• a pulse correcting portion for removing false pulses contained in the lagging phase instructing pulse output from the phase comparing portion, based on the correction pulse output from the correction pulse generating portion.

A synchronizing signal extracting device comprising:

• a phase comparator including,
• a phase comparing portion for generating a leading phase instructing pulse and a lagging phase instructing pulse to match a phase of an input pulse train and a phase of an input clock signal with each other in accordance with the phases;
• a correction pulse generating portion for generating a correction pulse in accordance with the input pulse train and the input clock signal;
• a resetting portion receiving the leading phase instructing pulse and the lagging phase instructing pulse output from the phase comparing portion, the correction pulse output from the correction pulse generating portion, and the input clock signal for resetting the phase comparing portion by generating a reset pulse;
• a differentiator for differentiating a pulse train having a frequency that is ½ of a frequency of the input pulse train, and supplying to the phase comparator as the input pulse train;
• a charge pump unit for increasing a voltage value of an output voltage signal by executing a charging operation when the leading phase instructing pulse is input from the phase comparator, and decreasing the voltage value of the output voltage signal by executing a discharging operation when the lagging phase instructing pulse is input from the phase comparator;
• and
• a voltage-controlled oscillator for receiving the voltage signal output from the charge pump unit, generating the input clock signal having a frequency that increases as the voltage value of the voltage signal increases, and supplying the input clock signal to the phase comparator.

A synchronizing signal extracting device comprising:

• a phase comparator including,
• a phase comparing portion for generating a leading phase instructing pulse and a lagging phase instructing pulse to mate a phase of an input pulse train and a phase of an input clock signal with each other in accordance with the phases;
• a correction pulse generating portion for generating a correction pulse in accordance with the input pulse train and the input clock signal;
• a resetting portion for resetting the phase comparing portion by generating a reset pulse in accordance with the leading phase instructing pulse and the lagging phase instructing pulse output from the phase comparing portion, the correction pulse output from the correction pulse generating portion, and the input clock signal;
• a pulse correcting portion for removing false pulses contained in the lagging phase instructing pulse output from the phase comparing portion, based on the correction pulse output from the correction pulse generating portion;
• a differentiator for differentiating a pulse train having a frequency that is ½ of a frequency of the input pulse train, and supplying to the phase comparator as the input pulse train;
• a charge pump unit for increasing a voltage value of an output voltage signal by executing a charging operation when the leading phase instructing pulse is input from the phase comparator, and decreasing the voltage value of the output voltage signal by executing a discharging operation when the lagging phase instructing pulse is input from the phase comparator;
• and
• a voltage-controlled oscillator for receiving the voltage signal output from the charge pump unit, generating the input clock signal having a frequency that increases as the voltage value of the voltage signal increases, and supplying the input clock signal to the phase comparator.