VCO circuit, PLL circuit using VCO circuit, and data recording apparatus the PLL circuit

A VCO circuit, comprising:

• a digital VCO comprised of,
• a phase data generator configured to receive a frequency control input in synchronization with a reference clock signal, and to generate a phase data subject to change dependent on a value of said frequency control input,
• a synchronous clock signal generator, connected to said phase data generator, and configured to receive said phase data from said phase data generator and to generate a first synchronous clock signal based on said phase data, and
• a delay quantity data generator, connected to said phase data generator and said synchronous clock signal generator, and configured i) to receive said frequency control input, said phase data, and said synchronous clock signal, and ii) to generate a first delay quantity data for delaying said first synchronous clock signal based on said frequency control input and said phase data;
• a phase modulator, connected to said digital VCO, and configured to receive said first synchronous clock signal and said first delay quantity data from said digital VCO and to output a second synchronous clock signal and a second delay quantity data based on said first delay quantity data;
• and
• a delay line, connected to said phase modulator, and configured to receive said second synchronous clock signal and said second delay quantity data from said phase modulator, and to delay said second synchronous clock signal, based on said second delay quantity data, and output said delayed second synchronous clock signal as an output clock signal,
• wherein said VCO further comprises a register, and
• wherein said phase data generator comprises i) an adder configured to add, as an addition result, the value of said frequency control input with a previously updated phase data generated by said delay quantity data generator and stored by said register, and ii) a surplus calculator, connected to said adder and configured to receive the addition result from the adder and to output, as said phase data, a remainder of a division of the addition result by a predetermined value.

A VCO circuit, comprising:

• a digital VCO, comprised of,
• a phase data generator configured to receive a frequency control input in synchronization with a reference clock signal, and to generate a phase data subject to change dependent on a value of said frequency control input,
• a synchronous clock signal generator, connected to said phase data generator, and configured to receive said phase data from said phase data generator, and to generate a synchronous clock signal based on said phase data, and
• a delay quantity data generator, connected to said synchronous clock signal generator and said phase data generator, and configured to receive said frequency control input, said phase data, and said synchronous clock signal, and to generate a delay quantity data for delaying said synchronous clock signal based on said frequency control input and said phase data;
• and
• a delay line, connected to said digital VCO, and configured to receive said synchronous clock signal and said delay quantity data from said digital VCO, and to delay said synchronous clock signal, based on said delay quantity data, and output said delayed synchronous clock signal as an output clock signal,
• wherein said VCO further comprises a register, and
• wherein said phase data generator comprises i) an adder configured to add, as an addition result, the value of said frequency control input with a previously updated phase data generated by said delay quantity data generator and stored by said register, and ii) a surplus calculator, connected to said adder, and configured to receive the addition result from the adder and to output, as said phase data, a remainder of a division of the addition result by a predetermined value.