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US 8,284,887 B2Granted
Clock data recovery circuit and multiplied-frequency clock generation circuit
AssigneeSony Corporation
InventorsHidekazu Kikuchi, Hideo Morohashi, Tomokazu Tanaka
Life of this patent
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Abstract
Disclosed herein is a clock data recovery circuit including: a first phase detector; a loop filter; a charge pump; a voltage-controlled oscillator; a second phase detector; a phase correction information generation section; and a phase correction information addition section.
Claims9
A clock data recovery circuit comprising:
- a first phase detector configured to detect a difference in phase between input data and a clock signal extracted from said input data and generate signals each representing an analog quantity corresponding to said difference in phase;
- a loop filter configured to indirectly integrate and smooth said signals output by said first phase detector;
- a charge pump configured to supply an electrical charging current to said loop filter in accordance with a specific one of said signals output by said first phase detector or draw an electrical discharging current from said loop filter in accordance with another one of said signals output by said first phase detector;
- a voltage-controlled oscillator configured to generate said extracted clock signal vibrating at a frequency determined by a voltage output by said loop filter;
- a second phase detector configured to detect the polarity of said difference in phase between said input data and said extracted clock signal;
- a phase correction information generation section configured to generate phase correction information to be used for eliminating a phase offset of said first phase detector in accordance with detection results produced by said second phase detector;
- and
- a phase correction information addition section configured to add said phase correction information generated by said phase correction information generation section to a feedback loop including said first phase detector, said loop filter, said charge pump and said voltage-controlled oscillator,
- wherein said phase correction information addition section increases or decreases said electrical charging current supplied from said charge pump to said loop filter and decreases or increases said electrical discharging current drawn from said loop filter to said charge pump.
6 more elements
A multiplied-frequency clock generation circuit comprising:
- a first phase detector configured to detect a difference in phase between input clock and a multiplied-frequency clock signal and generate signals each representing an analog quantity corresponding to said difference in phase;
- a loop filter configured to indirectly integrate and smooth said signals output by said first phase detector;
- a charge pump configured to supply an electrical charging current to said loop filter in accordance with a specific one of said signals output by said first phase detector or draw an electrical discharging current from said loop filter in accordance with another one of said signals output by said first phase detector;
- a voltage-controlled oscillator configured to generate said multiplied-frequency clock signal vibrating at a frequency determined by a voltage output by said loop filter;
- a frequency divider configured to divide said frequency of said multiplied-frequency clock signal generated by said voltage-controlled oscillator in order to result in a divided frequency and output a divided-frequency clock signal having said divided frequency to said first phase detector;
- a second phase detector configured to detect the polarity of said difference in phase between said input clock and said multiplied-frequency clock signal;
- a phase correction information generation section configured to generate phase correction information to be used for eliminating a phase offset of said first phase detector and said frequency divider in accordance with a detection result produced by said second phase detector;
- and
- a phase correction information addition section configured to add said phase correction information generated by said phase correction information generation section to a feedback loop including said first phase detector, said loop filter, said charge pump, and said voltage-controlled oscillator,
- wherein said phase correction information addition section increases or decreases said electrical charging current supplied from said charge pump to said loop filter and decreases or increases said electrical discharging current drawn from said loop filter to said charge pump.
7 more elements
Dependencies are inferred from the claim text.