| 摘要 |
PROBLEM TO BE SOLVED: To allow for highly accurate phase control of a polyphase clock by a clock generation circuit, while maintaining the frequency of polyphase clock constant.SOLUTION: A clock generation circuit outputting a polyphase clock includes a ring oscillator having a plurality of inverter circuits in annular connection, and outputting each clock having a delay time that is given based on a delay control signal from each inverter circuit, a first divider circuit for dividing the frequency of an injection clock by a first value and outputting as a reference clock, a second divider circuit for dividing the frequency of an injection clock by a second value and outputting as a comparison clock, and a frequency comparator for comparing the frequencies of the reference clock and comparison clock, and outputting the delay control signal based on the comparison results. The ring oscillator is configured to adjust the delay time based on the delay control signal.SELECTED DRAWING: Figure 1 |
