| 摘要 |
PROBLEM TO BE SOLVED: To provide a phase synchronization circuit and a clock generation circuit capable of keeping stability even in the case of low precision like a resistance element constituting an IC circuit. SOLUTION: The phase synchronization circuit consists of a phase comparator 1, a bias current supplying circuit 2, a charge pump 3, a loop filter 4, a voltage/ current converter 5, a current control oscillator 6 and a frequency divider 7. The comparator 1 detects the phase difference between a reference signal fref and the output fosc of the divider 7 and drives the next-stage charge pump 3 as UP and DN signals. The charging/discharging current of the pump 3 is decided by the circuit 2. As voltage smoothed by the filter 4, the output of the pump 3 is inputted to the converter 5 to be converted to a current output and drives the oscillator 6. The stability of the device including resistance 17 and resistance 12 is secured by the circuit 2 and the converter 5.
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