| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact charge pump circuit, which prevents the terminal voltage from being largely deviated from a desired potential for each comparison frequency to suppress a spurious component as a result and provides approximately equal spurious characteristics in a dynamic range of a control voltage, and a compact PLL frequency synthesizer circuit which uses it. SOLUTION: Variable resistors 2 and 6 are provided in parallel with constant current source circuits 3 and 7 of a charge pump circuit 1 respectively, and electric resistances of variable resistors 2 and 6 are changed on the basis of a control voltage inputted to a voltage controlled oscillator 27.
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