| 摘要 |
PROBLEM TO BE SOLVED: To prevent malfunctions when the fluctuating range of a voltage control oscillator is large in an oscillation circuit, in which the change of the position of the changing point of an input signal for a signal outputted by a voltage control oscillator is detected, and frequencies are matched. SOLUTION: A frequency rate to be detected by first and second frequency rate detecting circuits 6 and 7 is defined as being K times. When the frequency of the output terminal FOUT of an oscillator 5 is becomes more than K times as large as that of a signal inputted to a comparison signal input terminal 8, a signal from the output terminal FCT of the second frequency rate detecting circuit 7 is outputted to a second signal adder 4, and the oscillator 5 receives the output of the second signal adder 4 and decreases the frequencies to be outputted. On the other hand, when the frequency of the output terminal FOUT of the oscillator 5 is turned into less than 1/K times as large as that of the signal inputted to the comparison signal input terminal 8, a signal from the output terminal FCT of the first frequency rate detecting circuit 6 is outputted to a first signal adder 3, and the oscillator 5 receives the output of the first signal adder 3, and increases frequencies to be outputted. |
