| 摘要 |
PURPOSE:To continuously change the phase of an output signal by establishing synchronization between a reference input signal and the output signal in a state that a voltage applied by a variable voltage source is canceled by the output voltage of a phase comparator. CONSTITUTION:A voltage controlled oscillator 13 is provided to change an output frequency corresponding to a control voltage, which is applied from a voltage adder 12, and to output a signal to an output terminal 200, and a phase comparator 10 is provided to compare the phase of the output signal from the voltage controlled oscillator 13 with the phase of the reference input signal from an input terminal 100 and to generate a voltage corresponding to the difference between the both phases. Then, a variable voltage source 11 is provided to change the output voltage according to control from an external part and to output the voltage to the voltage adder 12. Further, the voltage adder 12 is provided to add the output voltage of the phase comparator 10 and the output voltage of the variable voltage source 11 and to generate a control voltage to be applied to the voltage controlled oscillator 13. Thus, since the output voltage of the variable voltage source 11 is changed as needed, the phase of the output signal can continuously be changed corresponding to a voltage change. |
