| 摘要 |
PROBLEM TO BE SOLVED: To shorten the stabilization time of oscillation frequency at the time of an intermittent operation and to reduce the power consumption by providing a switching circuit controlled to a conductive state when control signals supplied to a control terminal are on and controlled to be sufficiently high impedance, when they are off between an input terminal and a resonance part. SOLUTION: The switching circuit 10 to be the conductive state when the control signals supplied to the control terminal 11 are on and to be the sufficiently high impedance, when the control signals are off is provided between the input terminal 3 and the resonance part 1 and a voltage holding capacitance 12 for holding a voltage applied to a voltage-controlled variable capacitance 5, while the switching circuit 10 is off is provided. Then, in the case of performing the application to a circuit for performing the intermittent operation for example, by turning off the control signals, when an allocated time slot is ended and the intermittent operation is to be started, the switching circuit 10 is controlled to be off prior to the start of a control voltage generation circuit and the application voltage of the voltage-controlled variable capacitance 5 is maintained at a value at the time of an operation by the electric charge of the voltage-holding capacitance 12. |
