OSCILLATOR AND METHOD FOR SETTING OSCILLATION FREQUENCY OF THE SAME

摘要

In an oscillator provided with a first programmable divider which obtains a reference signal by dividing the frequency of the oscillating signal of a piezoelectric vibrator by a frequency dividing number M, a PLL circuit section which operates upon inputting the reference signal as an input signal and obtains a multiplied signal by multiplying an input signal by the second frequency dividing number N of a second programmable divider installed to a feedback circuit, and a third programmable divider which can divide the frequency of the multiplied signal by a third frequency dividing number X and outputs the divided frequency, the frequency dividing numbers M, N, and X can be independently set at different values. Since the infinite combinations of the numbers M, N, and X can be utilized, the kinds of frequences which can be generated from one oscillator can be sharply expanded by making an appropriate combination selectable. Therefore, the oscillator can cover a wide range of frequencies by using a crystal resonator which can stably exhibit its ability and can be manufactured at a low cost. In addition, an oscillator which can be delivered in a short period at a low cost can be provided, because the crystal resonator can be utilized as an oscillating source even when the frequency modulation of the resonator is not performed.