| 摘要 |
<p>PURPOSE: To oscillate a frequency to be synchronized with the value of any frequency by comparing an externally impressed frequency with a self-oscillation frequency through a comparator and controlling the oscillation frequency of an oscillator corresponding to the compared value. CONSTITUTION: The phase of a frequency signal F1 impressed from the outside is compared with the phase of a frequency signal F2, for which a frequency signal to be oscillated under the control of a a microcomputer MC is multiplied for 1/N, by a phase comparator PC and afterwards, the compared value is made into constant DC voltage by a low-pass filter(LPF). The DC voltage based on the phase compared value is compared with a voltage, for which a reference voltage VREF is distributed to resistors for distribution, by comparators COM 5 and COM 6 constituted as a comparing means. Corresponding to the outputs of the comparators COM 5 and COM 6, the microcomputer MC controls the oscillation frequency of a voltage frequency oscillator VCO.</p> |
