| 摘要 |
PURPOSE:To remarkably increase the sensitivity, by adding the circuit in which the output and the phase difference show non-linear characteristics to the digital type phase comparison circuit. CONSTITUTION:The reference signal is inputted to the R terminal of the RSFF type phase comparison circuit 1 and the comparison signal to the S terminal, and the non-linear type integration circuit consisting of the switching circuit 3, resistor 4 and capacitor 5 is added to the output. With this circuit constitution, taking the reference signal as the waveform a and the comparison signal as the waveform b, the waveform at the output point c of the circuit 1 is as the waveform c. Further, taking the time constant of charging and discharge of the charging and discharge circuit as tauc, taud, and the repetitive period of the reference signal as T, and taking taud<T<=tauc, the output point d is the waveform d. But, when the phase difference phi between the reference signal and the comparison signal is made smaller and the switching element 3 is used so that the charge of the capacitor c can almost completely be the region to be discharged, the phase difference phi and the DC output voltage are non-linear, and the sensitivity of the phase comparator can rapidly be increased with 7/4pi<2pi-0<2pi. |
