| 摘要 |
PURPOSE:To obtain a circuit smaller in the initial shift amount, by providing a coincidence circuit outputting a pulse having the duty factor in response to an input signal and an output of a phase shifter and a capacitor charged and discharged in response to the output pulse. CONSTITUTION:The amplitude of signals is limited at the center of waveforms (a), (b) respectively at amplitude limiters 13, 12 and a rectangular wave having 50% of pulse width duty as shown in (c) and (d) is outputted. The rectangular wave signals (c), (d) are processd that the output is on a high level only when both signal levels are coincident at a coincidence circuit 14. As for switches 16 and 17, the switch 17 is closed when the output of the circuit 14 is on a high level and a capacitor 20 is discharged with a current of a current source 19 during this period. Further, when the output of the circuit 14 is on a low level, the switch 16 is closed and the capacitor 20 is charged inversely with the current of a current source 18 during this period. The voltage across the capacitor 20 is fed back negatively to a phase shifter 11, and the amount of phase shift is varied depending on the voltage across the capacitor 20. |
