| 摘要 |
PURPOSE:To obtain an excellent phase comparator which operates securely at an ECL level by composing a phase difference detecting circuit of ECL and employing a current control type integrating circuit. CONSTITUTION:When a frequency signal TS1 leads a frequency signal TS2, the phase difference detecting circuit 18 composed of the ECL raises a pulse signal H to a level H by the phase, and the switch S1 of the integrating circuit 19 is turned on to charge a capacitor C4 positively. The pulse signal U is held at a level L to turn off the switch S1 in other periods, and the capacitor C4 is discharged through a resistance R5. The output of the integrating circuit 19 is outputted through an amplifying circuit 20. On the other hand, when the frequency signal TS2 leads the frequency signal TS1, the capacitor C4 is charged negatively through a switch S2 by the phase difference and discharged through a resistance R5 in other periods. |
