A PHASE LOCK LOOP WITH AN R-C OSCILLATOR

摘要

A phase-locked-loop circuit includes an oscillator having R-C networks that are coupled to a positive feedback path of the oscillator. An amplifier having a controllable gain is included in the positive feedback path. Variation of the gain of the amplifier produces a corresponding variation in the frequency of the oscillator. A pair of differentially symmetrical signals are produced in the positive feedback path and combined in a differential amplifier to form an oscillatory signal.