Phase locked loop having control circuit for automatically operating VCO on an optimum input/output characteristic

摘要

A phase locked loop (1) including an oscillator (5), usually made as a voltage controlled oscillator (VCO), arranged to operate selectively according to different input/output characteristics. The circuit further includes a control circuit (81) for selectively controlling the operation of the oscillator (5) thereby making the oscillator (5) itself operate on one of an optimum characteristic selectively determined according to the operating conditions of the loop (1).