PLL signal input arrangement - has input divided into separate paths for adjustment of proportional integral and derivative terms

摘要

The phase locked loop circuit is used to make adjustment to give a wide regulating range without the need for switching resistors and capacitors. The transfer element (21) between the phase comparator and the controlled oscillator has at least two paths for the incoming signal (delta phi). These paths correspond with separate terms in the transfer function of the circuit. Typically each path is controlled by an electronic switch (10,11) to select one of several current sources (8,9). The switches are remote controlled. Each path is connected to an input of an operational amplifier (70) which recombines the signal paths. With the electronic switches (10,11) the terms of the transfer function can be individually adjusted as desired.