Digitally controlled oscillator, using a switchable element, application to the production of devices for recovering the tempo and phase of a digital signal

摘要

The oscillator comprises a circuit with oscillating loop, an electrical element 20 which is inserted into the circuit and whose presence modifies the frequency of the oscillator, and analog switching means 22 provided in order to switch this element 20, thus enabling the frequency of the oscillator to take one or the other of two values Fmax and Fmin. The switching means are controlled by a binary digital input signal DC which enables the oscillator to deliver a signal whose average frequency depends on the density of the 1 logic states with respect to the 0 logic states of the input signal. <IMAGE>