Clock-signal regenerator comprising a crystal oscillator incorporated in a phase-locked loop.

摘要

The frequency of a voltage controlled crystal oscillator can be pulled in the conventional way by means of a varicap diode forming the load capacitance of the oscillator crystal. In oder to realise a wider range of frequency pulling, the load capacitance 44 is alternately switched on and off in a known manner. According to the invention a band-switch diode 46 can be utilised as a switch element, if the hole-storage time of this diode is as long as or longer than the oscillator cycle. By means of a low-frequency control voltage on the diode it is rendered self-switching within the oscillator cycle so that proportional frequency tuning is possible.