Abstract: The circuit comprises two substantially identical stages (8a, 8b). Each of these two stages (8a, 8b) respectively comprises an input point (10a, 10b) and an output point (11a, 11b) and is arranged to produce, at its output point (11a, 11b), a voltage having an adjustable mean value and variations which are amplified with respect to the variations in the voltage at its respective input point (10a, 10b) with a gain controlled by a gain control signal (Vcg1, Vcg2). The input point (10a) of the first stage (8a) is linked to a decoupling capacitor (30) receiving the input signal (Vin). The output point (11a) of the first stage (8a) supplies the output signal of the circuit (Vout). A comparator (40) is provided for slaving, to a reference voltage (Vref), the voltage at the output point (11b) of the second stage, as well as the mean value of the output signal (Vout).

Abstract: In the slaving process, a reference signal is sampled by a clock signal of an oscillator and then digitized. The value representative of a phase error is then deduced from the sampled and digitized signal. A correction value is then deduced from this phase error to correct a digital value representing the oscillator control voltage. The device of the invention allows this process to be implemented. The invention also relates to a voltage-controlled crystal oscillator incorporating such a device.