Alcatel Cit

Compagnie Industrielle Des Telecommunicat.

Andre Lankar

Alain Lalanne

The present invention relates to a digital servo-control system whose purpose is to control very high precision equipment. The system includes two digital-to-analog converters, one of which is followed by a divider, with the two converters contributing to producing a control signal. A processor responds to a measurement signal and to a reference value to generate the digital values that are delivered to the converters. The system is particularly suitable for application to servo-controlling a voltage-controlled oscillator.

Digital servo-control system

A timebase adapted to be synchronized to an external clock comprises at least one generator incorporating a voltage-controlled oscillator adapted to be controlled by the result of comparing an external synchronization signal from an external clock with an output signal of the timebase. Each generator comprises at least one differential comparator receiving the external synchronization signal and the timebase output signal. It drives a summing circuit on the input side of the control input of the oscillator of the generator in question. The generator further comprises a calibration system comprising a threshold detector connected to the output of the phase comparator, a calibration voltage adjustment circuit connected between the threshold detector and a second input of the summing circuit, and a trigger circuit in and controlling the adjustment circuit.

Growing community of inventors

Paris, France

Andre Lankar