Very high-precision clock module controlled by a reference signal and comprising a system for checking phase integrity

Abstract

A clock module includes a main precision oscillator generating a first clock signal of a predetermined frequency, a receiving module receiving a time reference and providing a time reference signal controlling the main oscillator, and a detector for detecting a failure of the main oscillator or of the time reference signal. The detector includes: a second oscillator not controlled by the clock module and delivering a second clock signal of predetermined frequency; and a processor configured to measure a first phase difference between the first clock signal and the time reference signal, a second phase difference between the first clock signal and the second clock signal, and a third phase difference between the time reference signal and the second clock signal. The processor is configured to calculate calculating derivatives of the first order of the three phase differences measured so as to determine respective variations of the three phase differences.