Analogue generator producing controlled high-frequency clock signal on basis of low-frequency clock signal, comprising electronic devices including sampler connected in phase-locked loop

摘要

The generator (30) comprises a frequency divider (32), a phase comparator (34) delivering the control signals (UP, DOWN), a sampler (35), a voltage generator (36) delivering the control voltage (VCK), and an oscillator (30) delivering the high-frequency clock signal (CKHF) whose frequency depends on the control voltage; the devices are connected in series, and the output of the oscillator is connected to the input of the frequency divider forming the phase-locked loop, and also to the clock input of sampler. The precision of generator can be substantially increased by connecting a separate oscillator (40) to the clock input of sampler. The sampler (35) delivers the sampled control signals (UPech, DOWNech) to the voltage generator (36), which delivers the control voltage (VCK) as a function of the sampled control signals. The sampler (35) contains a counter receiving a validation signal and delivering a sampling signal when the number of counted pulses reaches a set number, and the counter is reset when it reaches another set number; two logic gates receiving the sampling signal on one input and each one of the control signals on the other input, and delivering the samples control signals; and a third logic gate receiving the two control signals and delivering the validation signal. The period of sampling signal is less than or equal to the desired period.