Circuit for generating an output phase signal with a variable phase shift relative to a reference phase

摘要

A circuit generating an output phase signal with an optionally variable phase shift relative to a reference phase. It includes an oscillator (10) outputting phase signals at n outputs, each of which differs in phase by phi=360°/n. These phase signals are applied selectively via multiplexers to a phase interpolator, at the output of which the signal changed in phase relative to a reference phase. The output phase signal is generated in a charging circuit in which a capacitor can be varied by signaling current sources ON/OFF with the aid of phase switches in accordance with the phasing to be produced for the output signal. To avoid jitter in the transition from one phase to another separating switches are inserted in the connection between the current sources and the charging circuit, these separating switches being controlled so that they are never open at the same time.