Aperiodic clock generation with spur suppression

Abstract

Aperiodic clock generation with clock spur suppression is based on cascaded randomizers, such as for mixed signal devices. A clock generator circuit includes an input node to receive the input periodic clock signal having an input-clock frequency. A first randomizer circuit coupled to receive the input clock signal from the input node, to perform signal randomization to suppress spurious signal content associated with (a) the input clock signal, and (b) the first randomizer circuit, and to generate an intermediate clock signal. A second concatenated randomizer circuit is coupled to receive the intermediate clock signal, to perform signal randomization to suppress spurious signal content associated with (a) the intermediated clock signal, and (b) the second randomizer circuit, and to generate an aperiodic output clock signal having a pre-defined average output-clock frequency that is less than the input-clock frequency. Example randomizers are a delta-sigma divider and a pulse swallower (in any order).