A PROGRAMMABLE CLOCK GENERATOR THAT USES NOISE SHAPING AND ITS APPLICATION IN SWITCHED-CAPACITOR FILTERS

A programmable digital clock generator that produces a wide range of c lock frequencies with fine resolution is described, The clock generato r consists of a noise-shaping control loop and a number-controlled osc illator, The generated clock has a time-varying period, When this cloc k is used as the sampling clock in a switched-capacitor filter (SCF) t o set its frequency response, the time-varying period causes nonunifor m sampling, which is acceptable under certain conditions that are desc ribed, Measured performance of a 2-mu m CMOS implementation of the clo ck generator is presented, Also, measured data for the clock generator driving two SCF's are reported.