Digital spectra of non-uniformly sampled signals: theories and applications. IV. Measuring clock/aperture jitter of an A/D system

A method, based on asynchronous spectral averaging, to measure the standard deviation of a clock/aperture jitter of an A/D (analog-to-digital) system is proposed. A sine wave with frequency f ₀ is used as an input test signal to a B-bit A/D system. Spectral averaging is then performed on many asynchronously acquired data records with length N. The jitter standard deviation can then be calculated from the measured signal-to-noise floor ratio. An expression which relates the signal-to-noise floor ratio to the standard deviation of the jitter is derived in a closed form. Simulation results are also presented and are shown to be in very good agreement with the theoretical results