Simple Algorithm for Sampling Synchronization of ADCs

This paper describes an algorithm for synchronizing analog-to-digital converters (ADCs) to the fundamental of a continuous periodic signal. It operates like a digital phase-locked loop, is based mainly on discrete Fourier transform (DFT) on sampled data, and uses DFT-leakage detection to ensure synchronous sampling. It may be applied to distorted waveforms in general, irrespective of the type of ADC used, and no windowing functions on the sampled data need to be applied. Measurements in AC metrology in the microvolt-per-volt and microradian uncertainty levels can be done without tight hardware synchronization.