Statistical efficiency of synchronous time-to-digital converters

In this paper, the Cramér-Rao Lower Bound (CRLB) on the variance of time interval duration estimators is derived for synchronous Time-to-Digital (TDC) converters, based on a coarse counter, keeping into account the effect of noise affecting the TDC clock period. The model has been validated using Montecarlo analysis. By comparing the CRLB to the variance of the TDC output, also theoretically modeled together with the estimator mean value and bias, the statistical efficiency of the considered TDC architecture has been demonstrated.