Noise and nonlinearity limitations of time-to-voltage based time-to-digital converters

In this paper, the main noise contributors and their effect on single-shot precision are analysed. The TDC analysed here is based on the Nutt method, i.e. the TDC comprises of a clock counter combined with two interpolators, which are either time-to-voltage converters or dual-slope converters. We identify the main noise sources in a time-to-voltage converter and provide analytical estimations of measurement uncertainty due to these noise sources. This paper also provides estimates for single-shot precision due to finite output resistance of the time-to-voltage converter. Furthermore, a simple calibration procedure is presented to provide unbiased estimates of the parameters that minimise the squared measurement error.