Assessment of Nonlinearities for Precision DACs

One may identify two independent sources of nonlinearities in digital-to-analog converters: (i) deviations at input sources and switches and (ii) nonidealities in the posterior summation circuit. The first are described by specific figures of merit, mainly integral nonlinearity and differential nonlinearity; the second, in terms of standard amplifier performance (e.g., total harmonic distortion, and so on). Performance is assessed without considering prior separation of the two, resulting in misleading characterization. We address the cross influence of (i) and (ii), and propose a novel figure of merit for bandpass response that separately addresses nonlinear deviations and memory effects attending to DACs inner structure.