Decreasing the sensitivity of ADC test parameters by means of wobbling

In this paper we propose a new technique, wobbling, for the stabilization of spectral ADC-test parameters with respect to offset and amplitude deviations of the sinusoidal stimulus. Wobbling aims at removing the effect of the rounding operation that takes place in an ADC, so that the measured harmonic distortion and noise amplitude can be truly ascribed to the intrinsic non-linearity and noise of the ADC. We compare the wobbling technique with subtractive and non-subtractive noise dithering, both from a performance and an implementation point-of-view. We present results of simulations and measurements validating the wobbling technique for use in a production environment.