Measurement of the exponential signal distortion

In the ADC test is convenient to use as stimulus the real exponential voltage than the sinusoidal one. Indeed, the real exponential voltage is much more similarity to the theoretical one than the sinusoidal signal. For the estimation of the final uncertainty in the ADC test, the knowledge of the distortion of the exponential stimulus needs. The distortion is caused by the exponential signals superimposed to the waited one. With this aim, in the paper is pointed out (i) the stand for the accurate acquisition of the real exponential voltage generated by capacitor discharge, and (ii) the numerical procedure to evaluate the parameters of the assigned number nP of exponential functions that best fit the acquired samples. Results of tests assess that the reconstruction error is lower than the resolution of the acquisition stand.