Determining ADC effective number of bits via histogram testing

A new application for one of the widely known A/D converter (ADC) dynamic testing methods, namely the histogram method, is discussed. After computing the transition voltages of the ADC transfer characteristics, the effective number of bits is computed. Simulation shows that this method more accurately characterizes the ADC used for arbitrary input signals, compared to the fast Fourier transform (FFT) and sine-fit methods which characterize the ADC in the light of an input sinusoid. The technique outperforms sinewave fitting as it gives more accurate results, while avoiding convergence problems of the iterative curve fitting algorithm. The FFT method was verified to be the least accurate. Simulation indications that the histogram method is better than the sine-fit method are presented