A new spectral analysis method for analog-to-digital converter (ADC) dynamic parameters testing is presented. ADC characterization by spectral analysis has traditionally been done with discrete Fourier transform, which imposes restrictions to optimize results; one of these is coherent sampling. This paper uses resampling methods to change the sampling rate by a noninteger factor and estimates the ADC dynamic parameter like signal-to-noise and distortion ratio, in noncoherent sampling. The effectiveness of resampling methods is proven on both simulation and experiment results.