The estimation of test signal quality by means of two simple filters in ADC testing

Methods for ADC dynamic testing standardized in IEEE standards are primarily based on sampling sine wave test signal. Harmonic generator is recommended with the THD and the SNHR about 10 dB better than those of the tested ADC. However, this condition creates problems for testing state-of-the-art ADCs. This paper proposes an easy method for testing signal spectral purity. The test signal, which is passed by two simple analog filters, is measured by a common ADC, whose nonlinearity is post-corrected mathematically. The results are then compared with the common approach of applying a notch filter, and uncertainties of results are evaluated.

► Easy-to-implement method for the assessment of signal and/or ADC quality.
► Method is based on several measurements of a signal, passed through two simple passive filters and posterior computation.
► Uncertainties are determined for incoherent sampling and verified by Monte-Carlo simulations.
► Practical measurement and its verification prove the applicability and uncertainties of the proposed approach.