Normalized frequency estimation for accurate dynamic characterization of A/D converters by means of the three-parameters sine-fit algorithm

摘要

In this paper an accurate estimation procedure of the effective number of bits (ENOB) of an analog-to-digital converter (ADC) by means of the three-parameter sine-fit algorithm is proposed. It is well-known that the performance of the three-parameter sine-fit algorithm strongly depends on the accuracy of the normalized frequency [IEEE standard for terminology and test methods for analog-to-digital converters, IEEE Std, pp. 1241-2000; D. Dallet, J.M.D. Silva, Dynamic Characterization of Analog-to-Digital Converters, Springer, 2005 (Chapter 3, pp. 61-84)]. In the proposed procedure, the normalized frequency used in the three-parameter sine-fit algorithm was estimated a priori by means of the interpolated discrete Fourier transform (IpDFT) method with a Hann window. A condition associated with the number of acquired samples is derived in order to not take into account the contributions of normalized frequency estimation errors due to quantization noise. Simulations carried out confirm the effectiveness of the derived condition. Moreover, to prove the performance of the proposed procedure, some experimental results are given.