Dynamic testing of analog-to-digital converters by means of the sine-fitting algorithms
Résumé
The chapter is dedicated to dynamic testing of Analog-to-Digital Converters (ADCs) by means of both time- and frequency-domain sine-fitting algorithms (SFAs). At first the sine-fitting procedure used for the estimation of SIgnal-to-Noise And Distortion ratio (SINAD) and Effective Number Of Bits (ENOB) parameters is described. In the following the expressions for the bias and the standard deviation of the ENOB estimator provided by a SFA are derived. Then, the SFAs based on the Interpolated Discrete Fourier Transform (IpDFT) method, the Energy-Based (EB) method, and the well known three- and four-parameter SFAs are separately analyzed. For each algorithm, the basic theoretical background and the operational detail are given. Moreover, the accuracy of all the presented algorithms are compared by means of both theoretical and simulation results. Some aspects concerning the influence of the harmonics, time jitter, and time base distortions on the dynamic performance of an ADC are also discussed. Besides, some Multi-Harmonics Sine-Fitting Algorithms (MHSFAs) are briefly described. Finally, the accuracy of the ENOB estimates provided by the considered SFAs and MHSFAs are compared through real-world data.