A1.5-bit DFT Analyzer

In this article, it is shown how to estimate thefrequency response function of a linear system using a three-leveldigital-to-analog converter (DAC) and a 1-bit analog-to-digitalconverter (ADC). Estimation requires the usage of a three-levelperiodic stimulus signal and a sinewave, used as a dither signalto improve the effective resolution of the 1-bit ADC. By asuitable choice of the source sequence, the proposed procedureis robust to nonlinearities in the used DAC and allows detectionof nonlinearities affecting the linear filter output. This articleillustrates the main idea, its theoretical aspects, the system designparameters, and simulation and experimental results, obtainedin the case of a passive low-pass filter.

Publication year:2020