UDC 621.317.1: 621.3.087.92
RECOGNIZING NONLINEAR COMPONENT OF MEASUREMENT SIGNAL BY LINKED HISTOGRAMS DURING ADC METROLOGICAL TESTS
А. M. Abramov, PhD (in technical sciences), associate professor, department of information measurement and biomedical equipment, RSREU, Ryazan, Russia;
orcid.org/0009-0006-7274-5206, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
The task to find the contribution of nonlinear component of measurement signal (MS) during metrological tests to ADC integral nonlinearity is considered. The aim of the work is to determine ADC integral and differential nonlinearities by means of a new method, which reduces the requirements to reference measuring instruments in terms of accuracy class by taking into account MS nonlinear component. For this purpose, periodic MS of triangular shape, level-shifted downward MS and level-shifted upward MS are successively fed to the input of tested ADC. The first histogram of ADC code distribution is plotted in the absence of MS offset, second and third histograms are plotted in the case of MS downward and upward shifting. After that, for each ADC code in the second and third histograms with the help of the first histogram the authors construct two equations leading to a single one and solve the obtained systems of equations at MS offset down and up by the least squares method, determining MS offset and the contribution of MS nonlinear component to integral nonlinearity for each ADC code. Considering MS nonlinear component, integral nonlinearity for each ADC code is determined, and then differential nonlinearity of ADC is determined from integral nonlinearity.
Key words: : measurement signal, offset, nonlinear component, integral nonlinearity, differential nonlinearity, analog-to-digital converter, histogram, least squares method, conversion functio