The calculation of dynamic errors in signal transformation circuits of analog-to-digital converters for mechatronic systems

Precision and wide-band analog-to-digital converters (ADC) are used for information processing in mechatronic systems. The analog signal transformation circuits, such as sample, and hold circuit (SHC) and an analog signal interpolation circuit (ASIC), are applied with the aim of increasing the precision of converters. These circuits allow for reducing the quantity of comparators in the converter and increase their dynamic stability. The models of SHC and ASIC as well as the results of the calculation precision and dynamic parameters of such circuits are presented in this paper. Equations for the calculation of the aperture error in the Gaussian and a sinusoidal input signal were derived. The structural model, proposed for SHC, evaluates the nonlinearity of a transfer characteristic, and the influence of noise in the signal and strobe channels. The results of the theoretical research and analytical equations for the evaluation of the number of signal interpolation block differential amplifiers, which depends on the analog signal's maximal frequency and the number of segments of the converter, are presented. The results of this work allow one to estimate the main precision and dynamic parameters of ADC transformation circuits.