Equivalent Number of Bits of Major ADC Types Considering the Evaluation of Their Dynamic Error

Abstract

Data on the equivalent (real) number of bits of an analog-to-digital converter (ADC), taking into account its operating conditions, makes it possible to make the optimal choice of ADC at the early stages of designing analog-to-digital control systems. The article shows that the real number of bits is determined by the signal delay times in the ADC and the time sampling frequency of the signals converted into the ADC, which depends on the cutoff frequency of the characteristic of the spectral density of the converted signal. The analysis carried out during the research made it possible to obtain specific dependences of the delay times of the converted signals in the ADCs under consideration. The article gives a comparative assessment of the influence of the time characteristics of three types of sequential ADCs (sequential count, push-pull integration, successive approximation) on the equivalent number of bits of the analog-to-digital conversion process.