In the area of electromagnetic interference (EMI) time-domain EMI measurement systems significantly reduce measurement time. As EMI measurements require high dynamic range or signal-to-noise ratio and wide frequency range, a multiresolution structure of available fast sampling analog-to digital converters (ADC) is used inside such systems. The combination of several ADCs allows to increase overall dynamic range of measuring device. In the paper spectral properties of the quantization noise of system with two ADCs are analyzed by simulations as well as experimentally for harmonic input signal. Multiresolution measurements were realized by two channels of data acquisition card and PC postprocessing. The noise suppression achieved by experiments is presented.

The problem of selecting an optimally efficient ADC architecture at different resolutions is treated using a mainly empirical approach. By analyzing a large amount of measured performance data reported in the literature, the power efficiency of different ADC architectures is investigated. An efficiency hierarchy of ADC architectures is identified, and the low-power enabling features instate-of-the-art designs are summarized. The work shows that there are significant differences between architectures, and also the feasibility of an empirical approach to design optimization.

Event-driven analog-to-digital conversion, particularly level crossing A/D conversion (LC-ADC), and associated signal reconstruction techniques are still novel approaches that need further improvements to be more efficient in term of energy consumption and bandwidth resources. Among several components, this type of converter is composed of a timer block, which essentially controls the output resolution and reconstructed signal. In this paper, Authors present a level-Crossing Flash ADC (LCF-ADC) model made with Co-simulation technique where Simulink ADC model and HDL timer are associated. Besides, different interpolation algorithms are studied for signal reconstruction.

In instrumentation based on an analog-to-digital converter (ADC), the performance of data acquisition (DAQ) device has a direct impact on the performance index of the whole measurement system, so it has an important significance that research the uncertainty analysis of data acquisition board. This paper proposes an automatic measurement system based on DAQ board with automatic uncertainty evaluation of the measurement results according to the “guide to the expression of uncertainty in measurement” and its supplement. Theoretical aspects of the uncertainty analysis in high-speed multifunction data acquisition device and the LabVIEW interface carried out are analyzed and discussed.

The accuracy of Digital to Analog Converters (DACs) is becoming important proportionally to the requirement on low distortion of the generated signals. This paper presents a new method for measuring the transfer characteristics of high resolution DACs under dynamic condition. The proposed method is based on the comparison of the DAC analog output voltage with a reference signal by using a fast comparator and registration of the DAC digital input code word in the moment when the DAC analog output voltage exceeds the reference voltage. The registration of the digital input code word into a fast memory is controlled by the comparator output. The reference signal is the superposition of the DC voltage generated by the DAC and a slow dithering voltage. Its average value is measured by a precision voltmeter which secures the required metrological accuracy. After digital processing the registered sequence of digital code words is used to determine the Integralnonlinearity (INL) and the Differential-nonlinearity (DNL) of the DAC under test.