L. Gasparini, D. Macii, M. Gottardi, D. Fontanelli
This paper deals with a data acquisition system based on a low-power digital sensor for image contrast detection. This system is suitable for geometric pattern recognition as well as for event monitoring. Possible applications are: surveillance, people access monitoring, and road lines recognition in car-like vehicles. The adopted imager was developed by the Fondazione Bruno Kessler (FBK), Trento, Italy, and it is particularly useful whenever the available energy budget and the channel communication bandwidth are too limited to use common video cameras. Since neither the standard testing...
Miroslav Kamenský, Karol Kovác, Gabriel Války
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...
Dominique Dallet, Dario Petri, Daniel Belega
The paper investigates and compares the performances of two state-of-the-art MultiHarmonic Sine Fitting (MHSF) algorithms when used in the dynamic testing of an Analog-to-Digital Converter (ADC). The influence of the initial estimate of the test signal frequency on the uncertainty of the estimated ADC dynamic parameters is analyzed by using computer simulations. Moreover, the accuracies of the considered MHSF algorithms and the sine-fit algorithms suggested in the existing standards for ADCs testing are compared by means of both computer simulations and experimental results.
Bengt E. Jonsson
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.
Serena Porrazzo, Francesco Cannillo, Chris van Hoof
This paper presents a procedure for the power-optimal design of high-resolution low-bandwidth switched-capacitor (SC) ΔΣ modulators (ΔΣMs). The most power efficient ΔΣ architecture is identified among single-loop switched-capacitor (SC) feedback (FB) and feed-forward (FF) topologies with different loop order N , oversampling ratio OSR , and quantizer resolution B . Based on the results obtained, an experimental prototype is implemented in a 0.18 µm CMOS process, achieving a signal-to-noise ratio (SNR) of 95 dB over a signal bandwidth f BW of 10 kHz. The prototype operates with a 1.28 MHz...
Z. Jelassi, D. Dallet, C. Rebai B. Le Gal, Ch. Jego
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....
Salim Alahdab, Reza Lotfi, Wouter A. Serdijn
An ultra-low-power, low-noise sensor interface IC for pacemakers is presented. The proposed architecture is designed to achieve small chip area and a good trade-off between power consumption and noise figure by using current-mode operation. The IECG signal, from 50 mHz-100 Hz, is first filtered by a bandpass filter. Subsequently, the signal output of the filter is converted into a current by a nonlinear transconductance (Gm) cell. The output of the Gm-cell is digitized by a nonlinear 8-bit 1 kS/s Current-mode Successive Approximation ADC to compensate for the nonlinearity of the Gm-cell. The...
M. Catelani, L. Ciani, S. Giovannetti, A. Zanobini
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...
Brian Fitzgibbon, Michael Peter Kennedy, Franco Malobertiy
This paper discusses a bus-splitting technique for hardware reduction in error feedback digital delta-sigma modulators (DDSMs). The technique is based on error masking and is applied to DDSMs with sinusoidal inputs. We consider the components that contribute to the output signal-to-noise ratio in conventional DDSMs and review new architectures for implementing the digital algorithms without sacrificing performance.
Martin Sekerák, Linus Michaeli, Ján Šaliga, A. Cruz Serra
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...