Adaptive CADC optimisation, modelling and testing (original) (raw)
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Measurement, 2017
An integrated analytical approach to improve the performance of adaptive sub-ranging analog-to-digital converters (ADCs) in both pre-threshold phase and post-threshold phase of their operation is presented and discussed. The differentia specifica of the adaptive ADCs, discriminating them from conventional subranging ADCs, is the method of forming output codes of converted samples. The adaptive ADCs employ simple internal digital processing units (DPUs) to compute the output codes, which creates the conditions for optimization of the conversion algorithm and improvement of their effective number of bits (ENOB) beyond ENOB of their conventional counterparts. Previous researches led to development of two main groups of conversion algorithms used in adaptive ADCs, however none fully satisfactory. A new, hybrid conversion algorithm for the adaptive ADCs that combines the most desired features of each of the two groups of algorithms is proposed and investigated in this paper. It provides the greatest possible rate of increase of ENOB per cycle of conversion in the first, pre-threshold phase of conversion, and enables further increase of ENOB in the following, post-threshold phase.
Optimal design of adaptive cyclic ADC
2004
The goal of the paper is presentation of a new approach to optimization and design of the cyclic (subranging) adaptive analog-to-digital converters (CADC). Particularity of approach is application of the signalprocessing algorithm for estimates (codes) of the input samples computing. Solution of optimization task determines the conditions improving CADC's resolution and speed of conversion till upper boundaries achievable under given probability of saturation in each cycle.
General approach to simulation analysis of sub-optimal cyclic A/D converters functioning and design
The paper deals with the general approach to modeling and simulation analysis of sub-optimal adaptive cyclic analogue-to-digital converters (CADCs). Both principles and methods for carrying out simulation investigations of CADC functioning, as well as their application areas, are considered. Some examples of simulation researches performed using developed CADC models and corresponding software, including comparison of proposed sub-optimal adaptive CADCs with existing patterns of conventional cyclic ADCs and comparison of CADC testing methods, are presented. The efficiency of simulation as a reliable, convenient and low-cost tool significantly simplifying and accelerating analysis and design of CADCs is also shown.
Design and Analysis of the Laboratory Prototype of Sub-optimal Adaptive CADC
The paper presents backgrounds and particularities of design and practical realization of sub-optimal adaptive cyclic analogue-to-digital converter (CADC). The realization problems which appeared during design process and the ways of their solving are discussed. The results of hardware experiments with laboratory prototype of sub-optimal adaptive CADC using developed in this order measurement stand are also presented.
Principles of optimisation, modelling and testing of intelligent cyclic A/D converters
Measurement, 2006
The goal of the paper is a discussion of possibilities, methods and results of application of the optimal signal processing technique to design and optimisation of the cyclic A/D converters (CADC). New effects appearing in CADC computing the codes of the input samples using optimal signal processing algorithms and long-word binary arithmetic, are analysed. There is shown that the intelligent CADC (ICADC) built on this principle most efficiently utilise the resources of their analogue and digital parts, and their performance may achieve theoretically available upper boundaries. Analytical expressions for upper boundaries of sub-optimal ICADC resolution, speed of conversion and information capacity are presented. Principles of ICADC computer analysis and assessment of their performance, as well as the questions of practical implementation of the converters are discussed.
A bs trac t-The paper presents the toolbox for simulation analysis and support of the high-level design of new adaptive sub-ranging analog-to-digital (A/D) converters whose digital parts allow the iterative calculation of output codes using digital estimation algorithms. The developed appropriate methods and simulation tools enable the assessment of the converters characteristics taking into consideration many different non-idealities (e.g. offsets, noises, non-linearities, gain mismatches) of the internal components of ADCs. The simulation analysis can support the proper choice of the suitable converter configuration and tuning of parameters of the conversion algorithm, which enables to achieve the best characteristics of the converters under assumed level of errors of the components. The toolbox can be used at initial stages of design of the adaptive sub-ranging A/D converters to preliminary evaluation of the expected performance and its comparison with the performance of the existing comparable sub-ranging A/D converters.
New Effective Architectures and Conversion Algorithms for Adaptive Sub-ranging A/D Converters
A bs trac t-The paper is devoted to the new effective architectures and conversion algorithms used in adaptive sub-ranging analog-to-digital converters (ADCs) whose digital parts allow the iterative calculation of output codes using digital estimation algorithms. Two classes of adaptive sub-ranging ADCs, i.e. recursive (cyclic) and pipeline ADCs, are considered in the paper. The paper develops the earlier research on the adaptive sub-ranging ADCs and removes the crucial disadvantages of these converters simplifying their architectures, i.e. decreasing significantly the high resolution of internal D/A sub-converters and very large values of internal amplifiers gains. The appropriate new conversion algorithms and the results of simulation experiments which compare ADC employing the proposed converter with the existing pipeline ADC are presented and discussed.
Information properties of sub-optimal cyclic ADC with algorithmic estimates forming
The goal of the paper is ńe analysis of resolution and informdion characteristics of a new class of suboptinral cvclic analoguc-to-digital conveńers (CADC) wiń the adaplve algorithmic e §titnates forming. These converters differ fron the other ADC by complex hardware and softlvare optimisation peńormcd using tlre extended algoritlrms derived in [ 1,2'|, Thc results of optinrisation ensure the improvement of resolution and speed of convcrsion till the values unachiwable for ońer versions of converters. The conncction between cADc resolution and infonrration capacity is analysed. There is shown ńat complex optimisation of CADC ensure § full utilisation of ńeir information capacity undcr guarantced small probability ofthe rough enors ofconversion. Kel,rvords: adaptive cvclic ADC, extended algorithms of conversion, infonnation capactty of CADC.
Evolution of architectures and conversion algorithms in adaptive sub-ranging A/D converters
Photonics Applications in Astronomy, Communications, Industry, and High-Energy Physics Experiments 2014, 2014
The paper presents the survey of architectures and conversion algorithms used in so called adaptive analog-to-digital converters considered during the studies on these converters carried out by the author and his colleagues. The key idea that distinguishes the adaptive analog-to-digital converters from other sub-ranging converters consists in application of the iterative digital signal processing algorithm for calculation of the output codes of the converters and for calculation of the values of residue signal gains in subsequent steps of conversion. Application of this approach in the proposed converters allows to achieve better parameters of the converters in comparison with parameters of conventional subranging analog-to-digital converters.