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Page 739 of 936 Results 7381 - 7390 of 9356

Jan Holub, Josef Vedral, Miroslav Kubín
IMPROVEMENT OF STEP-GAUSS ADC STOCHASTIC TEST METHOD

Improvement of Analog-to-Digital Converters testing method that is suitable for testing of high-resolution AD converters (e.g. Σ-Δ or dither-based) or on the contrary ultra high-speed AD converters is presented. The method is based on the histogram test driven by stochastic signal with defined probability density function. By repeating of the test for different settings of band-pass filter that is inserted to the input testing signal path it is possible to obtain an estimation of frequency dependency of effective number of bits. The results have to be recalculated to equivalent band-pass filtering. Practical demonstration confirmed wider applicability than for direct band-pass filter application.

M. Fonseca da Silva, A. Cruz Serra
A NEW ROBUST FOUR PARAMETER SINE FITTING PROCEDURE

In this paper a new procedure to perform four parameters sine fitting is presented in a closed form, ready for standardization. This new procedure grants convergence of the algorithm, even in those cases where the traditional techniques tend to converge to local minimums of the error function.
This new procedure can also be used to compute the initial values for the traditional four parameters sine fitting algorithm if very high accuracy is required. In such case convergence of the traditional algorithm is also assured.

Y. C. Jenq, Qiong Li
DIFFERENTIAL NON-LINEARITY, INTEGRAL NON-LINEARITY, AND SIGNAL TO NOISE RATIO OF AN ANALOG TO DIGITAL CONVERTER

The Analog to digital converter (ADC) has been widely used in all kinds of modern electronic instruments, so it is desirable to find out the relationship between various errors and the performance of ADC and improve the performance with a low cost operation. This paper studies and tries to quantify the relationship between the differential non-linearity (DNL) error, the integral non-linearity (INL) error and the signal to noise ratio (SNR) performance of an ADC, and investigates various methods to reduce the effect of these errors to increase the SNR. Major results are obtained by computer simulation, while a simple analytic model is also investigated. It is found that the loss of SNR due to DNL roughly follows the “6 dB per LSB” rule, and the major cause of the significant SNR loss is primarily due to harmonic distortion introduced by the INL. The investigation of the analytic model of the INL shows that it can predict the SNR loss very similar to the result obtained by computer simulation. We also study various methods to improve the SNR performance of the ADC. It is found that the Midpoint method, although simple, can almost completely eliminate the effect of the INL. It is also shown that if the ratio of the sampling frequency to the input signal frequency is large, the DNL can be further reduced to improve the SNR by Grouping and Sorting method.

R A Belcher, C Asteriou, C J Bury, A Edwards, R Hall, G Lancelin, M Penny
A DSP BASED TEST SYSTEM FOR 'NOISE-SEPARATION' MEASUREMENTS ON ADC AND DAC SYSTEMS

This paper describes the design and application of a 'noise-separation' test system that uses in-system programmable logic devices and a digital signal processor. This offers a low cost approach to multi-tone testing of the wide-bandwidth linearity of both ADC and DAC systems. As the test signal bandwidth is software configurable and uses 1 bit D-A converters it can be applied to a much wider range of applications than more conventional multi-tone test methods. Time-domain processing is expected to provide meaningful results for routine tests in a much shorter time than with FFT analysis.

António Cruz Serra
NEW TRENDS IN ANALOG TO DIGITAL CONVERTERS TESTING

In this paper, new state of the art analog-to-digital converters (ADCs) testing techniques both static and dynamic are revised and discussed.
Regarding the static test it is shown that a new technique based on the use of small triangular waves superimposed with a variable offset value as input signal, reduces dramatically the test duration. This histogram based technique can be implemented by using low cost generators even for high resolution ADC testing.
In relation to the dynamic test, a variant of the traditional histogram test using Gaussian noise as stimulus signal is discussed. It allows the test of high frequency, or high resolution ADCs in those cases where the traditional sinusoidal stimuli are not available with the required spectral purity. New techniques to grant convergence of the traditional four-parameter sine fitting algorithms traditionally used in time domain tests are also revised.

Franco Maloberti
HIGH-SPEED HIGH-RESOLUTION DATA CONVERTERS FOR BASE STATIONS: TECHNOLOGIES, ARCHITECTURES AND CIRCUIT DESIGN

This paper presents a possible evolution of base station architectures in the frame of the future global communication scenario. Moving from such a view the paper considers the technology trend and its influence on highspeed data converter design. Then, architectures of highspeed, high-resolution converters are resumed. Finally, design techniques and strategies for achieving the requirements of base-station systems are discussed.

Jan Saliga, Linus Michaeli, Roland Holcer
NOISE INFLUENCE ON EXPONENTIAL HISTOGRAM ADC TEST

This paper deals with some error effects caused by additive noise at analog-to-digital converters (ADCs) testing based on the histogram method and the exponential shape of input testing signal. The histogram method with exponential signals has been an alternative test method for ADC developed by the author. Here, the theoretical analysis of some errors in estimation of code bin width and quantisation levels caused by additive input Gaussian noise is performed. The theoretical results are verified by simulations. The acquired results are compared with the analogues ones for sinewave and Gaussian noise input test signals.

A.A. Platonov, L.M. Malkiewicz, K. Jedrzejewski
ADAPTIVE CADC OPTIMISATION, MODELLING AND TESTING

Analytical approach to optimization, analysis, modeling and testing of the adaptive cyclic (sub-ranging) analog-to-digital converters (CADC) is considered. The particularity of the approach is digital computing the estimates (codes) of the input signal samples using optimal signal - processing algorithm. Upper boundaries for resolution, speed of conversion, and information characteristics are determined. Methodic of advanced CADC model-based simulation investigations is presented. The efficiency of simulation experiments as reliable, convenient and low-cost tool significantly simplifying and accelerating the search for optimal variants, design and analysis of CADC is shown.

Bruno Andò, Salvatore Baglio, Vito Caruso, Nicola Pitrone
A SYSTEM FOR THE CHARACTERIZATION OF THE MICRO-CONTROLLERS

The characterization of complex electronic devices is very important for technical as well as didactic reasons. The characterization of the micro-controllers involves the investigation on its peripheral devices, mainly the ADCs, the PWMs, the timer signals, sometimes the DACs. A testing platform has been realised, with reference to the ST52X430 micro-controller. Moreover, it has been improved in order to test the peripheral devices of the ST52X440 micro-controller. It consists of a board and some programmable instruments connected to a PC, on which the implemented software can run. The user can choice the test to be performed on the basis of the IEEE standard 1241-2001. Some results of the ADC characterization made by using this platform have been presented last year. In this work the use of the realised system for the characterization of the other peripheral devices is presented.

Henrik Lundin, Patrick Svedman, Xi Zhang, Mikael Skoglund, Peter Händel, Per Zetterberg
ADC IMPERFECTIONS IN MULTIPLE ANTENNA WIRELESS SYSTEMS—AN EXPERIMENTAL STUDY

This paper investigates some of the effects that ADC imperfections may have on wireless communication systems. First, an experimental communication system for wireless multiple-input multiple-output (MIMO) is described. In this test bed, an ADC behavioural model has been implemented. The resulting performance of the communication system, in terms of bit error rate, is assessed when the parameters of the ADC model are altered. The results show that, for this system, the ADC resolution is the key parameter while the non-linearity errors are of minor importance.

Page 739 of 936 Results 7381 - 7390 of 9356