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1

DAC testing using impulse signals

Vedral J., Fexa P.

Metrology and Measurement Systems

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2012

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Vol. 19, nr 1

105-114

EN

The Multi-Tone (MT) signal with uniform amplitudes can be used for DAC testing. This paper shows an easier way to generate a MT signal using several impulse signals. The article also analyzes qualities of methods for testing the dynamic parameters of Digital to Analog Converters using an impulse signal. The MT, Damped Sine Wave (DSW) and Sinx/x (SINC) signals will be used as the source for these tests. The Effective Number of Bits (ENOB) and Signal to noise and distortion (SINAD) are evaluated in the frequency domain and they are modified using the Crest Factor (CF) correction and compared with the standard results of the Sine Wave FFT test. The first advantage of the test using an impulse signal is that you need fewer input parameters to create the band signal for testing the DAC. The second one is to reduce the testing time using a band signal in comparison with multiple tests using a single sine wave.

2

Metal detector excited by frequency-swept signal

Svatoš J., Vedral J., Fexa P.

Metrology and Measurement Systems

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2011

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Vol. 18, nr 1

57-67

EN

This paper describes the theoretical background of electromagnetic induction from metal objects modelling. The response function of a specific case of object shape - a homogenous sphere from ferromagnetic and nonferromagnetic material is introduced. Experimental data measured by a metal detector excited with a linearly frequency-swept signal are presented. As a testing target various spheres from different materials and sizes were used. These results should lead to better identification of the buried object.

3

DAC testing using modulated signals

Fexa P., Verdal J., Svatoš J.

Metrology and Measurement Systems

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2011

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Vol. 18, nr 2

283-293

EN

This document analyses qualities of methods used for testing dynamical parameters of Digital-to-Analog Converters (DAC) using a multi-frequency signal. As the source for these signals, Amplitude Modulated (AM) and Frequency Modulated (FM) signals are used. These signals are often used in radio engineering. Results of the tests, like Effective Number of Bits (ENOB), Signal-to-Noise and Distortion (SINAD), are evaluated in the frequency domain and they are compared with standard results of Sine Wave FFT test methods. The aim of this research is firstly to test whether it is possible to test a DAC using modulated signals, secondly to reduce testing time, while estimating band performance of DAC.

4

Methods for economical test of dynamic parameters ADCs

Vedral J., Fexa P., Svatoš J.

Metrology and Measurement Systems

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2009

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Vol. 16, nr 1

161-170

EN

This paper describes two methods for economical test of dynamic parameters ADCs. First method is Exponential Fit Test, second method is Wobbler Test. Common testing methods are mentioned as far the accuracy and time necessary for the complete test are concerned. The tests for fast evaluation of the dependence of an effective number of bits on frequency of input signal are described and the comparison of proposed method with the standard methods is given. The suitable area of proposed method application is "each-piece" factory testing requiring extremely short time testing.