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Vadim Geurkov
A BUILT-IN SELF-CHECK METHOD FOR MULTI-CHANNEL MEASUREMENT SYSTEMS

Signature analysis techniques have become extremely popular in digital systems testing due to such advantages as simplicity, small amount of additional circuitry, and small degree of error masking. In this paper the signature analysis techniques are applied to mixed (analog-to-digital) systems testing. The general case of multi-channel measurement system is considered.

Daniel Belega
SYSTEM FOR TESTING ANALOG-TO-DIGITAL CONVERTERS

This paper presents a system named "ADC TEST" that estimates the static and dynamic parameters of an analog-to-digital converter according to the definitions given in IEEE Standard 1241. One shows the available output graphical pages with theirs information and facilities in a practical testing application.

E. Garnier, A. Tetelin, Ph. Marchegay
CANCELLATION OF CHARGE INJECTION ERROR ON SWITCHED CURRENT DIVIDER CIRCUITS FOR ACCURATE D/A CONVERTERS

This paper proposes compensated methods to cancel the effects of charge injection error on switched-current Divider Circuits. Algorithmic structures of current dividers are presented and the final charge injection error is evaluated for each Algorithm. So, compensated methods to cancel this error are proposed.

R. Kochan, A. Sachenko, V. Kochan, N. Vasylkiv
UNIVERSAL SIGMA-DELTA ADC FOR INTELLIGENT DISTRIBUTED INSTRUMENTATION

In this papers the precision single-board, 8 channels, 24 bit sigma-delta ADC with on-line remote reprogramming mode is described. The results of experimental researches of the noise immunity of the developed ADC in real (industrial) measurement conditions are presented. The results of experimental researches of the prototype in the same measurement conditions are also considered.

Milan Štork
MODIFIED Σ-Δ VOLTAGE TO FREQUENCY CONVERTER

Voltage to frequency converter (VFC) is an oscillator whose frequency is linearly proportional to control voltage. There are two common VFC architectures: the current steering multivibrator and the charge-balance VFC. For higher linearity, the charge-balancing method is preferred. The charge balanced VFC may be made in asynchronous or synchronous (clocked) forms. The synchronous charge balanced VFC or "sigma delta" (Σ-Δ) VFC is used when output pulses are synchronized to a clock. The charge balance VFC is more complex, more demanding in its supply voltage and current requirements, and more accurate. It is capable of 16 to 18 bit linearity.
Σ-Δ modulator can be used for synchronous VFC (SVFC). The synchronous behaviour is good in many applications, but the output of SVFC is not a pure tone (plus harmonics) like a conventional VFC, but it contains components harmonically related to the clock frequency. The SVFC produces a change in probability density of output pulses N and N+1 clock cycles after the previous output pulse.
In this paper, the modified SVFC (MSVFC) is described. This MSVFC works similarly as conventional SVFC but it has a pure tone on output (for constant input voltage). Therefore, it is possible to measure the period of MSVFC output (this does not work for SVFC).

J.J. Ocampo Hidalgo, A. Garcia Ortiz, L. D. Kabulepa, M. Glesner
ANALYSIS AND DESIGN OF A 4th ORDER BANDPASS SIGMA DELTA MODULATOR FOR GSM COMMUNICATIONS STANDARD

This work addresses the design of a 4th order bandpass sigma delta modulator (BPSDM) for IF AD converters suitable for second generation cellular standards such as GSM. The resonator architecture of a BPSDM can be derived from the transfer characteristic of a lowpass modulator by means of mathematical transformations. It can be observed that each transformation results in a different cascade of resonators (COR). Therefore different values of performance metrics like SNR, dynamic range, robustness against circuit non-idealities and SFDR can be expected. Behavioral simulations at the architectural level were carried out to find the COR that best meets the requirements imposed by the GSM communications standard and minimizes requirements of the sub-circuits used in the chosen architecture. A BPSDM was designed and sent to fabrication, using a 0.3 µm, double polysilicon, triple metal, N-well CMOS technology. Simulation results are showing that the proposed prototype reaches a SNR of 85 dB and a sampling rate of 80 MHz.

F. Adamo, F. Attivissimo, N. Giaquinto
MATLAB TOOLBOXES FOR A/D CONVERTERS CHARACTERIZATION


Mustafa Keskin, Matthew E. Brown, Un-Ku Moonm, Gábor C. Temes
A VOLTAGE-MODE SWITCHED-CAPACITOR BANDPASS ΔΣ MODULATOR

A novel fourth-order voltage-mode switched-capacitor bandpass ΔΣ modulator, using direct-charge-transfer pseudo-N-path resonators, is described. This modulator is insensitive to component mismatches and finite opamp bandwidth, and is also less sensitive to finite opamp gain than previous bandpass ΔΣ data converters. It is therefore suitable for high-speed communications applications.

Tadeusz Zloto, Zygmunt Biernacki, Marek Kurkowski, Pawel Ptak
COMPUTER-AIDED SYSTEM FOR MEASURING TEMPERATURE OF ROTATING ELEMENTS

The paper includes a review of currently used devices for measuring temperature of rotating parts of machines. In the subsequent section it describes a computeraided measuring system developed by the authors. Using the optoelectronic measuring path, the system is employed for measuring temperature of cylinder block of an axial multipiston pump.
Besides, the application of DasyLab software package for the above mentioned measurements is presented.

Marek Kurkowski, Zygmunt Biernacki, Tadeusz Zloto, Pawel Ptak
SIGNAL GENERATION AND ACQUISITION IN THE CORRELATION WTS

The paper deals with problems of signal analysis. Examples of system modelling by means of Dasylab package are discussed.
Measurements, analysis and visual presentation of selected signals were performed by means of measuring card PCL818 and Dasylab package. They are also described in the present paper [7].

Page 777 of 977 Results 7761 - 7770 of 9762