Use of analog-to-digital sigma-delta conversion technology in digital multi-channel...

( )Engineering Information Abstracts Part II 99

ditioning hardware to convert the thermocouple junction’smillivolt values into signals compatible with the input channels

Ž .of the data acquisition DA hardware. If the thermocouple isremote from the DA hardware, a transmitterrreceiver pairmust be used to prevent loss of information or introduction ofnoise. These adjustments permit the thermocouple’s operatingrange to be scaled to use the full dynamic range of the analog

Ž .to digital converter ADC in the DA system. After the ADCunits are converted by software routines into output voltagevalues, algorithms are used to generate temperature readings.1 Refs. In English EI Order Number: EIP98014009848Keywords: Thermocouples; Data acquisition; Analog to digitalconversion; Computer software; Algorithms; Computer hard-ware; Signal processing

Title: USE OF ANALOG-TO-DIGITAL SIGMA-DELTA CON-VERSION TECHNOLOGY IN DIGITAL MULTI-CHANNELELECTROCARDIOGRAPHS

( )Author s : Kurikov, S.F.; Prilutskij, D.A.; Selishchev, S.V.Corporate Source: Moskovskij Gosudarstvennyj Inst Elektron-noj Tekhniki, Moscow, RussiaSource: Meditsinskaya Tekhnika n 4 July-Aug 1997. p 7-10CODEN: MEDTBV ISSN: 0025-8075Publication Year: 1997

Ž .Abstract: The Sigma - Delta analog-to digital converters ADCŽ .have a high resolving power above 12 bits , they are largely

based on the signal digital filtration principles, which maymoderate requirements for the analog filtration of signals anduse DC amplifiers as alternatives to instrument ones. Forelectrocardiograph operation, the Sigma - Delta ADC of an

Ž .AD 7716 Analog Devices with 22 bits were used in thisstudy. The use of Sigma - Delta ADC in the electrocardio-graphs has been shown to be a rather useful alternative oftraditional ADC. Moreover, Sigma - Delta ADC may be alsouseful for other systems for collecting and processing biomedi-cal signals which are close in their requirements for a fre-quency range and a dynamic range, i.e. encephalographic,myographic, rheographic and other input signals. 28 Refs. InRussian EI Order Number: EIP98013998330Keywords: Electrocardiography; Analog to digital conversion;Biomedical equipment; Patient monitoring; Performance;Computer aided diagnosis; Digital devices

Title: DIGITAL COMMS REQUIRE DYNAMIC PERFOR-MANCE

( )Author s : Bernel, David A.; Hofner, Tanja C.Corporate Source: Maxim Integrated Products

Ž .Source: Electronic Engineering London v 69 n 849 Sep 1997.p 67-68, 70-71 CODEN: ELEGAP ISSN: 0013-4902Publication Year: 1997Abstract: The complex, high-frequency signal of state-of-the-art communication applications are generally down-convertedin the analogue domain, digitized and then filtered and de-modulated in the digital domain. The techniques of digitalsignal processing are also employed to recover the modulateddata. Whether an application requires undersampling or over-sampling, the ArD converter must deliver high levels of

dynamic performance. The overall system specifications willdepend on the ADC’s dynamic performance parameters such

Ž .as thermal noise, spurious-free dynamic range SFDR , totalŽ . Ž .harmonic distortion THD , and signal-to-noise ratio SNR .

In English EI Order Number: EIP97113925805Keywords: Digital communication systems; Demodulation;Signal to noise ratio; Signal distortion; Analog to digitalconversion; Fast Fourier transforms; Thermal noise; Digitalsignal processing

Title: BUILD A SMART ANALOG TRANSMITTER WITH AMU C AND LOW-POWER COMPONENTS

( )Author s : O’Grady, Albert; Ryan, JimCorporate Source: Analog Devices, Limerick, IrelSource: EDN v 42 n 19 Sep 12 1997. p 135-138, 142-143CODEN: EDNSBH ISSN: 0012-7515Publication Year: 1997Abstract: Factors to be considered in designing a low-poweranalog transmitter are discussed. Serial interfacing is notbecoming a standard in smart-transmitter applications due toits flexibility, low signal line count, and the ease with whichyou can incorporate isolation into the design. Another keyelement in selecting the front-end ADC power is power con-sumption. Issues to be considered when selecting a suitablemicroC for a smart transmitter are outlined. In English EIOrder Number: EIP97103896289Keywords: Transmitters; Microprocessor chips; Electric cur-rent control; Electric power supplies to apparatus; Digital

Žcommunication systems; Communication channels informa-.tion theory ; Industrial applications; Transducers; Analog to

digital conversion; Low pass filters

Title: NEW ENCODING SCHEME FOR HIGH-SPEEDFLASH ADC’S

( )Author s : Kaess, F.; Kanan, R.; Hochet, B.; Declercq, M.Corporate Source: Swiss Federal Inst of Technology, Lau-sanne, SwitzConference Title: Proceedings of the 1997 IEEE International

Ž .Symposium on Circuits and Systems, ISCAS’97. Part 1 of 4Conference Location: Hong Kong, Hong Kong ConferenceDate: 19970609-19970612Source: Analog Circuit and Signal Processing Neural SystemsProceedings - IEEE International Symposium on Circuits andSystems v 1 1997. IEEE, Piscataway, NJ, USA,97CH35987. p5-8 CODEN: PICSDI ISSN: 0271-4310Publication Year: 1997Abstract: A new encoding scheme for high-speed flash analogto digital converters using a Wallace tree is described. Itprovides a global error filtering and its regular topology op-timises the signal propagation. Its application to a 5-bit 1.4-GHz Gallium Arsenide analog-to-digital converter is de-

Ž .scribed. Author abstract 7 Refs. In English EI Order Num-ber: EIP97093822603Keywords: Signal encoding; Electric converters; Analog todigital conversion; Semiconducting gallium arsenide; Com-parator circuits; Signal detection; Signal filtering and predic-tion