Some Techniques for Direct Digitization of Transducer Outputs
Thisapplicationnotedetailscircuittechniqueswhichdirectlydigitizethelowleveloutputsofavarietyoftransducers.
TheapproachesdescribedareuniqueinthattheydonotutilizeanyDCgainstage.ThetransduceroutputsreceivenoDCsignalconditioning;A/Dconversionisdirectly
performedatlowlevel.Thecircuitsproduceaserialdataoutputwhichmaybetransmittedoverasinglewirewiththecharacteristicnoiseimmunityofdigitalsystems.eliminatingthetraditionalDCgainstage,thesecircuits
furnishadirect,economicalwaytodigitizelowleveltransduceroutputswithoutsacrificingperformance.ApplicationNote7February1985SomeTechniquesforDirectDigitizationofTransducerOutputsJimWilliamsAlmostalltransducersproducelowlevelsignals.Normally,meaninga10-bitA/DconvertermusthaveanLSBincre-highaccuracysignalconditioningampliersareusedtomentofonly30μV.Performinga10-bitconversiononaboosttheseoutputstolevelswhichcaneasilydrivecables,typeKthermocouplemonitoringa0°Cto60°Cenvironmentadditionalcircuitry,ordataconverters.Thispracticeraisesprovesevenmorestringent.ThetypeKthermocouplethesignalprocessingrangewell
