标签: 简化adc

Integratinganalog-to-digitalconverters(ADCs)featuringbinary-codeddecimal(BCD)outputsfordisplayinterfaceofferanumberofexcellentfeatures,aswellashighresolution,ataverylowcost.Theseadvantagesincludeauto-zeroing,sign-magnitudecoding,noiseaveraging,andhighimpedanceinputsandarealsoattrac-tiveformicroprocessor-basedsystems.Unfortunately,manydisplay-orientedADCsaredifficulttointerfaceduetothemulti-plexedBCDformatoftheoutputs.Anexceptionisthe4-1/2digitTC7135ADC,whichprovidesa"strobe"output.AN785SimplifyA/DConverterInterfacewithSoftwareAuthors:GaryGrandboisandWesFreeman,INTERFACEHARDWAREMicrochipTechnology,Inc.ThecompleteTC7135-to-18255AhardwareinterfaceisshowninFigure1.TheonlydigitstrobeusedisDS5(MSD),andtheBUSYoutputisignored.TounderstandwhytheotherdigitstrobesarenotINTRODUCTION……