双斜率ADC的精确校准

用模拟开关配置获取零点和量程输出代码的正确安装。

Maxim>AppNotes>AnalogSwitchesandMultiplexersKeywords:A/Dconverters,ADCs,A/Dconvertercalibration,offsetflipping,handhelddevicesJan13,2011APPLICATIONNOTE4539PreciseCalibrationofDual-SlopeADCsAbstract:ThiscircuitcalibratesADCson-the-fly,usinganalogswitchestoconfigurethesetupproperlyforobtainingthezeroandspanoutputcodes.AsimilarversionofthisarticleappearedintheDecember31,2007issueofEETimesmagazine.Handhelddevicesformeasuringtoxicgas,bloodglucose,etc.areincreasinglypopular,andtheirlowcosthasmadethemthrowawaydevices,tobediscardedwhenthebatteryorthesensorexpires.Typicaldevicesincludealithium(Li)primarycell,asensor,anA/Dconverter(ADC),conditioningci