资源描述:
《电子技术专业英语教学课件作者何茗unit2.ppt》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、Unit2AnalogCircuitsAnalogcircuitsoperatewithcurrentsandvoltagesthatvarycontinuouslywithtimeandhavenoabrupttransitionsbetweenlevels.Generallyspeaking,analogcircuitsarecontrastedwithdigitalcircuitsthatfunctionasthoughcurrentsorvoltagesexistedonlyatoneofasetofdiscretelevels,alltransitionsbet
2、weenlevelsbeingignored.Sincemostphysicalquantities,e.g.,velocityandtemperature,varycontinuously,asdoesaudio,ananalogcircuitprovidesthebestmeansofrepresentingthem.下一页返回Unit2AnalogCircuitsHowever,digitalcircuitsareoftenpreferredbecauseoftheeasewithwhichtheiroutputscanbemanipulatedbycomputer
3、s,andbecausedigitalsignalsaremorerobustandlesssubjecttotransmissionerrors.Therearespecialanalogtodigitalanddigitaltoanalogcircuitstoconvertfromonetypeofsignaltotheother.下一页上一页返回Unit2AnalogCircuitsThecircuitsinthisunitmakeuseofIC,orintegratedcircuit,components.Suchcomponentsareactuallyne
4、tworksofinterconnectedcomponentsmanufacturedonasinglewaferofsemiconductingmaterial.Integratedcircuitsprovidingamultitudeofpre-engineeredfunctionsareavailableataverylowcost,benefitingstudents,hobbyistsandprofessionalcircuitdesignersalike.Mostintegratedcircuitsprovidethesamefunctionalityas“
5、discrete”semiconductorcircuitsathigherlevelsofreliabilityandatafractionofthecost.Usually,discretecomponentcircuitconstructionisfavoredonlywhenpowerdissipationlevelsaretoohighforintegratedcircuitstohandle.下一页上一页返回Unit2AnalogCircuitsPerhapsthemostversatileandimportantanalogintegratedcircui
6、tforthestudenttomasteristheoperationalamplifier,orop-amp.Essentiallynothingmorethanadifferentialamplifierwithveryhighvoltagegain,op-ampsaretheworkhorseoftheanalogdesignworld.Bycleverlyapplyingfeedbackfromtheoutputofanop-amptooneormoreofitsinputs,awidevarietyofbehaviorsmaybeobtainedfromthi
7、ssingledevice.Manydifferentmodelsofop-ampsareavailableatalowcost,butcircuitsdescribedinthisunitwillincorporateonlycommonlyavailableop-ampmodels.下一页上一页返回Unit2AnalogCircuitsBasicanalogcircuitsResistance:Resistancecanbedefinedasthecharacteristicofamediumthatopposesfl