94EE247

EECS247Lecture1:Introduction©2007H.K.Page1EECS247Analog-DigitalInterfaceIntegratedCircuits©2007Instructor:HaidehKhorramabadiUCBerkeleyDepartmentofElectricalEngineeringandComputerSciencesLecture1:IntroductionEECS247Lecture1:Introduction©2007H.K.Page2Instructor’sTechnicalBackground•Ph.D.,EECSdepartment-UCBerkeley1985,advisorProf.P.R.Gray–Thesistopic:Continuous-timeCMOShigh-frequencyfilters•Industrialbackground–11yearsatATT&BellLaboratories,N.J.,intheR&Dareaasacircuitdesigner•Circuitsforwirelinecommunications:CODECs,ISDN,andDSLincludingADCs(nyquistrate&over-sampled),DACs,filters,VCOs•Circuitsintendedforwirelessapplications•Fiber-opticscircuits–3yearsatPhilipsSemiconductors,Sunnyvale,CA•ManagedagroupintheRFICdepartment-developedICsforCDMA&analogcellphones–3years@BroadcomCorp.–DirectorofAnalog/RFICsinSanJose,CA.•Projects:Gigabit-Ethernet,TVtuners,andDSLcircuitry–CurrentlyconsultantforICdesign•Teachingexperience–Hastaught/co-taughtEE247@UCBsince2003–InstructorforshortcoursesofferedbyMEADElectronics–AdjunctProf.@RutgersUniv.,N.J.:TaughtagraduatelevelICcourseEECS247Lecture1:Introduction©2007H.K.Page3Administrative•Coursewebpage:~EE247–Coursenoteswillbeuploadedonthecoursewebsitepriortoeachclass–Homeworks&duedatesarepostedonthecoursewebsite–Pleasevisitcoursewebsiteoftenforannouncements•Lecturesarewebcastmainlyforthebenefitofstudents@UCSC–Pleasetrytoattendtheclasseslivetobenefitfromdirectinteractions–MakesureyouusetheprovidedmicrophoneswhenaskingquestionsorcommentinginclassEECS247Lecture1:Introduction©2007H.K.Page4OfficeHours&Grading•Officehours:–Tues./Thurs.2:30-3:30pm@563CoryHall(unlessotherwiseannouncedintheclass)–Extraofficehoursbyappointment–Feelfreetodiscussissuesviaemail:[e-mail]•Coursegrading:–Homework/project50%–Midterm20%(tentativedate:Oct.18)–Final30%EECS247Lecture1:Introduction©2007H.K.Page5Prerequisites&CADTools•Prereqs.–Basiccourseinsignalprocessing(Laplaceandz-transform,discreteFouriertransform)i.e.EE120–Fundamentalcircuitconceptsi.e.EE105andEE140•CADTools:–HSPICEorSpectre–MatlabEECS247Lecture1:Introduction©2007H.K.Page6Analog-DigitalInterfaceCircuitryDigitalProcessorAnalog/DigitalInterfaceAnalogInputAnalogWorldDigital/AnalogInterface001110010100110100010AnalogOutput•Naturallyoccurringsignalsareanalog•Toprocesssignalsinthedigitaldomain∴NeedAnalog/Digital&Digital/AnaloginterfacecircuitryQuestion:Whynotprocessthesignalwithanalogcircuitsonly&thuseliminateneedforA/D&D/A?EECS247Lecture1:Introduction©2007H.K.Page7CMOSTechnologyEvolutionversusTime*Ref:PaulR.GrayUCBEE290course‘95InternationalTechnologyRoadmapforSemiconductors,@(VGS-Vth=0.5V)7580859095’00’05’106u3u2u1.5u1u0.8u0.6u0.35u0.25u0.13u0.1u110100ft[GHZ]Year0.18u0.065u0.045uEECS247Lecture1:Introduction©2007H.K.Page8CMOSDeviceEvolutionProgressionfrom1975to2005•Featuresizes~X1/100•Cut-offfrequencyft~X300•Minimumsizedevicearea~1/L2•Numberofinterconnectlayers~X8EECS247Lecture1:Introduction©2007H.K.Page9ImpactofCMOSScalingonDigitalSignalProcessingDirectbeneficiaryofVLSItechnologydownscaling–Digitalcircuitsdealwith“0”&“1”signallevelsonlyÆNotsensitiveto“analog”noise–SiArea/functionreduceddrasticallydueto•Shrinkingoffeaturesizes•Multimetallevelsforinterconnections(currently8metallevelv.s.only1inthe1970s)–Enhancedfunctionality&flexibility–Amenabletoautomateddesign&test–“Arbitrary”precision–ProvidesinexpensivestoragecapabilityEECS247Lecture1:Introduction©2007H.K.Page10AnalogSignalProcessingCharacteristics•Sensitiveto“analog”noise•Hasnotfullybenefitedfromtechnologydownscaling:–SupplyvoltagesscaledownaccordinglyÆReducedvoltageswingsÆmorechallenginganalogdesign–ReducedvoltageswingsrequiresloweringofthecircuitnoisetokeepaconstantdynamicrangeÆHigherpowerdissipationandchiparea•Notamenabletoautomateddesign•Extraprecisioncomesatahighprice•RapidprogressinDSPhasimposedhigherdemandsonanalog/digitalinterfacecircuitryÆPlentyofroomforinnovations!EECS247Lecture1:Introduction©2007H.K.Page11Cost/FunctionComparisonDSP&Analog•Digitalcircuitry:FullybenefitedfromCMOSdevicescaling–Cost/functiondecreasesby~29%eachyear™Cost/functionX1/30in10years*•Analogcircuitry:NotfullybenefitedfromCMOSscaling–DevicescalingmandatesdropinsupplyvoltagesÆthreatenanalogfeasibility™Cost/functionforanalogcktalmostconstantorincrease¾Rapidshiftoffunctionimplementationfromprocessinginanalogdomaintodigital&henceincreasedneedforA/D&D/Ainterfacecircuitry*Ref:InternationalTechnologyRoadmapforSemiconductors,©2007H.K.Page12DigitallyAssistedAnalogCircuitry•Analogdesignhasindeedbenefitedfromtheavailabilityofinexpensiveon-chipdigitalcapabilities•Examples:–Compensating/calibratingADC&DACinaccuracies–Automaticfrequencytuningoffilters&VCOs–DCoffsetcompensationEECS247Lecture1:Introduction©2007H.K.Page13Example:DigitalAudio•Goal-Losslessarchivalandtransmissionofaudiosignals•Circuitfunctions:–Preprocessing•Amplification•Anti-aliasfiltering–A/DConversion•ResolutionÆ16