集成电路专业英语 课件 7 Analog Integrated Circuits

7AnalogIntegratedCircuitsPartIIIIntegratedCircuitDesignWhyAnalogICsMatterNotallfunctionscanberealizeddigitallyFront-endsignalconditioningisalwaysanalogHigh-speeddigitalsystemsrelyonanalogprinciplesAnalogvsDigitalProcessingAnalog:continuous-time,sensitivetonoiseanddistortionDigital:discretelevels(0/1),toleranttonoiseModernsystemscombinebothdomainsOperationalAmplifiers(Op-Amps)High-gainmulti-stageamplifiersDifferentialinput,single-endedoutputCorebuildingblockofanalogICdesignOp-AmpSymbolandTerminalsInverting(−)inputNon-inverting(+)inputOutputterminalPositiveandnegativesupplyrailsSimplifiedOp-AmpModelModeledasavoltage-controlledvoltagesourceVeryhighinputresistanceLowoutputresistanceLargeopen-loopgainOp-AmpKeyParametersInputoffsetvoltageInputbiascurrentOpen-loopgainOutputvoltageswingPARAMETERTESTCONDITIONSLF411ALF411UNITMINTYPMAXMINTYPMAXVOSInputOffsetVoltageRS=10kΩ,TA=25℃

0.30.5

0.82.0mVΔVOS/ΔTAverageTCofInputOffsetVoltageRS=10kΩ

7

7

μV/℃IOSInputOffsetCurrentVS=±15V(2)(3)Tj=25℃

25100

25100pATj=70℃

2

2nATj=125℃

25

25nAIBInputBiasCurrentVS=±15V(2)(3)Tj=25℃

50200

50200pATj=70℃

4

4nATj=125℃

50

50nARINInputResistanceTj=25℃

1012

1012

ΩAVOLLargeSignalVoltageGainVS=±15V,VO=±10V,RL=2k,TA=25℃50200

25200

V/mVOverTemperature25200

15200

V/mVVOOutputVoltageSwingVS=±15V,RL=2k±12±13.5

±12±13.5

VVCMInputCommon-ModeVoltageRange

±16+19.5

±11+14.5

V

-16.5

-11.5

VCMRRCommon-ModeRejectionRatioRS≤10k80100

70100

dBPSRRSupplyVoltageRejectionRatioSee(4)80100

70100

dBISSupplyCurrent

1.82.8

1.83.4mAOp-AmpACCharacteristicsSlewrateGain-bandwidthproduct(GBW)InputnoisevoltageandcurrentTotalharmonicdistortion(THD)PARAMETER(1)(2)TESTCONDITIONSLF411ALF411UNITMINTYPMAXMINTYPMAXSRSlewRateVS=±15V,TA=25℃1015

815

V/μsGBWGain-BandwidthProductVS=±15V,TA=25℃34

2.74

MHzenEquivalentInputNoiseVoltageTA=25℃,RS=100Ω,f=1kHz

25

25

nV/√HzinEquivalentInputNoiseCurrentTA=25℃,f=1kHz

0.01

0.01

pA/√HzTHDTotalHarmonicDistortionAV=+10,RL=10k,VO=20Vp-p,BW=20Hz-20kHz

<0.02%

<0.02%

VoltageReferencesProvidestable,accuratevoltagesCriticalforADCandDACaccuracyAccuracydirectlylimitssystemresolutionTypesofVoltageReferencesSeries(three-terminal)referencesShunt(two-terminal)referencesTrade-offsinaccuracy,current,andflexibilityDiode-BasedReferencesForward-biaseddiodereferencesZener/avalanchediodereferencesSimplebutlimitedaccuracyandnoiseperformanceBandgapVoltageReferencesBasedonsiliconbandgap(~1.205V)ExcellenttemperaturestabilityOperatesatlowsupplyvoltagesBrokawBandgapCellUsesΔVBEandVBEsummationTemperaturecoefficientminimizedFoundationofmodernprecisionreferencesAnalogFiltersFrequency-selectivesignalprocessingSuppressinterferenceandnoiseEssentialincommunicationsystemsFilterTypesLow-passfilter(LPF)High-passfilter(HPF)Band-passfilter(BPF)Band-stopfilter(BSF)FilterSpecificationsPassbandripple(Amax)Stopbandattenuation(Amin)CutofffrequenciesTransitionbandandselectivityDataConvertersOverviewInterfacebetweenanaloganddigitaldomainsDigital-to-AnalogConverters(DACs)Analog-to-DigitalConverters(ADCs)Digital-to-AnalogConverters(DACs)ConvertdigitalcodesintoanalogvoltagesorcurrentsResolutiondefinedbynumberofbitsAccuracydependsonreferenceandmatchingR-2RLadderDACUsesonlyRand2RresistorsExcellentmatchingpropertiesWidelyusedinICDACsModernDACFeaturesIntegratedvoltagereferenceOutputbufferamplifiersSerialandparalleldigitalinterfacesAnalog-to-DigitalConverters(ADCs)QuantizeanalogsignalsintodigitalcodesResolutionandsamplingratedefineperformanceKeyelementindataacquisitionsystemsADCFunctionalBlocksSample-and-holdcircuitQuantizerandencoderReferencevoltagesourceADCClockingandControlSamplingclockrequirementsvarybyarchitectureEnd-of-conversion(EOC)anddata-readysignalsCarefultimingrequiredforreliableoperationTrendsinDataConvertersLowersupplyvoltages