電子專業(yè)英語(yǔ)Lesson 8 Clock Sources

Unit3ElectronicSystemComponentsLesson8ClockSources《電子信息工程專業(yè)英語(yǔ)教程》任治剛主編電子工業(yè)出版社

5/13/20241Lesson8ClockSourcesBackgroundsTexttour

LanguageinuseVocabularyStructureReading/writingtechniques5/13/20242TerminologyOscillatorTCXO,PLL,VCODetectorBackgrounds5/13/20243Terminology

5/13/20244Oscillator振蕩器Resonant諧振的SeriesResonant串聯(lián)諧振ParallelResonant并聯(lián)諧振Resonatingfrequency諧振頻率Oscillator5/13/20245TCXO:TemperatureCompensatedCrystalOscillator 溫度補(bǔ)償晶體振蕩器PLL:PhaseLockedLoop 鎖相環(huán)VCO:VoltageControlledOscillator 壓控振蕩器TCXO,PLL,VCO5/13/20246detectorn.檢測(cè)器，檢波器，探測(cè)元件phasedetectorn.鑒相器,相位檢測(cè)器frequencydetectorn.鑒頻器,頻率檢測(cè)器Detector5/13/20247OutlineClockDevicesCrystals,CrystalOscillators,CompensatedOscillators,VoltageControlledOscillator,FrequencySynthesizers,ClockBuffersClockParametersClockJitter,Skew,Tolerance/Accuracy,Stability,Aging,Slew,DutyCycleTexttour5/13/20248Abasicpiezoelectricquartzcrystal

TwokindsofcrystalsSeriesResonantParallelResonantClockDevices

Crystals5/13/20249Anoscillatorwiththecrystalasthefeedbackelement

Providesthemostaccurateandstableoutputfrequency.Thepreferredclocksourceinmosthigh-speeddigitalsystemsrequiringclocks.ClockDevices

CrystalOscillators5/13/202410TrytoadjustthevariationinfrequencyduetotemperatureandvoltageTemperatureCompensatingOscillators(TCXO)

ClockDevices

CompensatedOscillators5/13/202411Theoutputof

VCOiscontrolledbyavoltagecontrolinputpin.

ClockDevices

VoltageControlledOscillator5/13/202412UseoneormorePLLtogenerateonetomanydifferentfrequenciesontheiroutputs,fromoneormorereferencesources.APLLhastwoinputsareferenceinputafeedbackinput.APLLcorrectsfrequencyintwowaysfrequencycorrectionPhasecorrectionClockDevices

FrequencySynthesizers5/13/202413Figure3.4.BlockDiagramofaPhaseLockedLoopClockDevices

FrequencySynthesizers5/13/202414Adeviceinwhichtheoutputwaveformdirectlyfollowstheinputwaveform.HaveapropagationdelaySkewwillexistontheoutputs

ClockDevices

ClockBuffers5/13/202415Thedeviationsinaclock’soutputtransitionsfromtheiridealpositions.Cycle-cyclejitterPeriodjitterLong-termjitterCausesofjitterPowersupplynoiseTheinternalPLLofthesynthesizerRandommechanicalnoisefromvibrationsofthecrystalRandomthermalnoisefromcrystal,oranyotherresonatingdevice.ClockParameters

ClockJitter5/13/202416Thevariationinarrivaltimeoftwosignalsspecifiedtoarriveatthesametime

ClockDriverSkew(IntrinsicSkew)BoardDesignSkew(Extrinsicskew)ClockParameters

Skew5/13/202417Ameasureofhowclosethepartoperatestothespecified(nominal)frequency,typicallyreferencedatambienttemperature(25oC+/-5oC).ClockParameters

Tolerance/Accuracy5/13/202418Aparameterusuallyassociatedwithcrystalsandoscillators.ClockParameters

Stability5/13/202419Thesystematicchangeinfrequencyovertimeduetointernalchangesincrystal/oscillator.ClockParameters

Aging5/13/202420Therateofchangeofvoltageorfrequency

ClockParameters

Slew5/13/202421Theratiooftheoutputhightimetothetotalcycletime.ClockParameters

DutyCycle5/13/202422VocabularyIncrement,propagation,deviation,transition,Intrinsic,extrinsic,nominalStructureReading/writingtechniquesLanguageinuse5/13/202423Vocabulary5/13/202424IncrementindictionaryTheprocessofincreasinginnumber,size,quantity,orextent. 增加Somethingaddedorgained: 增量Aslight,oftenbarelyperceptibleaugmentation. 微小增長(zhǎng)Oneofaseriesofregularadditionsorcontributions: 累加Asmallpositiveornegativechangeinthevalueofavariable. 變量增量5/13/202425IncrementintextTheResolutionwilldetermineinwhatsizeincrementsthefrequencycanchange.精度決定了頻率改變的增量。

5/13/202426Incrementinuseangleincrement角增量annualincrement年增量averageincrement平均增量frequencyincrement頻率增量logarithmicincrement對(duì)數(shù)增量5/13/202427PropagationindictionaryMultiplicationorincrease,asbynaturalreproduction. 繁殖Theprocessofspreadingtoalargerareaorgreaternumber;dissemination. 蔓延；散發(fā)Theactorprocessofpropagating,especiallytheprocessbywhichadisturbance,suchasthemotionofelectromagneticorsoundwaves,istransmittedthroughamediumsuchasairorwater. 傳播5/13/202428PropagationintextAClockBufferisadeviceinwhichtheoutputwaveformdirectlyfollowstheinputwaveform.Theinputwaveformpropagatesthroughthedeviceandisredrivenbytheoutputbuffers.Hence,suchdeviceshaveapropagationdelayassociatedwiththem.Inaddition,duetothedifferencesbetweenthepropagationdelaythroughthedeviceoneachinput-outputpath,skewwillexistontheoutputs.時(shí)鐘緩沖器是一種輸出波形直接跟隨輸入波形的器件。輸入波形通過該器件并被輸出緩沖器重新驅(qū)動(dòng)。因此，該類器件存在傳播延遲。此外，由于在每個(gè)輸入-輸出通道間存在傳播延遲的差別，輸出端將出現(xiàn)相位抖動(dòng)。5/13/202429Propagationinusebeyond-the-horizonpropagation超越地平線傳播,超視距傳播carrypropagation進(jìn)位傳送earth-layerpropagation地層傳播errorpropagation誤差傳播forward-scatterpropagation前向散射傳播freespacepropagation自由空間傳播5/13/202430Propagationinusegroundwavepropagation地波傳播high-frequencypropagation高頻傳播microwavepropagation微波傳播multipathpropagation多徑傳播radiopropagation無線電波傳播ultrasonicpropagation超聲波傳播5/13/202431DeviationindictionaryTheactofdeviatingorturningaside. 背離，偏離Anabnormality;adeparture: 反常；偏移：Deviantbehaviororattitudes. 不正常的行為或態(tài)度Thedifference,especiallytheabsolutedifference,betweenonenumberinasetandthemeanoftheset. 偏差5/13/202432DeviationintextJittercanbedefinedasthedeviationsinaclock’soutputtransitionsfromtheiridealpositions.Thedeviationcaneitherbeleadingorlaggingtheidealposition.抖動(dòng)被定義為時(shí)鐘輸出的狀態(tài)轉(zhuǎn)換位置偏離了理想位置。這種偏離可能超前于理想位置，也可能滯后于理想位置。5/13/202433absolutedeviation絕對(duì)差randomdeviation隨機(jī)偏差secondorderdeviation二階方差systemdeviation系統(tǒng)偏差Deviationinuse5/13/202434Deviationinuse

deviationaberrationdivergence

Thecentralmeaningsharedbythesenounsisthedeparturefromwhatisprescribedorexpected.toleratesnodeviationfromtherules;regrettedtheaberrationsofherearlylife;thedivergenceoftwocultures.5/13/202435TransitionindictionaryTheswitchingfromonestate(e.g.,positivevoltage)toanother(negative)inaserialtransmission.Achangefromonesignificantconditiontoanotherinatelegraphoradatasignal.5/13/202436TransitionintextPeriodjitter,alsocalledshort-termjitter,isachangeinaclock’soutputtransitionfromitsidealpositionoverconsecutiveclockedges.周期內(nèi)抖動(dòng)也稱為短期抖動(dòng)。它是指在相繼時(shí)鐘邊沿的范圍內(nèi)時(shí)鐘輸出狀態(tài)轉(zhuǎn)換位置偏離理想位置。5/13/202437Transitioninuseblack-to-whitetransition黑白過渡coaxial-to-waveguidetransition同軸線-波導(dǎo)管過渡environmentaltransition環(huán)境變遷flip-floptransition觸發(fā)器狀態(tài)轉(zhuǎn)換5/13/202438Intrinsic,extrinsicindictionaryIntrinsic：

Oforrelatingtotheessentialnatureofathing;inherent. 本質(zhì)的；固有的Theintrinsicvalueofacoinisthevalueofthemetalitismadeof.Extrinsic：Notforminganessentialorinherentpartofathing;extraneous. 非本質(zhì)的，無關(guān)系的That'ssomethingextrinsictothesubject.Originatingfromtheoutside;external. 外來的；外部的5/13/202439Intrinsic,extrinsicintextClockDriverSkew(IntrinsicSkew)istheamountofskewcausedbytheclockdriveritself.時(shí)鐘驅(qū)動(dòng)器相位偏移（內(nèi)部相位偏移）是由時(shí)鐘驅(qū)動(dòng)器引起的相位偏移量。BoardDesignSkew(Extrinsicskew)istheamountofskewcausedbyboardlayoutissuessuchas:電路板設(shè)計(jì)相位偏移（外部相位偏移）是由下列電路板布線問題造成的相位偏移量：5/13/202440NominalindictionaryAssignedtoorbearingaperson'sname提名的，記名的Existing