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SEMICONDUCTORTECHNICALDATA1REV2Motorola,Inc.19971/97 TheMC1648requiresanexternalparalleltankcircuitconsistingoftheinductor(L)andcapacitor(C).ForMaximumPerformanceQL≥100atFrequencyofOperation.Avaractordiodemaybeincorporatedintothetankcircuittoprovideavoltagevariableinputfortheoscillator(VCO).TheMC1648wasdesignedforuseintheMotorolaPhase–LockedLoopshowninFigure9.Thisdevicemayalsobeusedinmanyotherapplicationsrequiringafixedorvariablefrequencyclocksourceofhighspectralpurity.(SeeFigure2)TheMC1648maybeoperatedfroma+5.0Vdcsupplyora–5.2Vdcsupply,dependinguponsystemrequirements.NOTE:TheMC1648isNOTuseableasacrystaloscillator.Pinout:14–LeadPackage(TopView)1314121110982134567VCCNCTANKNCBIASNCVEEVCCNCOUTNCAGCNCVEEPinassignmentisforDual–in–LinePackage.ForPLCCpinassignment,seetheMC1648Non–StandardPinConversionTablebelow.MC1648NON–STANDARDPINCONVERSIONDATAPackageTANKVCCVCCOUTAGCVEEVEEBIAS8D1234567814L,P1214135781020FN1820248101214*NOTE–Allunusedpinsarenotconnected.SupplyVoltageGNDPinsSupplyPins+5.0Vdc7,81,14–5.2Vdc1,147,85AGCLOGICDIAGRAM3TANK12BIASPOINT10OUTPUT•InputCapacitance=6.0pF(TYP)•MaximumSeriesResistanceforL(ExternalInductance)=50Ω(TYP)•PowerDissipation=150mW(TYP)/Pkg(+5.0VdcSupply)•MaximumOutputFrequency=225MHz(TYP)VCC1=Pin1VCC2=Pin14VEE=Pin7 VOLTAGECONTROLLEDOSCILLATORFNSUFFIX20–LEADPLCCPACKAGECASE775–02LSUFFIX14–LEADCERAMICPACKAGECASE632–08PSUFFIX14–LEADPLASTICPACKAGECASE646–06DSUFFIX8–PINPLASTICSOICPACKAGECASE751–05NotRecommendedforNewDesignsMC1648MOTOROLAHIPERCOMMBR1334—Rev42Figure1.CircuitSchematic5AGC8VEE12TANK10BIASPOINT7VEE1VCC214VCC11Q4Q3Q2Q1Q5D1Q8Q7Q6Q9Q10Q11D23OUTPUTTESTVOLTAGE/CURRENTVALUES@TestTemperature(Volts)mAdcTemperatureVIHmaxVILminVCCILMC1648–30°C+2.0+1.5+5.0–5.0+25°C+1.85+1.35+5.0–5.0+85°C+1.7+1.2+5.0–5.0Note:SOIC“D”packageguaranteed–30°Cto+70°ConlyELECTRICALCHARACTERISTICS(SupplyVoltage=+5.0V)–30°C+25°C+85°CSymbolCharacteristicMinMaxMinMaxMinMaxUnitConditionIEPowerSupplyDrainCurrent–––41––mAdcInputsandoutputsopenVOHLogic“1”OutputVoltage3.9554.1854.044.254.114.36VdcVILmintoPin12,IL@Pin3VOLLogic“0”OutputVoltage3.163.43.23.433.223.475VdcVIHmaxtoPin12,IL@Pin3VBIAS1BiasVoltage1.61.91.451.751.31.6VdcVILmintoPin12MinTypMaxMinTypMaxMinTypMaxUnitConditionVP–PPeak–to–PeakTankVoltage––––400––––mVSeeFigure3VdcOutputDutyCycle––––50––––%fmax2OscillationFrequency–225–200225––225–MHz1.Thismeasurementguaranteesthedcpotentialatthebiaspointforpurposesofincorporatingavaractortuningdiodeatthispoint.2.FrequencyvariationovertemperatureisadirectfunctionoftheΔC/ΔTemperatureandΔL/ΔTemperature.MC1648HIPERCOMMBR1334—Rev43MOTOROLAFigure2.SpectralPurityofSignalOutputfor200MHzTestingB.W.=10kHzCenterFrequency=100MHzScanWidth=50kHz/divVerticalScale=10dB/div0.1μF1200*CL101250.1μF3SIGNALUNDERTEST10μF0.1μF114L=40nHC=10pF+5.0VdcL:MicroMetaltorroid#T20–22,8turns#30EnameledCopperwire.C=3.0–35pF*The1200ohmresistorandthescopeterminationimpedanceconstitutea25:1attenuatorprobe.CoaxshallbeCT–075–50orequivalent.TESTVOLTAGE/CURRENTVALUES@TestTemperature(Volts)mAdcTemperatureVIHmaxVILminVEEILMC1648–30°C–3.2–3.7–5.2–5.0+25°C–3.35–3.85–5.2–5.0+85°C–3.5–4.0–5.2–5.0Note:SOIC“D”packageguaranteed–30°Cto+70°ConlyELECTRICALCHARACTERISTICS(SupplyVoltage=–5.2V)–30°C+25°C+85°CSymbolCharacteristicMinMaxMinMaxMinMaxUnitConditionIEPowerSupplyDrainCurrent–––41––mAdcInputsandoutputsopenVOHLogic“1”OutputVoltage–1.045–0.815–0.96–0.75–0.89–0.64VdcVILmintoPin12,IL@Pin3VOLLogic“0”OutputVoltage–1.89–1.65–1.85–1.62–1.83–1.575VdcVIHmaxtoPin12,IL@Pin3VBIAS1BiasVoltage–3.6–3.3–3.75–3.45–3.9–3.6VdcVILmintoPin12MinTypMaxMinTypMaxMinTypMaxUnitConditionVP–PPeak–to–PeakTankVoltage––––400––––mVSeeFigure3VdcOutputDutyCycle––––50––––%fmax2OscillationFrequency–225–200225––225–MHz1.Thismeasurementguaranteesthedcpotentialatthebiaspointforpurposesofincorporatingavaractortuningdiodeatthispoint.2.FrequencyvariationovertemperatureisadirectfunctionoftheΔC/ΔTemperatureandΔL/ΔTemperature.MC1648MOTOROLAHIPERCOMMBR1334—Rev44Figure3.TestCircuitandWaveforms0.1μF1200CL10120.1μF3*VCC*****5VEEQL≥100*Usehighimpedanceprobe(1.0Megohmmustbeused).**The1200ohmresistorandthescopeterminationimpedanceconstitutea25:1attenuatorprobe.CoaxshallbeCT–070–50orequivalent.***Bypassonlythatsupplyoppositeground.50%tatbVP–PPRF=1.0MHzDutyCycle(Vdc)–tatb781140.1μF0.1μF***OPERATINGCHARACTERISTICSFigure1illustratesthecircuitschematicfortheMC1648.TheoscillatorincorporatespositivefeedbackbycouplingthebaseoftransistorQ6tothecollectorofQ7.Anautomaticgaincontrol(AGC)isincorporatedtolimitthecurrentthroughtheemitter–coupledpairoftransistors(Q7andQ6)andallowoptimumfrequencyresponseoftheoscillator.InordertomaintainthehighQoftheoscillator,andprovidehighspectralpurityattheoutput,transistorQ4isusedtotranslatetheoscillatorsignaltotheoutputdifferentialpairQ2andQ3.Q2andQ3,inconjunctionwithoutputtransistorQ1,providesahighlybufferedoutputwhichproducesasquarewave.TransistorsQ9andQ11providethebiasdrivefortheoscillatorandoutputbuffer.Figure2indicatesthehighspectralp