ACCurrentProbes CT1CT2CT6Datasheet Applications DataStorageRead ChannelDesign Silicon Characterization High-frequency Analog Design ESD Testing Signal Injection Differential Current Measurements Single-shotLowRep-ratePulseMeasurements PropagationDelay Measurement CT6CurrentProbe TheCT6isthenewestadditiontotheTektronixportfolioofhigh-frequency current probes. It is designed to meet the needs of high-speed circuit design and test applications which require ultra-high bandwidth, low inductance, and extremely small form factor. The CT6 provides up to 2GHzbandwidthwhenusedwithhigh-bandwidthoscilloscopessuchas theTektronixTDS694C,TDS794D,andTDS7000Seriesoscilloscopesor withothercompatible50 inputmeasuringinstruments. Lowinductance (<3nH)assuresthattheloadingeffectoftheCT6onthecircuit-under-test willbenegligible,whichisespeciallyimportantfortoday slow-amplitude, high-speedcircuitdesignssuchasdiskdriveread/writepreampliers. The probeisa closed-circuit designwhichwillaccept uninsulatedwiresized upto20gauge. ThisproductisexemptfromCEmarkbyvirtueofits30V voltage limit. CT6. Current Probe CT1/CT2CurrentProbes The CT1 and CT2 Current Probes are designed for permanent or Features&Benets semi-permanent in-circuit installation. Each probe consistsof a current transformerandaninterconnectingcable. Thecurrenttransformershave High Bandwidth asmallholethroughwhichacurrentcarryingconductorispassedduring Ultra-low Inductance circuit assembly. Very Small Form Factor TheP6041ProbeCableprovidestheconnectionbetweentheCT1andCT2 CurrentTransformersandaBNC oscilloscopeinput. A 50 termination CharacterizeCurrentWaveformsupto<200psRiseTimes isrequired to terminatethecable when connectedto a high-impedance VeryLowLoadingofCircuitUnder Test (1M )oscilloscopeinput. Oneprobecablecanbeusedtomonitorseveral FitsIntoDense,Closely-spacedCircuitDesigns currenttransformersthathavebeenwiredintoacircuit.Datasheet conjunction with compatible high-bandwidth oscilloscopes and other instrumentstoobserveand/orrecordhigh-frequencycurrentwaveforms. TheCT1, CT2, and CT6normallyoperatedirectlyinto50 scopesand other measuring device inputs. The CT1 or CT2 canbeusedwith1M input systems use the P6041 probecableandterminatetheoutputwitha50 feed-throughtermination (see OptionalAccessories). In all cases, the CT1, CT2, and CT6 must work into 50 s to obtain specied performance and sensitivity. TypicalMeasurementApplications DifferentialCurrentMeasurements Most true-differential voltage ampliers have a maximum bandwidth of about 100 MHz. The CT1 or CT6 can make differential current measurementsto 1 GHz and 2GHz, respectively, by passing two wires carryingopposingcurrentsthroughthesamecore. Thedisplayedresultis CT1/CT2. CurrentProbeswithP6041BNCProbeCable. thedifferencecurrent. TheCT2canperformthesamefunctionto200MHz. In all cases, Derating with Frequency and Amp-second Product MiniatureConstruction (Current-time Product) guidelines should not be exceeded. (See TheCT1andCT2detachablecabledesignenablesoneormoreprobesto Characteristics.) belocatedoncircuitboardsorinotherlimitedspaceareas. Single-shotandLowRep-ratePulseMeasurements The CT6 offers the smallest form factor available, for measurement on ThesecommonmeasurementsareeasytomakewiththeCT1,CT2,orCT6 ever-shrinkingcircuitboardsandcomponents. Itisdesignedfortemporary providedthatyoursignal tswithintheMaxPulseCurrentandAmp-second installationanddoesnot incorporateremovable cables, astheCT1 and Product(Current-timeProduct)guidelinesfor the specic current probe CT2 do. characteristics. ExtendibleProbeLength Forexample,theCT2isratedat36Apeak,withanAmp-secondProduct -6 of5010 seconds(50Amp-microseconds),thereforetheCT2cansafely Specied rise time and bandwidth are obtained when using the probe handlea36Apeakpulsewithamaximumwidthof1.39microsecondsor cablesprovided: TheP6041cableusedwiththeCT1andCT2is42inches loweramplitudepulsesforlongerpulsewidths. TheCT1, CT2, andCT6 nominal. Ifadditional length isrequired, the cables can be extendedby allhavelow-frequencyroll-offcharacteristics. Low-frequencdroowill usinghigh-quality50 cableandsuitableinterfaceconnectors. (Alsosee exhibititselfwhenthepulsewidthapproachestheL/Rtimeconstantofthe SpecialProbeCables,OptionalAccessories.) Longcablesmaydegrade specic transformer. high-frequency response. PropagationDelayMeasurements HighSensitivity Two CT1 or CT2Current Transformers with matching probe cablescan The CT1 and CT6 provide an output of 5 mV for each milliamp of input be used to measure propagation delay (transit time) between the input currentwhenterminatedin50 . TheCT2provides1mVpermilliampwhen and output currents of high-frequency devices. The probe outputs are terminated in 50 . connectedtotheinputsofdual-channelreal-timeorsamplingscopes. TypicalSystems VericationofanyProbe/Cable/ScopeSystemmismatchcanbeobtained TheCT1,CT2,andCT6high-frequencycurrenttransformersaredynamic bypassingthesamesignalcurrentthroughbothprobesandobservingtotal (i.e., non-DC) current measuring devices. They are typically used in system delaydifference, if any. 2 www.tektronix.com