TheAD8260includesahighcurrentdriver,usableasatransmitter,andalownoise,digitallyprogrammablevariablegainamplifier(DGA),useableasareceiver,combinedina5mm×5mm,32-leadchipscalepackage.
Thereceiversectionconsistsofasingle-endedinputpreamplifier,andlinear-in-dB,differential-outputVGA.Usableatdcandfrequenciesto80MHz;the–3dBbandwidthis180MHz.Thedriver-amplifierdelivers±300mA,wellsuitedfordrivinglowimpedanceloads,evenwhenconnectedtoa3.3Vsupply.
TheAD8260DGAisidealfortrimapplicationsandhasagainspanof30dB,in3dBsteps.Excellentbandwidthuniformityismaintainedacrosstheentirefrequencyrange.TheDGA’slowoutput-referrednoiseisadvantageousindrivinghighspeedADCs.ThedifferentialoutputfacilitatestheinterfacetomodernlowvoltagehighspeedADCs.
Single-supplyanddual-supplyoperationmakesthepartversatileandenablesgaincontrolofnegative-goingpulses,suchasgeneratedbyphotodiodesorphoto-multipliertubes,aswellasprocessingband-passsignalsonasinglesupply.Formaximumdynamicrange,itisessentialthatthepartbeac-coupledwhenoperatingonasinglesupply.
TheAD8260preamplifier(PrA)isuserconfigurablewithexternalresistorsforgainsgreaterthan6dB;aswithanyhighfrequencyopamp,thegainisinvertingornoninverting.TheDGAischaracterizedwithanoninvertingPrAgainof2×.Theattenuatorhasarangeof30dBandtheoutputamplifierhasagainof8×(18.06dB).Thelowestnoninvertinggainrangeis−6dBto+24dBandshiftsupwithincreasedPrAgain.Thegainiscontrolledviaaparallelport(PinGNS0toPinGNS3)with10gainstepsof3dBpercode.Foranynonusedcode,thepreamplifierandDGAaredisabled.
TheAD8260canoperatewithsingleordualsuppliesfrom3.3Vto±5V.Aninternalbuffernormallyprovidesasplitsupplyreferenceforsingle-supplyoperation;anexternalreferencecanalsobeusedwhentheVMIDbufferisshutdown.
Theoperatingtemperaturerangeis−40°Cto+105°C.TheAD8260isavailableina32-leadLFCSP.