User's Guide SBAU307A–December2017–RevisedMarch2018 Precision Labs SAR ADC EVM This user's guide describes the characteristics and use of the Precision Labs SAR ADC EVM. The evaluation module (EVM) is designed to as a companion to the TI Precision Labs-ADCs training series and is referred to as the PLABS-SAR-EVM-PDK throughout this document. This hardware allows engineers to perform experiments on general data converter topics such as ADC input drive, reference drive, amplifier selection, power consumption, and aliasing. This user's guide provides information regarding the operation and theory behind the sub-circuits on the EVM, as well as an overview of the requiredsoftware. USB Cable PLABS-SAR-EVM PHI-EVM (Digital Controler) SMA Cable USB Cable PSI-EVM (Signal Source) 10 Coupon Cards Different Amplifier Configurations Figure1.TypicalConnectionsforthePLABS-SAR-EVM-PDK SBAU307A–December2017–RevisedMarch2018 PrecisionLabsSARADCEVM 1 SubmitDocumentationFeedback Copyright©2017–2018,TexasInstrumentsIncorporated www.ti.com ThefollowingrelateddocumentsareavailablethroughtheTexasInstrumentswebsite. Table1.RelatedDocumentation Device LiteratureNumber ADS1220 SBAS501 ADS7042 SBAS608 ADS8860 SBAS569 INA326 SBOS222 LPV811 SNOSD33 OPA316 SBOS703 OPA320 SBOS513 OPA333 SBOS351 REF5050 SBOS410 REF6050 SBOS708 TLV313 SBOS753 Contents 1 Introduction................................................................................................................... 4 2 EVMInitialSetup ............................................................................................................ 4 3 Plug-InAmplifierCouponBoards ....................................................................................... 15 4 EVMGraphicalUserInterface(GUI)SoftwareInstallation........................................................... 17 5 BoardLayout................................................................................................................ 29 6 SchematicandBillofMaterials........................................................................................... 33 ListofFigures 1 TypicalConnectionsforthePLABS-SAR-EVM-PDK................................................................... 1 2 OverviewofFeaturesonCH1andCH2.................................................................................. 5 3 AmplifierandADCInput(CH1andCH2)................................................................................. 6 4 VoltageReferenceandJumper-SelectedVoltageDivider(CH1andCH2).......................................... 6 5 JumperPositionforaDCInputof0.1VonCH1andCH2............................................................ 7 6 JumperPositionforanACInputonCH1andCH2..................................................................... 7 7 PowerSubsection(CH1andCH2)........................................................................................ 8 8 ConnectiontothePHIControllerandEEPROM........................................................................ 9 9 OverviewofFeaturesonCH3............................................................................................ 10 10 AmplifierandADCInput(CH3)........................................................................................... 11 11 INACurrentMonitor(CH3)................................................................................................ 12 12 Power,ShuntResistors,andRangeSelectionforCH3 .............................................................. 13 13 DCorACInput(CH3)..................................................................................................... 14 14 CouponCardLayout....................................................................................................... 15 15 InstallingaCouponCard.................................................................................................. 15 16 PLABSToolkitLink ........................................................................................................ 17 17 ApplicationsAgreement .................................................................................................. 18 18 PlabsToolkitDialogBox.................................................................................................. 19 19 Software Installation....................................................................................................... 20 20 PlabsToolkitPrompt ...................................................................................................... 21 21 DefaultPLABS-SAR-EVMGUIDisplay ................................................................................ 21 22 PSIControls:UnconnectedPSIHardware............................................................................. 22 23 PSIControls:ReadytoGenerateanInputSignal .................................................................... 23 24 TimeDomainDisplay...................................................................................................... 24 25 SpectralAnalysisDisplay................................................................................................. 25 2 PrecisionLabsSARADCEVM SBAU307A–December2017–RevisedMarch2018 SubmitDocumentationFeedback Copyright©2017–2018,TexasInstrumentsIncorporated www.ti.com 26 Histogram Analysis......................................................................................................... 26 27 RegisterMapConfiguration .............................................................................................. 27 28 PowerScalingResults..................................................................................................... 28 29 PCBTopLayer............................................................................................................. 29 30 Bottom Layer................................................................................................................ 30 31 Ground Layer............................................................................................................... 31 32 Power Layer ................................................................................................................ 32 33 Page1:Channel1......................................................................................................... 33 34 Page2:Channel2......................................................................................................... 34 35 Page3:Channel1and2Power......................................................................................... 35 36 Page4:Channel3......................................................................................................... 36 37 Page5:Channel3Current-ShuntAmplifiersandADC............................................................... 37 38 Page6:Channel3LDOandShuntResistors ......................................................................... 38 39 Page7:Hardware.......................................................................................................... 39 40 OPA320GoodFilter1..................................................................................................... 40 41 OPA320BadFilter......................................................................................................... 40 42 OPA333LowBandwidth.................................................................................................. 40 43 OPA316Crossover........................................................................................................ 41 44 OPA320Noise1 ........................................................................................................... 41 45 Sallen-Key Filter............................................................................................................ 41 46 TLV313LowPower........................................................................................................ 42 47 LPV811Nanopower ....................................................................................................... 42 48 OPA320Noise2 ........................................................................................................... 42 49 OPA320GoodFilter2..................................................................................................... 43 ListofTables 1 RelatedDocumentation..................................................................................................... 2 2 HardwareIncludedinthePLABS-SAR-EVM-PDK...................................................................... 4 3 CouponCardDescriptions................................................................................................ 16 4 BillofMaterialsfortheSAR-ADC-EVMMotherboard................................................................. 44 5 BillofMaterialsfortheSAR-ADC-EVMCouponBoards.............................................................. 47 Trademarks Alltrademarksaretheproperty oftheirrespectiveowners. SBAU307A–December2017–RevisedMarch2018 PrecisionLabsSARADCEVM 3 SubmitDocumentationFeedback Copyright©2017–2018,TexasInstrumentsIncorporated Introduction www.ti.com 1 Introduction ThePLABS-SAR-EVM-PDK isanevaluationmodule(EVM)kitcontainingasignalgenerator,ananalog- to-digital converter(ADC)board,plug-inamplifiercards,andadigitalcontroller.Thiskitisintended to be usedinconjunctionwiththeTIPrecisionLabs-ADCstraining series. 1.1 Features ThePLABS-SAR-EVM-PDK includesthefollowingfeatures: • Threesuccessive-approximationregister(SAR)ADCsub-circuitscomprisedoftheADS8860 and REF5050,theADS8860andREF6050,andtheADS7042. • Tenplug-inDIPadapterboardscontainingdifferent amplifierconfigurations. • Jumper-selectableDCinputvoltages(0.1V,1V,2V,and5V). • Jumper-selectableinput(DCorAC). • Jumper-selectablecurrentmeasurementrangesfor theopampandADC. • PoweredoverasingleUSBcable. 2 EVM Initial Setup TypicalconnectionforthePLABS-SAR-EVM-PDKaregiveninFigure1.Theincludedhardwareforthis EVM kitisgiveninTable2. 2.1 Included Hardware Table2liststheincludedhardwarewiththisEVM. Table2.HardwareIncludedinthePLABS-SAR-EVM-PDK Item Quantity Description ThisPCBcontainsthreedifferentADCconfigurationsandallowsdifferentamplifier PLABS-SAR-EVM 1 driverstobetestedusingplug-inamplifiercouponboards.ThePCBisintendedasa companiontoTIPrecisionLabs-ADCstrainingseriesforhands-onexperiments. ThisPCBisthedigitalcontrollerusedtocommunicatewiththeADCsonthePLABS- PHI-EVM 1 SAR-EVM-PDK. ThisPCBistheistheprecisionsignalsourceusedtogeneratetestsignalsfor PSI-EVM 1 precisionlabsexperiments. USBcable 2 UsedtocommunicatewiththePHI-EVMandthePSI-EVM. SMAcable 1 Usedtoconnectthesignalgenerator(PHI-EVM)tothePLABS-SAR-EVM-PDK. OPA320goodfilter 1 DemonstratesperformanceontheADS8860. OPA320badfilter 1 Demonstratespoorcomponentselection. OPA333lowbandwidth 1 Demonstratespoorcomponentselection. OPA316crossover 1 Demonstratescrossoverdistortion. OPA320noise1 1 Demonstratesnoisemeasurement. Sallenkeyfilter 1 Demonstratesanantialiasingfilter. TLV313lowpower 1 Demonstrateslowpoweramplifierdriverperformance. LPV811nanopower 1 Demonstrateslowpoweramplifierdriverperformance. OPA320noise2 1 Demonstratesnoisemeasurement. OPA320goodfilter2 1 DemonstratesperformanceontheADS7042. 4 PrecisionLabsSARADCEVM SBAU307A–December2017–RevisedMarch2018 SubmitDocumentationFeedback Copyright©2017–2018,TexasInstrumentsIncorporated www.ti.com EVMInitialSetup 2.2 Channel 1 and 2 Operation Figure2 showsthefeaturesonchannel1andchannel2(CH1andCH2,respectively)ofthePLABS-SAR- EVM.Thedesignofthesetwochannelsisverysimilar.Theonlydifferenceisthat channel1usesthe REF5050andchannel2usestheREF6050.TheREF6050containsawidebandwidthbuffer andthus showsbetterperformancethantheREF5050.Thegoalistoshowtheimpactthat referencebufferinghas onperformance.BothchannelshaveanSubMiniatureversionA(SMA)input connectorfor theACinput andbothchannelsshareaprecisionDCsource. ThethreeLEDindicatorsaresharedbetweenthe two channelsandareagoodquickchecktodetermineiftheboardispowered.Eachchannelhasit'sown connectortothePHIdigitalcontroller,andthesoftwareusedfor eachchannelisidentical. Test points for key Connector to digital signals and supplies controller PHI for CH1 Texas Instruments GND Precision Labs PLABS-SAR-EVM AC input CH1 VREF5050 PWR_3.3V PWR_5.2V AVDDDVDD Input SAR ADS 5.2V IN- ADS8860 VIN IN+ S2 S1 RSH GND GND VNI COPM REG Input CH1 GND GND CSH CDAC PHI_CH1 S1 GND REF5050 GND AC or DC DAQ Channel 1 Led power input selection AC_IN DC_IN indicators 4.9V 3.5V PWR_5.2V PWR_3.3V PWR_PHI DC input for 2.5V 0.1V SDI CH1 and CH2 AVDDDVDD CVST SAR ADS SCLK 5.2V IN- ADS8860 S2 SDO VIN IN+ VI S1 RSH COM REG GND GND N CSH P Input CH2 GND GND CDAC Input AC input CH1 REF6050 S2 PHI_CH2 GND GND DAQ Channel 2 Socket for amplifier Connector to digital controller PHI for CH2 Figure2.OverviewofFeaturesonCH1andCH2 SBAU307A–December2017–RevisedMarch2018 PrecisionLabsSARADCEVM 5 SubmitDocumentationFeedback Copyright©2017–2018,TexasInstrumentsIncorporated EVMInitialSetup www.ti.com 2.2.1 AmplifierandADCInput(CH1andCH2) Figure3 showstheACinput(inputCH1)connectedtotheamplifierinput onthecouponboard.The output ofthecouponboardconnectstotheADS8860input.Bothchannel1and2havethissameconfiguration. TheDCinputsignalisgeneratedbyareferenceandvoltagedivider. Figure3.AmplifierandADCInput(CH1andCH2) 2.2.2 JumpersandReference(CH1andCH2) Figure4 showshowtheprecisionDCinput signalsaregeneratedusingareferencewithajumper- selectedvoltagedivider.DependingonthepositionofthejumperintheDCoptionsthedivideroutputis 0.1V,2.5V,3.5V,or4.9V.Ifthejumperisinthepositionshown, theoutputvoltageis0.1V.The amplifier U6bufferstheprecisionDCsignal.U8isthereferencefor channel1. Figure4.VoltageReferenceandJumper-SelectedVoltageDivider(CH1andCH2) 6 PrecisionLabsSARADCEVM SBAU307A–December2017–RevisedMarch2018 SubmitDocumentationFeedback Copyright©2017–2018,TexasInstrumentsIncorporated www.ti.com EVMInitialSetup Figure5 showsthejumpersettingsfora0.1-VDCinput.WhenusingDCinput mode,disconnecttheinput signalfromtheSMAconnector(inputCH2). Connect DC input from Reference AC_IN DC_IN 4.9V 3.5V PWR_5.2V PWR_3.3V PWR_PHI Apply 0.1V to 2.5V 0.1V SDI amplifier input AVDDDVDD CVST SAR ADS SCLK 5.2V IN- ADS8860 S2 SDO VIN IN+ VI S1 RSH COM REG GND GND N CSH P Input CH2 GND GND CDAC Disconnect AC Input S2 PHI_CH2 Signals when REF6050 GND GND using DC input DAQ Channel 2 Figure5.JumperPositionforaDCInputof0.1VonCH1andCH2 Figure6 showsthejumpersettingsforanACinput.WhenusingACinput mode, theDCjumperbankis ignored. AC input only connected AC_IN DC_IN 4.9V 3.5V PWR_5.2V PWR_3.3V PWR_PHI This jumper 2.5V bank is ignored 0.1V SDI in this mode. AVDDDVDD CVST SAR ADS SCLK 5.2V IN- ADS8860 S2 SDO VIN IN+ VI S1 RSH COM REG GND GND N CSH P Input CH2 GND GND CDAC Connect AC Input S2 PHI_CH2 REF6050 Signals using GND GND SMA Connector DAQ Channel 2 Figure6.JumperPositionforanACInputonCH1andCH2 SBAU307A–December2017–RevisedMarch2018 PrecisionLabsSARADCEVM 7 SubmitDocumentationFeedback Copyright©2017–2018,TexasInstrumentsIncorporated EVMInitialSetup www.ti.com 2.2.3 PowerSubsection(CH1andCh2) ThePHI-EVMcontrollergeneratesa5.5-VsupplywiththeUSBpower andachargepump.Figure 7 showsthe connectionbetweenthe5.5-Vsupplytotwodifferent low-noise,lowdropoutregulators (LDOs). U9generatesa5.2-VsupplyusedfortheamplifierandU11generatesthe3.3-Vsupplyusedbythe ADS8860. Figure7.Power Subsection(CH1andCH2) 8 PrecisionLabsSARADCEVM SBAU307A–December2017–RevisedMarch2018 SubmitDocumentationFeedback Copyright©2017–2018,TexasInstrumentsIncorporated www.ti.com EVMInitialSetup 2.2.4 ConnectiontothePHIControlerandEEPROM Figure8 showstheconnectorusedtointerfacethedigitalcontroller (PHI-EVM) andthePLABS-SAR- EVM.TheschematicalsoshowsanEEPROM that isusedfor boardidentification. Figure8.ConnectiontothePHIControllerandEEPROM SBAU307A–December2017–RevisedMarch2018 PrecisionLabsSARADCEVM 9 SubmitDocumentationFeedback Copyright©2017–2018,TexasInstrumentsIncorporated EVMInitialSetup www.ti.com 2.3 Channel 3 Operation Figure9 showsthefeaturesonCH3ofthePLABS-SAR-EVM.ThischannelallowsDCorACsignalsto be appliedto theADS7042.Plug-inamplifiercouponcardsareusedtoexperimentwithdifferent amplifier drivecircuits.Thechannelalsoprovidescurrent measurementcircuitryfor measuringtheanalogsupply current,digital supplycurrent,andamplifier supplycurrent.Thecurrentmeasurementcircuit hasjumper- selectedrangesforhighcurrent,lowcurrent, andcalibration.Current-shuntamplifiersandanADS1220 areusedtomeasurethecurrents.ThethreeLEDindicatorsaresharedbetweenthetwochannelsandare agoodquickchecktodetermineiftheboardispowered. Led power indicators Connector to digital controller PHI for CH3 PWR_5.2V PWR_3.3V PWR_PHI 2.5V AC or DC 1.5V LOW LOW LOW input selection 1.0V CAL CAL CAL 0.1V HIGH HIGH HIGH DC input for DC_IN Current Current Current CH1 and CH2 AVDD-AMP AVDD-ADC DVDD-AMP AC_IN VIAMP VIA VID 5.2V IN- AVDD_AMP AVDD DVDD VIN IN+ A A A GND GND GND GND VIN SAR ADC AC input CH4 Input ADS7042 S3 PHI_CH3 GND GND Power Scaling Channel 3 Test points for key Socket for signals and supplies amplifier Figure9.OverviewofFeaturesonCH3 10 PrecisionLabsSARADCEVM SBAU307A–December2017–RevisedMarch2018 SubmitDocumentationFeedback Copyright©2017–2018,TexasInstrumentsIncorporated