JiTEXASSZZA036BINSTRUMENTSDissectingtheTILogicDataSheetInthefollowingparagraphs,theTI logicdatasheetisdissected,andeverysectionandspecification isexplained indetail.SummaryDeviceDescriptionTitle, Literature Number,and Dates of Origination and RevisionThedevicenumberandtitleappearatthetopof everypage.Thedevicenumber isthenumberoftheparentdevice.ThefullyqualifiedpartnumberforaspecificdevicecanbefoundintheOrderablePartNumbertable.Figure11isacharttohelpdecodeinformation intheTIlogic-device part number.Theliteraturenumberisauniqueidentifierusedby TItoidentify,store,and retrieveadatasheetin internal files.The month and year of origination is the first date of publication of the data sheet. If a data sheetismodified,therevisiondate(monthandyear)isadded.Iftherearemultiplerevisions,onlythelatestrevisiondateappears16Understandingand Interpreting Standard-LogicData Sheets
SZZA036B 16 Understanding and Interpreting Standard-Logic Data Sheets Dissecting the TI Logic Data Sheet In the following paragraphs, the TI logic data sheet is dissected, and every section and specification is explained in detail. Summary Device Description Title, Literature Number, and Dates of Origination and Revision The device number and title appear at the top of every page. The device number is the number of the parent device. The fully qualified part number for a specific device can be found in the Orderable Part Number table. Figure 11 is a chart to help decode information in the TI logic-device part number. The literature number is a unique identifier used by TI to identify, store, and retrieve a data sheet in internal files. The month and year of origination is the first date of publication of the data sheet. If a data sheet is modified, the revision date (month and year) is added. If there are multiple revisions, only the latest revision date appears
iTEXASINSTRUMENTSSZZA036BExample:SN74LVC1G66DBVR237814569106StandardPrefixOptionsExamples:SNStandard PrefixExamples:Blank =No OptionsSNJ-Conforms to MIL-PRF-38535 (QML)2-Series Damping Resistor on Outputs4-Level Shifter2Temperature Range25-25-2 Line DriverExamples:54Military74-Commercial7Function3Family244-Noninverting Buffer/DriverExamples:Examples:Blank = Transistor-Transistor Logic (TTL)374-D-Type Flip-FlopABT-Advanced BiCMOSTechnology573-D-Type Transparent LatchABTE/ETL-Advanced BiCMOS Technologyl640-InvertingTransceiverEnhanced Transceiver Logic8.Device RevisionACIACT-Advanced CMOS LogicAHCIAHCT-AdvancedHigh-SpeedCMOS LogicExamples:Blank=No RevisionALB-Advanced Low-Voltage BiCMOSLetter Designator A-ZALS-Advanced Low-Power Schottky Logic9PackagesALVC-AdvancedLow-VoltageCMOSTechnologyCommercial:D,DW-Small-OutlineIntegratedCircuit(SOIC)ALVT-Advanced Low-VoltageBiCMOSTechnologyDB,DBQ,DCT,DLShrink Small-OutlinePackageAS-Advanced Schottky Logic(SSOP)AUC-Advanced Ultra Low-VoltageCMOSLogicDBB,DGV-Thin VerySmall-OutlinePackage (TVSOP)AVC-AdvancedVery Low-Voltage CMOSLogicDBQ-Quarter-SizeSmall-OutlinePackage(QSOP)BCT-BiCMOS Bus-interface TechnologyDBV,DCK,DCY,PK-Small-OuttineTransistor(SOT)CBT-CrossbarTechnologyDCU-VeryThin ShrinkSmall-OutlinePackage (VSSOP)CBTLV-Low-Voltage CrossbarTechnologyDGG,PW-ThinShrinkSmall-OutlinePackage(TSSOP)CD4000-CMOS B-Series Integrated CircuitsFN-Plastic Leaded Chip Carrier (PLCC)F-FLogicGGM, GKE, GKF,ZKE,ZKF-MicroStar BGATMFB-Backplane Transceiver Logic/Futurebus+Low-Profile Fine-Pitch Ball Grid Array (LFBGA)FCT-FastCMOSTTLLogicGQL,GQN,ZQL,ZQN-MicroStarJr.TGTL-Gunning Transceiver LogicVery-Thin-ProfileFine-PitchBall GridArray(VFBGA)GTLP-Gunning Transceiver Logic PlusN,NT,P_Plastic Dual-In-Line Package (PDIP)HC/HCT-High-SpeedCMOSLogicHSTL -High-Speed Transceiver LogicNS,PS-Small-OutlinePackage(SOP)PAG,PAH, PCA, PCB,PM,PN,PZ-ThinQuadLS Low-Power Schottky LogicFlatpack(TQFP)LV-Low-Voltage CMOS TechnologyPH, PQ, RC -Quad Flatpack (QFP)LVC-Low-Voltage CMOS TechnologyPZA-Low-Profile Quad Flatpack (LQFP)LVT-Low-Voltage BiCMOSTechnologyRGY-QuadFlatpackNoLead (QFN)PCA/PCF-12C inter-Integrated Circuit ApplicationsYEA,YZA-NanoStarMandNanoFreemS-SchottkyLogicDie-SizeBallGridArray (DSBGAt)SSTL/SSTV-StubSeries-Terminated LogicMilitary:FK-LeadlessCeramicChipCarrier(LCCC)TVC-Translation Voltage Clamp LogicGB-Ceramic Pin Grid Array (CPGA)VME-VERSAmodule Eurocard Bus TechnologyHFP,HS,HT,HV-CeramicQuadFlatpack(CQFP)4Special FeaturesJ.JT-CeramicDual-In-LinePackage(CDiP)Blank =No Special FeaturesExamples:W, WA, WD-Ceramic Flatpack (CFP)C-ConfigurableVcC (LVCC)D-Level-Shifting Diode (CBTD)10 Tape and ReelH-Bus Hold (ALVCH)Devices intheDBandPWpackagetypes includetheRdesignationK-Undershoot-ProtectionCircuitry(CBTK)for reeled product.Existing product inventory designated LEmayR-Damping Resistor on Inputs/Outputs (LVCR)remain, but all products are being converted to the R designation.S-Schottky Clamping Diode (CBTS)Z-Power-Up3-State(LVCZ)Old NomenclatureSN74LVTxxxDBLEExamples:5Bit WidthNewNomenclature-SN74LVTxxxADBRExamples:Blank=Gates,MSl,and OctalsLE-Left Embossed (validforDBandPWpackagesonly)1G-Single GateR-Standard (valid for all surface-mount packages)2G-Dual GateThere is no functional difference between LE and R designated3G-Triple Gateproducts, with respect to the carrier tape, cover tape, or reels used.8-Octal IEEE1149.1(JTAG)16-Widebus(16,18,and20 bit)18-WidebusIEEE1149.1(JTAG)↑DSBGA is the JEDEC referenceforwafer chip scale package (WCSP)32-Widebus+TM (32 and36bit)Figure11.DeviceNumberand PackageDesignators forTIDevices17Understanding and Interpreting Standard-LogicDataSheets
SZZA036B Understanding and Interpreting Standard-Logic Data Sheets 17 Figure 11. Device Number and Package Designators for TI Devices Examples: Blank = Transistor-Transistor Logic (TTL) ABT – Advanced BiCMOS Technology ABTE/ETL – Advanced BiCMOS Technology/ Enhanced Transceiver Logic AC/ACT – Advanced CMOS Logic AHC/AHCT – Advanced High-Speed CMOS Logic ALB – Advanced Low-Voltage BiCMOS ALS – Advanced Low-Power Schottky Logic ALVC – Advanced Low-Voltage CMOS Technology ALVT – Advanced Low-Voltage BiCMOS Technology AS – Advanced Schottky Logic AUC – Advanced Ultra Low-Voltage CMOS Logic AVC – Advanced Very Low-Voltage CMOS Logic BCT – BiCMOS Bus-Interface Technology CBT – Crossbar Technology CBTLV – Low-Voltage Crossbar Technology CD4000 – CMOS B-Series Integrated Circuits F – F Logic FB – Backplane Transceiver Logic/Futurebus+ FCT – Fast CMOS TTL Logic GTL – Gunning Transceiver Logic GTLP – Gunning Transceiver Logic Plus HC/HCT – High-Speed CMOS Logic HSTL – High-Speed Transceiver Logic LS – Low-Power Schottky Logic LV – Low-Voltage CMOS Technology LVC – Low-Voltage CMOS Technology LVT – Low-Voltage BiCMOS Technology PCA/PCF – I2C Inter-Integrated Circuit Applications S – Schottky Logic SSTL/SSTV – Stub Series-Terminated Logic TVC – Translation Voltage Clamp Logic VME – VERSAmodule Eurocard Bus Technology &!$ $ ) #$&'$ ! * # &'$% & & #& "!% '!& "! ( ( % "! % Examples: Blank = No Special Features C – Configurable VCC (LVCC) D – Level-Shifting Diode (CBTD) H – Bus Hold (ALVCH) K – Undershoot-Protection Circuitry (CBTK) R – Damping Resistor on Inputs/Outputs (LVCR) S – Schottky Clamping Diode (CBTS) Z – Power-Up 3-State (LVCZ) Examples: Blank = Gates, MSI, and Octals 1G – Single Gate 2G – Dual Gate 3G – Triple Gate 8 – Octal IEEE 1149.1 (JTAG) 16 – Widebus (16, 18, and 20 bit) 18 – Widebus IEEE 1149.1 (JTAG) 32 – Widebus+ (32 and 36 bit) Examples: Blank = No Options 2 – Series Damping Resistor on Outputs 4 – Level Shifter 25 – 25-Ω Line Driver Examples: 244 – Noninverting Buffer/Driver 374 – D-Type Flip-Flop 573 – D-Type Transparent Latch 640 – Inverting Transceiver Examples: Blank = No Revision Letter Designator A–Z Commercial: D, DW – Small-Outline Integrated Circuit (SOIC) DB, DBQ, DCT, DL – Shrink Small-Outline Package (SSOP) DBB, DGV – Thin Very Small-Outline Package (TVSOP) DBQ – Quarter-Size Small-Outline Package (QSOP) DBV, DCK, DCY, PK – Small-Outline Transistor (SOT) DCU – Very Thin Shrink Small-Outline Package (VSSOP) DGG, PW – Thin Shrink Small-Outline Package (TSSOP) FN – Plastic Leaded Chip Carrier (PLCC) GGM, GKE, GKF, ZKE, ZKF – MicroStar BGA Low-Profile Fine-Pitch Ball Grid Array (LFBGA) GQL, GQN, ZQL, ZQN – MicroStar Jr. Very-Thin-Profile Fine-Pitch Ball Grid Array (VFBGA) N, NT, P – Plastic Dual-In-Line Package (PDIP) NS, PS – Small-Outline Package (SOP) PAG, PAH, PCA, PCB, PM, PN, PZ – Thin Quad Flatpack (TQFP) PH, PQ, RC – Quad Flatpack (QFP) PZA – Low-Profile Quad Flatpack (LQFP) RGY – Quad Flatpack No Lead (QFN) YEA, YZA – NanoStar and NanoFree Die-Size Ball Grid Array (DSBGA†) # ! Examples: Old Nomenclature – SN74LVTxxxDBLE New Nomenclature – SN74LVTxxxADBR Examples: SN – Standard Prefix SNJ – Conforms to MIL-PRF-38535 (QML) Examples: 54 – Military 74 – Commercial Devices in the DB and PW package types include the R designation for reeled product. Existing product inventory designated LE may remain, but all products are being converted to the R designation. There is no functional difference between LE and R designated products, with respect to the carrier tape, cover tape, or reels used. LE – Left Embossed (valid for DB and PW packages only) R – Standard (valid for all surface-mount packages) Military: FK – Leadless Ceramic Chip Carrier (LCCC) GB – Ceramic Pin Grid Array (CPGA) HFP, HS, HT, HV – Ceramic Quad Flatpack (CQFP) J, JT – Ceramic Dual-In-Line Package (CDIP) W, WA, WD – Ceramic Flatpack (CFP) ) # † DSBGA is the JEDEC reference for wafer chip scale package (WCSP).
TEXASSZZA036BINSTRUMENTSSpecial featuresof TI standard logic devices are designated in thedevicenumberbyabbreviations,as listedbelowanddefinedinthefollowingparagraphs.Blank-NospecialfeaturesC- Configurable VccD-Level-shifting diodeH-Bus holdK-Undershoot-protectioncircuitryR-Dampingresistoroninputs/outputsS-SchottkyclampingdiodeZ-Power-up3-stateConfigurable Vcc (C)ConfigurableVcc is afeature ofdevices that are designedas dual-supply levelshifters,e.g.,SN74LVCC3245andSN74LVCC4245.Usingthesedevicesallowsselectionofthevoltagetobeapplied to Vcc on the B-port side (VccB) and/or A-port side (VccA) (seeFigure 12)'4245Pinning*245 PinningUVCCBVCCA!LVCC3245DIR OVCCB"LVCC4245No Internal ConnectionA1 dJOE·dB1:9.·d.'424·9I.:9..95.·.6.GNDGNDGNDVCCAVCCBTRANSLATIONBPORTAPORT(BIDIRECTIONALFLOW)3 V-5.5VSN74LVCC3245A2.3V-3.6V2.5Vto3.3Vor3.3Vto5V5V3 V-5V5Vto 3.3 VSN74LVCC4245AFigure12.ExampleofConfigurableVccDevicesDesignerscanusethesedevicesinexistingsingle-voltagesystems.Whensystemsbecomemixed-voltagesystems,thesedevicesdonotneedtobereplaced,allowingforquickertimetomarket.Level-Shifting Diode (D)DeviceswithDaspartof thedevicenumberhavean integrateddiodeintheVccline.ExamplesarecrossbarswitchesSN74CBTD3306(withtheintegrateddiode)andSN74CBT3306(withoutthe integrated diode).These devices allow 5-V to3.3-V translation if nodrive is requiredBidirectionaldatatransmissionisallowedbetween5-VTTLand3.3-VLVTTL,whereasonlyunidirectionalleveltranslationisallowedfrom5-VCMOSto3.3-VLVTTL(seeFigure13).Theintegrateddiodesavesdesignersbothboardspaceandcomponentcost.18Understanding and Interpreting Standard-LogicData Sheets
SZZA036B 18 Understanding and Interpreting Standard-Logic Data Sheets Special features of TI standard logic devices are designated in the device number by abbreviations, as listed below and defined in the following paragraphs. Blank – No special features C – Configurable VCC D – Level-shifting diode H – Bus hold K – Undershoot-protection circuitry R – Damping resistor on inputs/outputs S – Schottky clamping diode Z – Power-up 3-state Configurable VCC (C) Configurable VCC is a feature of devices that are designed as dual-supply level shifters, e.g., SN74LVCC3245 and SN74LVCC4245. Using these devices allows selection of the voltage to be applied to VCC on the B-port side (VCCB) and/or A-port side (VCCA) (see Figure 12). VCCA DIR A1 • • • • • • • GND GND VCCB VCCB OE B1 • • • • • • • GND ’4245 Pinning ’LVCC3245 ’LVCC4245 No Internal Connection ’245 Pinning ’424 VCCA A PORT VCCB B PORT TRANSLATION (BIDIRECTIONAL FLOW) SN74LVCC3245A 2.3 V–3.6 V 3 V–5.5 V 2.5 V to 3.3 V or 3.3 V to 5 V SN74LVCC4245A 5 V 3 V–5 V 5 V to 3.3 V Figure 12. Example of Configurable VCC Devices Designers can use these devices in existing single-voltage systems. When systems become mixed-voltage systems, these devices do not need to be replaced, allowing for quicker time to market. Level-Shifting Diode (D) Devices with D as part of the device number have an integrated diode in the VCC line. Examples are crossbar switches SN74CBTD3306 (with the integrated diode) and SN74CBT3306 (without the integrated diode). These devices allow 5-V to 3.3-V translation if no drive is required. Bidirectional data transmission is allowed between 5-V TTL and 3.3-V LVTTL, whereas only unidirectional level translation is allowed from 5-V CMOS to 3.3-V LVTTL (see Figure 13). The integrated diode saves designers both board space and component cost
TEXASINSTRUMENTSSZZA036BVcc=5VCBTDCBTOE3.3-V5-VSystemSystem-μP-ASIC-μcRAM-DSP二5-Vto3-VTranslation5SN74CBT4SN74CBTD192234TOVi- VFigure13.CBTvsCBTDWithInternalDiodeBus-Hold (H)Abus-holdcircuitisimplementedinselectedlogicfamiliestohelpsolvethefloating-inputprobleminherentinallCMOSinputs(refertotheapplicationreport,ImplicationsofSloworFloatingCMOsInputs,literaturenumberSCBAo04).Thebus-holdcircuitmaintainsthelastknowninputstateintothedeviceandasanadditionalbenefit,pulluporpulldownresistorsnolongerareneeded(seeFigure14).Theadvantagesofdeviceswiththiscircuitareboard-spacesavingsandreducedcomponentcostsVccDeviceBus-HoldCircuitOutputInputBusBusFigure14.BenefitofUsingBus-HoldDevices19UnderstandingandInterpretingStandard-LogicDataSheets
SZZA036B Understanding and Interpreting Standard-Logic Data Sheets 19 VCC = 5 V VI – V 1 2 234 5 3 4 5 1 0 5-V to 3-V Translation SN74CBT SN74CBTD CBTD CBT 5-V System – ASIC – RAM OE 3.3-V System – µP – µC – DSP VO – V Figure 13. CBT vs CBTD With Internal Diode Bus-Hold (H) A bus-hold circuit is implemented in selected logic families to help solve the floating-input problem inherent in all CMOS inputs (refer to the application report, Implications of Slow or Floating CMOS Inputs, literature number SCBA004). The bus-hold circuit maintains the last known input state into the device and, as an additional benefit, pullup or pulldown resistors no longer are needed (see Figure 14). The advantages of devices with this circuit are board-space savings and reduced component costs. Bus-Hold Circuit Device VCC Input Bus Output Bus Figure 14. Benefit of Using Bus-Hold Devices
TEXASSZZA036BINSTRUMENTSDampingResistoronInputs/Outputs (R)Series dampingresistors (SDR),denoted by R in thedevicenumber,are included atallinput/outputand output ports of designated devices (seeFigure 15).The SDRs limit the current,thereby reducing signal undershoot and overshoot noise.Additionally,SDRs make linetermination easier,which improves signal quality by reducingringing and line reflectionsVccSDRFromInternalOutputLogicCircuitryFigure15.Series-Damping-ResistorOptionSchottkyClampingDiode(S)Schottkydiodes are incorporated in inputs and outputs to clamp undershoot (seeFigure16),TheSchottky diodes preventundershoot signalsfromdroppingbelowa specifiedlevel,reducingthe possibility of damageto connected devices by largeundershoots that can occurwithout theSchottkydiodes.1A1B10Figure16.SchottkyClamping-DiodeDeviceSchematicUndershoot-ProtectionCircuitry (K)TI undershoot-protection circuitry (UPC)functions similarlyto Schottky clamping diodes,withonemajordifference.UPC is an active clamping structure.UPC can greatly reduce undershootvoltage,increasingprotectionfromcorrupteddata(seeFigure17)20Understandingand InterpretingStandard-LogicDataSheets
SZZA036B 20 Understanding and Interpreting Standard-Logic Data Sheets Damping Resistor on Inputs/Outputs (R) Series damping resistors (SDR), denoted by R in the device number, are included at all input/output and output ports of designated devices (see Figure 15). The SDRs limit the current, thereby reducing signal undershoot and overshoot noise. Additionally, SDRs make line termination easier, which improves signal quality by reducing ringing and line reflections. From Internal Output SDR Logic Circuitry VCC Figure 15. Series-Damping-Resistor Option Schottky Clamping Diode (S) Schottky diodes are incorporated in inputs and outputs to clamp undershoot (see Figure 16). The Schottky diodes prevent undershoot signals from dropping below a specified level, reducing the possibility of damage to connected devices by large undershoots that can occur without the Schottky diodes. 1A 1B 1OE Figure 16. Schottky Clamping-Diode Device Schematic Undershoot-Protection Circuitry (K) TI undershoot-protection circuitry (UPC) functions similarly to Schottky clamping diodes, with one major difference. UPC is an active clamping structure. UPC can greatly reduce undershoot voltage, increasing protection from corrupted data (see Figure 17)