电子技术-芯片资料-7485.pdf

TL/F/65305485/DM5485/DM7485 4-Bit Magnitude ComparatorsJune 19895485/DM5485/DM74854-Bit Magnitude ComparatorsGeneral DescriptionThese 4-bit magnitude comparators perform comparison ofstraight binary or BCD codes.Three fully-decoded decisionsabout two 4-bit words(A,B)are made and are externallyavailable at three outputs.These devices are fully expand-able to any number of bits without external gates.Words ofgreater length may be compared by connecting compara-tors in cascade.The AlB,AkB,and AeB outputs of astage handling less-significant bits are connected to the cor-responding inputs of the next stage handling more-signifi-cant bits.The stage handling the least-significant bits musthave a high-level voltage applied to the AeB input.Thecascading paths are implemented with only a two-gate-leveldelay to reduce overall comparison times for long words.FeaturesYTypical power dissipation 275 mWYTypical delay(4-bit words)23 nsYAlternate Military/Aerospace device(5485)is available.Contact a National Semiconductor Sales Office/Distrib-utor for specifications.Connection DiagramDual-In-Line PackageTL/F/65301Order Number 5485DMQB,5485FMQB,DM5485J,DM5485W or DM7485NSee NS Package Number J16A,N16E or W16AC1995 National Semiconductor CorporationRRD-B30M105/Printed in U.S.A.Absolute Maximum Ratings(Note)If Military/Aerospace specified devices are required,pleasecontacttheNationalSemiconductorSalesOffice/Distributors for availability and specifications.Supply Voltage7VInput Voltage5.5VOperating Free Air Temperature RangeDM54 and 54b55C toa125CDM740C toa70CStorage Temperature Rangeb65C toa150CNote:The Absolute Maximum Ratings are those valuesbeyond which the safety of the device cannot be guaran-teed.The device should not be operated at these limits.Theparametric values defined in the Electrical Characteristicstable are not guaranteed at the absolute maximum ratings.The Recommended Operating Conditions table will definethe conditions for actual device operation.Recommended Operating ConditionsSymbolParameterDM5485DM7485UnitsMinNomMaxMinNomMaxVCCSupply Voltage4.555.54.7555.25VVIHHigh Level Input Voltage22VVILLow Level Input Voltage0.80.8VIOHHigh Level Output Currentb0.8b0.8mAIOLLow Level Output Current1616mATAFree Air Operating Temperatureb55125070CElectrical Characteristicsover recommended operating free air temperature range(unless otherwise noted)SymbolParameterConditionsMinTypMaxUnits(Note 1)VIInput Clamp VoltageVCCeMin,IIe b12 mAb1.5VVOHHigh Level OutputVCCeMin,IOHeMax2.4VVoltageVILeMax,VIHeMinVOLLow Level OutputVCCeMin,IOLeMax0.4VVoltageVIHeMin,VILeMaxIIInput CurrentMaxVCCeMax,VIe5.5V1mAInput VoltageIIHHigh Level InputVCCeMaxAkB40CurrentVIe2.4VAlB40mAOthers120IILLow Level InputVCCeMaxAkBb1.6CurrentVIe0.4VAlBb1.6mAOthersb4.8IOSShort CircuitVCCeMaxDM54b20b55mAOutput Current(Note 2)DM74b18b55ICCSupply CurrentVCCeMax5588mA(Note 3)Note 1:All typicals are at VCCe5V,TAe25C.Note 2:Not more than one output should be shorted at a time.Note 3:ICCis measured with all outputs open,AeB input grounded and all other inputs at 4.5V.2Switching Characteristicsat VCCe5V and TAe25C(See Section 1 for Test Waveforms and Output Load)FromToNumber ofRLe400XSymbolParameterInputOutputGate LevelsCLe15 pFUnitsMinMaxtPLHPropagation Delay TimeAny A or BAkB326Low-to-High Level OutputData InputAlBnsAeB435tPHLPropagation Delay TimeAny A or BAkB330High-to-Low Level OutputData InputAlBnsAeB430tPLHPropagation Delay TimeAkBAlB111nsLow-to-High Level Outputor AeBtPHLPropagation Delay TimeAkBAlB117nsHigh-to-Low Level Outputor AeBtPLHPropagation Delay TimeAeBAeB220nsLow-to-High Level OutputtPHLPropagation Delay TimeAeBAeB217nsHigh-to-Low Level OutputtPLHPropagation Delay TimeAlBAkB111nsLow-to-High Level Outputor AeBtPHLPropagation Delay TimeAlBAkB117nsHigh-to-Low Level Outputor AeBFunction TableComparingCascadingOutputsInputsInputsA3,B3A2,B2A1,B1A0,B0AlBAkBAeBAlBAkBAeBA3lB3XXXXXXHLLA3kB3XXXXXXLHLA3eB3A2lB2XXXXXHLLA3eB3A2kB2XXXXXLHLA3eB3A2eB2A1lB1XXXXHLLA3eB3A2eB2A1kB1XXXXLHLA3eB3A2eB2A1eB1A0lB0XXXHLLA3eB3A2eB2A1eB1A0kB0XXXLHLA3eB3A2eB2A1eB1A0eB0HLLHLLA3eB3A2eB2A1eB1A0eB0LHLLHLA3eB3A2eB2A1eB1A0eB0LLHLLHA3eB3A2eB2A1eB1A0eB0XXHLLHA3eB3A2eB2A1eB1A0eB0HHLLLLA3eB3A2eB2A1eB1A0eB0LLLHHLHeHigh Level,LeLow Level,XeDont Care3Logic DiagramTL/F/653024Physical Dimensionsinches(millimeters)16-Lead Ceramic Dual-In-Line Package(J)Order Number 5485DMQB or DM5485JNS Package Number J16A16-Lead Molded Dual-In-Line Package(N)Order Number DM7485NNS Package Number N16E55485/DM5485/DM7485 4-Bit Magnitude ComparatorsPhysical Dimensionsinches(millimeters)(Continued)16-Lead Ceramic Flat Packge(W)Order Number 5485FMQB or DM5485WNS Package Number W16ALIFE SUPPORT POLICYNATIONALS PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORTDEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONALSEMICONDUCTOR CORPORATION.As used herein:1.Lifesupportdevicesorsystemsaredevicesor2.A critical component is any component of a lifesystems which,(a)are intended for surgical implantsupport device or system whose failure to perform caninto the body,or(b)support or sustain life,and whosebe reasonably expected to cause the failure of the lifefailure to perform,when properly used in accordancesupport device or system,or to affect its safety orwith instructions for use provided in the labeling,caneffectiveness.be reasonably expected to result in a significant injuryto the user.National SemiconductorNational SemiconductorNational SemiconductorNational SemiconductorCorporationEuropeHong Kong Ltd.Japan Ltd.1111 West Bardin RoadFax:(a49)0-180-530 85 8613th Floor,Straight Block,Tel:[phone]Arlington,TX 76017Email:Ocean Centre,5 Canton Rd.Fax:[phone]Tel:[phone]Deutsch Tel:(a49)0-180-530 85 85Tsimshatsui,KowloonFax:1(800)737-7018EnglishTel:(a49)0-180-532 78 32Hong KongFran3ais Tel:(a49)0-180-532 93 58Tel:[phone]ItalianoTel:(a49)0-180-534 16 80Fax:[phone]National does not assume any responsibility for use of any circuitry described,no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.