4位超前进位加法器

TL F 642154LS283 DM54LS283 DM74LS283 4-Bit Binary Adders with Fast CarryJune1989 54LS283 DM54LS283 DM74LS2834-Bit Binary Adders with Fast CarryGeneral DescriptionThese full adders perform the addition of two4-bit binarynumbers The sum(R)outputs are provided for each bit andthe resultant carry(C4)is obtained from the fourth bitThese adders feature full internal look ahead across all fourbits This provides the system designer with partial look-ahead performance at the economy and reduced packagecount of a ripple-carry implementationThe adder logic including the carry is implemented in itstrue form meaning that the end-around carry can be accom-plished without the need for logic or level inversionFeaturesY Full-carry look-ahead across the four bitsY Systems achieve partial look-ahead performance withthe economy of ripple carryY Typical add timesTwo8-bit words25nsTwo16-bit words45nsY Typical power dissipation per4-bit adder95mWY Alternate Military Aerospace device(54LS283)is avail-able Contact a National Semiconductor Sales OfficeDistributor for specificationsConnection DiagramDual-In-Line PackageTL F 6421–1Order Number54LS283DMQB 54LS283FMQB 54LS283LMQBDM54LS283J DM54LS283W DM74LS283M or DM74LS283NSee NS Package Number E20A J16A M16A N16E or W16AC1995National Semiconductor Corporation RRD-B30M105 Printed in U S AAbsolute Maximum Ratings(Note)If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Supply Voltage7V Input Voltage7V Operating Free Air Temperature RangeDM54LS and54LS b55 C to a125 C DM74LS0 C to a70 C Storage Temperature Range b65 C to a150 C Note The‘‘Absolute Maximum Ratings’’are those values beyond which the safety of the device cannot be guaran-teed The device should not be operated at these limits The parametric values defined in the‘‘Electrical Characteristics’’table are not guaranteed at the absolute maximum ratings The‘‘Recommended Operating Conditions’’table will define the conditions for actual device operationRecommended Operating ConditionsSymbol ParameterDM54LS283DM74LS283Units Min Nom Max Min Nom MaxV CC Supply Voltage4 555 54 7555 25V V IH High Level Input Voltage22V V IL Low Level Input Voltage0 70 8V I OH High Level Output Current b0 4b0 4mA I OL Low Level Output Current48mA T A Free Air Operating Temperature b55125070 C Electrical Characteristics over recommended operating free air temperature range(unless otherwise noted)Symbol Parameter Conditions MinTypMax Units (Note1)V I Input Clamp Voltage V CC e Min I I e b18mA b1 5V V OH High Level Output V CC e Min I OH e Max DM542 53 4V Voltage V IL e Max V IH e Min DM742 73 4V OL Low Level Output V CC e Min I OL e Max DM540 250 4 Voltage V IL e Max V IH e Min DM740 350 5VI OL e4mA V CC e Min DM740 250 4I I Input Current Max V CC e Max A B0 2mA Input Voltage V I e7V C00 1I IH High Level Input V CC e Max A B40m A Current V I e2 7V C020I IL Low Level Input V CC e Max A B b0 8mA Current V I e0 4V C0b0 4I OS Short Circuit V CC e Max DM54b20b100mA Output Current(Note2)DM74b20b100I CC1Supply Current V CC e Max(Note3)1934mA I CC2Supply Current V CC e Max(Note4)2239mA Note1 All typicals are at V CC e5V T A e25 CNote2 Not more than one output should be shorted at a time and the duration should not exceed one secondNote3 I CC1is measured with all outputs open all B inputs low and all other inputs at4 5V or all inputs at4 5VNote4 I CC2is measured with all outputs open and all inputs grounded2Switching Characteristics at V CC e5V and T A e25 C(See Section1for Test Waveforms and Output Load)From(Input)R L e2k XSymbol ParameterTo(Output)C L e15pF C L e50pF UnitsMin Max Min Maxt PLH Propagation Delay Time C0to2428ns Low to High Level Output R1 R2t PHL Propagation Delay Time C0to2430ns High to Low Level Output R1 R2t PLH Propagation Delay Time C0to2428ns Low to High Level Output R3t PHL Propagation Delay Time C0to2430ns High to Low Level Output R3t PLH Propagation Delay Time C0to2428ns Low to High Level Output R4t PHL Propagation Delay Time C0to2430ns High to Low Level Output R4t PLH Propagation Delay Time A i or B i2428ns Low to High Level Output to R it PHL Propagation Delay Time A i or B i2430ns High to Low Level Output to R it PLH Propagation Delay Time C0to1724ns Low to High Level Output C4t PHL Propagation Delay Time C0to1725ns High to Low Level Output C4t PLH Propagation Delay Time A i or B i1724ns Low to High Level Output to C4t PHL Propagation Delay Time A i or B i1726ns High to Low Level Output to C4Function TableTL F 6421–3 H e High Level L e Low LevelNote Input conditions at A1 B1 A2 B2 and C0are used to determine outputs R1and R2and the value of the internal carry C2 The values at C2 A3 B3 A4 andB4are then used to determine outputs R3 R4 and C43Logic DiagramLS283TL F 6421–245Physical Dimensions inches(millimeters)Ceramic Leadless Chip Carrier Package(E)Order Number54LS283LMQBNS Package Number E20A16-Lead Ceramic Dual-In-Line Package(J)Order Number54LS283DMQB or DM54LS283JNS Package Number J16A6Physical Dimensions inches(millimeters)(Continued)16-Lead Small Outline Molded Package(M)Order Number DM74LS283MNS Package Number M16A16-Lead Molded Dual-In-Line Package(N)Order Number DM74LS283NNS Package Number N16E754L S 283 D M 54L S 283 D M 74L S 2834-B i t B i n a r y A d d e r s w i t h F a s t C a r r yPhysical Dimensions inches (millimeters)(Continued)16-Lead Ceramic Flat Package (W)Order Number 54LS283FMQB or DM54LS283WNS Package Number W16ALIFE SUPPORT POLICYNATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION As used herein 1 Life support devices or systems are devices or 2 A critical component is any component of a life systems which (a)are intended for surgical implant support device or system whose failure to perform can into the body or (b)support or sustain life and whose be reasonably expected to cause the failure of the life failure to perform when properly used in accordance support device or system or to affect its safety or with instructions for use provided in the labeling can effectivenessbe reasonably expected to result in a significant injury to the userNational Semiconductor National Semiconductor National Semiconductor National Semiconductor CorporationEuropeHong Kong LtdJapan Ltd1111West Bardin RoadFax (a 49)0-180-530858613th Floor Straight Block Tel 81-043-299-2309This datasheet has been downloaded from: Datasheets for electronic components.。