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54LS83A/DM54LS83A/DM74LS83A4-Bit Binary Adders with Fast CarryGeneral DescripTIonThese full adders perform the addiTIon of two 4-bit binarynumbers. The sum (R) outputs are provided for each bit andthe resultant carry (C4) is obtained from the fourth bit.These adders feature full internal look ahead across all fourbits. This provides the system designer with parTIal lookaheadperformance at the economy and reduced packagecount of a ripple-carry implementaTIon.The adder logic, including the carry, is implemented in itstrue form meaning that the end-around carry can be accomplishedwithout the need for logic or level inversion.FeaturesY Full-carry look-ahead across the four bitsY Systems achieve partial look-ahead performance withthe economy of ripple carryY Typical add timesTwo 8-bit words 25 nsTwo 16-bit words 45 nsY Typical power dissipation per 4-bit adder 95 mWY Alternate Military/Aerospace device (54LS83A) is available.Contact a National Semiconductor Sales Office/Distributor for specifications.
