54LS83A/DM54LS83A/DM74LS83A
4-Bit Binary Adders with Fast Carry
General Description
These full adders perform the addition of two 4-bit binary
numbers. The sum (R) outputs are provided for each bit and
the resultant carry (C4) is obtained from the fourth bit.
These adders feature full internal look ahead across all four
bits. This provides the system designer with partial lookahead
performance at the economy and reduced package
count of a ripple-carry implementation.
The adder logic, including the carry, is implemented in its
true form meaning that the end-around carry can be accomplished
without the need for logic or level inversion.
Features
Y Full-carry look-ahead across the four bits
Y Systems achieve partial look-ahead performance with
the economy of ripple carry
Y Typical add times
Two 8-bit words 25 ns
Two 16-bit words 45 ns
Y Typical power dissipation per 4-bit adder 95 mW
Y Alternate Military/Aerospace device (54LS83A) is available.
Contact a National Semiconductor Sales Office/
Distributor for specifications.