DM74LS283

Features:

 Full-carry look-ahead across the four bits
 Systems achieve partial look-ahead performance with the economy of ripple carry
 Typical add times
   Two 8-bit words 25 ns
   Two 16-bit words 45 ns
 Typical power dissipation per 4-bit adder 95 mW
 Alternate Military/Aerospace device (54LS283) is available. Contact a National Semiconductor Sales Office/Distributor for specifications.


Specifications

Supply Voltage                                                                   7V
Input Voltage                                                                     7V
Operating Free Air Temperature Range
DM54LS and 54LS                                       -55ßC to 125
DM74LS                                                             0 to 70
Storage Temperature Range                        -65to 150



Description

   These DM74LS283 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 DM74LS283 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 DM74LS283 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.