© 2000 Fairchild Semiconductor Corporation

DS006421

www.fairchildsemi.com

August 1986

Revised March 2000

DM74LS283

4-Bit Binary Adder with Fast Carry

General Description

These full adders perform the addition of two 4-bit binary

numbers. The sum (

∑) 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 look-

ahead 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

s Full-carry look-ahead across the four bits

s Systems achieve partial look-ahead performance with

the economy of ripple carry

s Typical add times

Two 8-bit words

25 ns

Two 16-bit words 45 ns

s Typical power dissipation per 4-bit adder 95 mW

Ordering Code:

Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.

Connection Diagram

Order Number

Package Number

Package Description

DM74LS283M

M16A

16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow

DM74LS283N

N16E

16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide