Full-Carry Look-Ahead Across the

Four Bits

Systems Achieve Partial Look-Ahead

Performance With the Economy of Ripple

Carry

Package Options Include Plastic

Small-Outline Packages, Ceramic Chip

Carriers, and Standard Plastic and Ceramic

300-mil DIPs

description

The ′F283 is a full adder that performs the addition

of two 4-bit binary words. The sum (Σ) outputs are

provided for each bit and the resultant carry (C4)

output is obtained from the fourth bit.

The device features full internal look-ahead

across all four bits generating the carry term C4 in

typically 5.7 ns. This capability 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. End-around carry

can be accomplished without the need for logic or

level inversion.

The ′F283 can be used with either all-active-high

(positive logic) or all-active-low (negative logic)

operands.

The SN54F283 is characterized for operation over

the full military temperature range of −55°C to

125°C. The SN74F283 is characterized for

operation from 0°C to 70°C.