4-Bit Binary Full Adders With Fast Carry

The ´F283 is a full adder that performs the addition of two 4-bit binary words. The sum ( ) 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.