SDFS069A − D2932, MARCH 1987 − REVISED OCTOBER 1993
Copyright 1993, Texas Instruments Incorporated
2−1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
POST OFFICE BOX 1443 • HOUSTON, TEXAS 77251−1443
•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.
logic symbol†
Σ
0
6
B1
0
5
A1 3
A2 14
A3
3
12
A4
2
B2 15
B3
3
11
B4
CI
7
C0
C4
9
CO
Σ1
4
01
13
10
3
Σ2
Σ3
Σ4
P
Q
Σ
†This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
Pin numbers shown are for the D, J, and N packages.
SN74F283 ...D OR N PACKAGE
(TOP VIEW)
3212019
910111213
4
5
6
7
8
18
17
16
15
14
A3
Σ3
NC
A4
B4
A2
Σ1
NC
A1
B1
SN54F283 . . . FK PACKAGE
(TOP VIEW)
B2
Σ
NC
C4
4B3
C0
GND
NC
NC − No internal connection
VCC
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
Σ2
B2
A2
Σ1
A1
B1
C0
GND
VCC
B3
A3
Σ3
A4
B4
Σ4
C4
2
Σ
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