5-1
FAST AND LS TTL DATA
4-BIT BINARY FULL ADDER
WITH FAST CARRY
The SN54/74LS283 is a high-speed 4-Bit Binary Full Adder with internal
carry lookahead. It accepts two 4-bit binary words (A1–A4, B1–B4) and a
Carry Input (C0). It generates the binary Sum outputs (∑1–∑4) and the Carry
Output (C4) from the most significant bit. The LS283 operates with either ac-
tive HIGH or active LOW operands (positive or negative logic).
14 13 12 11 10 9
1 2 3 4 5 6 7
16 15
8
VCC
Σ
2
B3A3
Σ
3A4
Σ
4
B4C4
B2A2
Σ
1A1B1C0GND
CONNECTION DIAGRAM DIP (TOP VIEW)
NOTE:
The Flatpak version
has the same pinouts
(Connection Diagram) as
the Dual In-Line Package.
PIN NAMES LOADING (Note a)
HIGH LOW
A1–A4Operand A Inputs 1.0 U.L. 0.5 U.L.
B1–B4Operand B Inputs 1.0 U.L. 0.5 U.L.
C0Carry Input 0.5 U.L. 0.25 U.L.
∑1–∑4Sum Outputs (Note b) 10 U.L. 5 (2.5) U.L.
C4Carry Output (Note b) 10 U.L. 5 (2.5) U.L.
NOTES:
a) 1 TTL Unit Load (U.L.) = 40 µA HIGH/1.6 mA LOW.
b) The Output LOW drive factor is 2.5 U.L. for Military (54) and 5 U.L. for Commercial
(74) Temperature Ranges.
SN54/74LS283
4-BIT BINARY FULL ADDER
WITH FAST CARRY
LOW POWER SCHOTTKY
ORDERING INFORMATION
SN54LSXXXJ Ceramic
SN74LSXXXN Plastic
SN74LSXXXD SOIC
J SUFFIX
CERAMIC
CASE 620-09
N SUFFIX
PLASTIC
CASE 648-08
16 1
16
1
16 1
D SUFFIX
SOIC
CASE 751B-03
LOGIC SYMBOL
5 3 14 12 6 2 15 11
97
4 1 13 10
A1A2A3A4B1B2B3B4
∑
1
∑
2
∑
3
∑
4
VCC = PIN 16
GND = PIN 8
C0C4
5-2
FAST AND LS TTL DATA
SN54/74LS283
LOGIC DIAGRAM
C0A1B1A2B2A3B3A4B4
∑
1
∑
2
∑
3
∑
4C4
VCC = PIN 16
GND = PIN 8
= PIN NUMBERS
C1C2C3
14
1
267 3
4
5
9
11
12
10
13
15
FUNCTIONAL DESCRIPTION
The LS283 adds two 4-bit binary words (A plus B) plus the
incoming carry. The binary sum appears on the sum outputs
(∑1–∑4) and outgoing carry (C4) outputs.
C0 + (A1 + B1) + 2(A2 + B2) + 4(A3 + B3) + 8(A4 + B4) = ∑1 + 2 ∑2
+ 4 ∑3 + 8 ∑4 + 16C4
Where: (+) = plus
Due to the symmetry of the binary add function the LS283
can be used with either all inputs and outputs active HIGH
(positive logic) or with all inputs and outputs active LOW
(negative logic). Note that with active HIGH inputs, Carry Input
can not be left open, but must be held LOW when no carry in is
intended.
Example:
C0A1A2A3A4B1B2B3B4∑1∑2∑3∑4C4
logic levels L L H L H H L L H H H L L H
Active HIGH 0 0 1 0 1 1 0 0 1 1 1 0 0 1 (10+9=19)
Active LOW 1 1 0 1 0 0 1 1 0 0 0 1 1 0 (carry+5+6=12)
Interchanging inputs of equal weight does not affect the operation, thus C0, A1, B1, can be arbitrarily assigned to pins 7, 5 or 3.
5-3
FAST AND LS TTL DATA
SN54/74LS283
FUNCTIONAL TRUTH TABLE
C (n–1) AnBn∑nCn
L L L L L
L L H H L
L H L H L
L H H L H
H L L H L
H L H L H
H H L L H
H H H H H
C1–C3 are generated internally
C0 is an external input
C4 is an output generated internally
GUARANTEED OPERATING RANGES
Symbol Parameter Min Typ Max Unit
VCC Supply Voltage 54
74 4.5
4.75 5.0
5.0 5.5
5.25 V
TAOperating Ambient Temperature Range 54
74 –55
025
25 125
70 °C
IOH Output Current — High 54, 74 –0.4 mA
IOL Output Current — Low 54
74 4.0
8.0 mA
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified)
Symbol
Parameter
Limits
Unit
Test Conditions
Symbol
Parameter
Min Typ Max
Unit
Test Conditions
VIH Input HIGH Voltage 2.0 V Guaranteed Input HIGH Voltage for
All Inputs
VIL
Input LOW Voltage
54 0.7
V
Guaranteed Input LOW Voltage for
All Inputs
VIL
Input LOW Voltage
74 0.8
V
Guaranteed Input LOW Voltage for
All Inputs
VIK Input Clamp Diode Voltage –0.65 –1.5 V VCC = MIN, IIN = –18 mA
VOH
Output HIGH Voltage
54 2.5 3.5 V
V
CC = MIN, IOH = MAX, VIN = VIH
or VIL per Truth Table
VOH
Output HIGH Voltage
74 2.7 3.5 V
VCC = MIN, IOH = MAX, VIN = VIH
or VIL per Truth Table
VOL
Output LOW Voltage
54, 74 0.25 0.4 V IOL = 4.0 mA
VCC = VCC MIN,
VIN = VIL or VIH
per Truth Table
VOL
Output LOW Voltage
74 0.35 0.5 V IOL = 8.0 mA
VIN = VIL or VIH
per Truth Table
IIH
Input HIGH Current
C020 µA
VCC = MAX, VIN = 2.7 V
IIH
Input HIGH Current
Any A or B 40 µA
VCC = MAX, VIN = 2.7 V
IIH
Input HIGH Current
C00.1 mA
VCC = MAX, VIN = 7.0 V
Any A or B 0.2 mA
VCC = MAX, VIN = 7.0 V
IIL
Input LOW Current
C0–0.4 mA
VCC = MAX, VIN = 0.4 V
IIL
Input LOW Current
Any A or B –0.8 mA
VCC = MAX, VIN = 0.4 V
IOS Short Circuit Current (Note 1) –20 –100 mA VCC = MAX
I
CC
Power Supply Current
Total, Output HIGH 34
mA V
CC = MAX
ICC
Total, Output LOW 39
mA
VCC = MAX
Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.
5-4
FAST AND LS TTL DATA
SN54/74LS283
AC CHARACTERISTICS (TA = 25°C, VCC = 5.0 V)
Symbol
Parameter
Limits
Unit
Test Conditions
Symbol
Parameter
Min Typ Max
Unit
Test Conditions
tPLH
tPHL Propagation Delay, C0 Input
to Any Σ Output 16
15 24
24 ns
CL = 15 pF
Figures 1 & 2
tPLH
tPHL Propagation Delay, Any A or B Input
to Σ Outputs 15
15 24
24 ns
C
L = 15 pF
Figures 1 & 2
tPLH
tPHL Propagation Delay, C0 Input
to C4 Output 11
11 17
22 ns
CL = 15 pF
Figures 1 & 2
tPLH
tPHL Propagation Delay, Any A or B Input
to C4 Output 11
12 17
17 ns
Figure 1 Figure 2
VIN
VOUT
1.3 V
1.3 V
1.3 V
1.3 V
VIN
VOUT
tPHL tPLH tPLH tPHL
AC WAVEFORMS
