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FAST CARRY. SN54LS83A Datasheet |
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4-BIT BINARY FULL ADDER
WITH FAST CARRY
The SN54 / 74LS83A 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 LS83A operates with either
active HIGH or active LOW operands (positive or negative logic). The
SN54 / 74LS283 is recommended for new designs since it is identical in
function with this device and features standard corner power pins.
CONNECTION DIAGRAM DIP (TOP VIEW)
B4 Σ4 C4 C0 GND B1 A1 Σ1
16 15 14 13 12 11 10 9
NOTE:
The Flatpak version has the
same pinouts (Connection
Diagram) as the Dual In-Line
Package.
12
A4 Σ3
3 4 56
A3 B3 VCC Σ2
78
B2 A2
PIN NAMES
LOADING (Note a)
HIGH
LOW
A1 – A4
B1 – B4
C0
Σ1 – Σ4
C4
Operand A Inputs
Operand B Inputs
Carry Input
Sum Outputs (Note b)
Carry Output (Note b)
1.0 U.L.
1.0 U.L.
0.5 U.L.
10 U.L.
10 U.L.
0.5 U.L.
0.5 U.L.
0.25 U.L.
5 (2.5) 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.
C0 A1 B1
13 10 11
A2 B2
87
LOGIC DIAGRAM
A3 B3
34
A4 B4
1 16
VCC = PIN 5
GND = PIN 12
= PIN NUMBERS
SN54/74LS83A
4-BIT BINARY FULL ADDER
WITH FAST CARRY
LOW POWER SCHOTTKY
16
1
J SUFFIX
CERAMIC
CASE 620-09
16
1
N SUFFIX
PLASTIC
CASE 648-08
16
1
D SUFFIX
SOIC
CASE 751B-03
ORDERING INFORMATION
SN54LSXXJ
SN74LSXXN
SN74LSXXD
Ceramic
Plastic
SOIC
LOGIC SYMBOL
10 11 8 7 3 4 1 16
B1 A2 B2 A3 B3 A4 B4
13 C0
C4
∑1∑2 ∑3∑4 C4
9 6 2 15 14
14
C1 C2
C3
96
∑1 ∑2
2
∑3
15
∑4
14
C4
FAST AND LS TTL DATA
5-81
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SN54 / 74LS83A
FUNCTIONAL DESCRIPTION
The LS83A 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 LS83A 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:
Logic Levels
Active HIGH
Active LOW
C0 A1 A2 A3 A4 B1 B2 B3 B4 ∑1 ∑2 ∑3 ∑4
L L H L HH L L H H H L L
C4
H
0 01 0 11 0 0 1 1 1 0 0
1 (10+9 = 19)
1 10 1 00 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 10, 11,
13, etc.
FUNCTIONAL TRUTH TABLE
C (n–1)
An
Bn
∑n
L LLL
L LHH
L HLH
L HHL
H LLH
H LHL
H HLL
H HHH
C1 — C3 are generated internally
C0 — is an external input
C4 — is an output generated internally
Cn
L
L
L
H
L
H
H
H
GUARANTEED OPERATING RANGES
Symbol
Parameter
VCC
Supply Voltage
TA Operating Ambient Temperature Range
IOH Output Current — High
IOL Output Current — Low
Min Typ Max Unit
54 4.5 5.0 5.5
74 4.75 5.0 5.25
V
54 – 55 25 125 °C
74 0 25 70
54, 74
– 0.4
mA
54 4.0 mA
74 8.0
FAST AND LS TTL DATA
5-82
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SN54 / 74LS83A
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified)
Symbol
Parameter
Limits
Min Typ Max
Unit
Test Conditions
VIH Input HIGH Voltage
2.0
V
Guaranteed Input HIGH Voltage for
All Inputs
54
VIL Input LOW Voltage
74
0.7 Guaranteed Input LOW Voltage for
0.8 V All Inputs
VIK
VOH
Input Clamp Diode Voltage
Output HIGH Voltage
54
74
– 0.65 – 1.5 V VCC = MIN, IIN = – 18 mA
2.5 3.5
2.7 3.5
V VCC = MIN, IOH = MAX, VIN = VIH
V per Truth Table
VOL
Output LOW Voltage
54, 74
74
0.25 0.4
0.35 0.5
V IOL = 4.0 mA VCC = VCC MIN,
VIN = VIL or VIH
V IOL = 8.0 mA per Truth Table
Input HIGH Current
C0
IIH A or B
C0
A or B
20 µA VCC = MAX, VIN = 2.7 V
40
0.1
0.2 mA VCC = MAX, VIN = 7.0 V
Input LOW Current
IIL C0
A or B
– 0.4 mA VCC = MAX, VIN = 0.4 V
– 0.8
IOS Output Short Circuit Current (Note 1) – 20
–100 mA VCC = MAX
ICC Power Supply Current
All Inputs Grounded
All Inputs at 4.5 V, Except B
All Inputs at 4.5 V
39
34
mA VCC = MAX
34
Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.
AC CHARACTERISTICS (TA = 25°C)
Symbol
tPLH
tPHL
tPLH
tPHL
tPLH
tPHL
tPLH
tPHL
Parameter
Propagation Delay, C0 Input
to any Σ Output
Propagation Delay, Any A or
B Input to Σ Outputs
Propagation Delay, C0 Input
to C4 Output
Propagation Delay, Any A or
B Input to C4 Output
Limits
Min Typ Max
16 24
15 24
15 24
15 24
11 17
15 22
11 17
12 17
Unit
ns
ns
ns
ns
Test Conditions
VCC = 5.0 V
CL = 15 pF
Figures 1 and 2
AC WAVEFORMS
VIN
VOUT
1.3 V
tPHL
1.3 V
1.3 V
tPLH
1.3 V
Figure 1
VIN
VOUT
1.3 V
tPLH
1.3 V
1.3 V
tPHL
1.3 V
Figure 2
FAST AND LS TTL DATA
5-83
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