Four-Bit Binary Adder

Only available on StudyMode
  • Pages : 7 (1095 words )
  • Download(s) : 296
  • Published : March 16, 2011
Open Document
Text Preview
SN54/74LS83A 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, B 1 – 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 16 Σ4 15 C4 14 C0 13 GND 12 B1 11 A1 10 Σ1 9

NOTE: The Flatpak version has the same pinouts (Connection Diagram) as the Dual In-Line Package.

4-BIT BINARY FULL ADDER WITH FAST CARRY
LOW POWER SCHOTTKY

J SUFFIX CERAMIC CASE 620-09
16 1

1 A4

2 Σ3

3 A3

4 B3

5 VCC

6 Σ2

7 B2

8 A2 LOADING (Note a) HIGH LOW 0.5 U.L. 0.5 U.L. 0.25 U.L. 5 (2.5) U.L. 5 (2.5) U.L. 16 1

PIN NAMES

N SUFFIX PLASTIC CASE 648-08

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.

16 1

D SUFFIX SOIC CASE 751B-03

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.

ORDERING INFORMATION
SN54LSXXJ SN74LSXXN SN74LSXXD Ceramic Plastic SOIC

LOGIC DIAGRAM
C0 A1
13 10

B1
11

A2
8

B2
7

A3
3

B3
4

A4
1

B4
16

VCC = PIN 5 GND = PIN 12 = PIN NUMBERS

LOGIC SYMBOL
10 11 8 7 3 4 1 16 B1 A2 B2 A3 B3 A4 B4 C4 ∑1∑2 ∑3 ∑4 C4 9 6 2 15 14

13

C0

14

C1

C2

C3

9

6

2

15

14

∑1

∑2

∑3

∑4

C4

FAST AND LS TTL DATA 5-81

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: C0 Logic Levels Active HIGH Active LOW L 0 1 A1 L 0 1 A2 H 1 0 A3 L 0 1 A4 H 1 0 B1 H 1 0 B2 L 0 1 B3 L 0 1 B4 H 1 0 ∑1 H 1 0 ∑2 H 1 0 ∑3 L 0 1 ∑4 L 0 1 C4 H 1 0 (10+9 = 19) (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) L L L L H H H H An L L H H L L H H Bn L H L H L H L H ∑n L H H L H L L H Cn L L L H L H H H

C1 — C3 are generated internally C0 — is an external input C4 — is an output generated internally

GUARANTEED OPERATING RANGES
Symbol VCC TA IOH IOL Supply Voltage Operating Ambient Temperature Range Output Current — High Output Current — Low Parameter 54 74 54 74 54, 74 54 74 Min 4.5 4.75 – 55 0 Typ 5.0 5.0 25 25 Max 5.5 5.25 125 70 – 0.4 4.0 8.0 Unit V °C mA mA

FAST AND LS TTL DATA 5-82

SN54/74LS83A
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified) Limits Symbol VIH VIL VIK VOH Parameter Input HIGH Voltage 54 Input LOW Voltage 74 Input Clamp Diode Voltage 54 Output HIGH Voltage 74 54, 74 VOL Output LOW Voltage 74 Input HIGH Current C0 A or B C0 A or B IIL IOS ICC Input LOW Current C0 A or B Output Short Circuit Current (Note 1) Power Supply Current All Inputs Grounded All Inputs at 4.5 V, Except B All Inputs at 4.5 V – 20 0.35 0.5 V µA 2.7 3.5 0.25 0.4 V V 2.5 – 0.65 3.5 0.8 – 1.5 V V Min 2.0 0.7 V Typ Max Unit V Test Conditions Guaranteed Input HIGH Voltage for All Inputs Guaranteed Input LOW Voltage for All Inputs VCC = MIN, IIN...
tracking img