74LS83 4-bit Full Adder IC

You are currently viewing 74LS83 4-bit Full Adder IC
  • Post author:
  • Reading time:2 mins read

The 74LS83 is a high speed 4-bit fuller Adder IC with carry out feature. The IC has four independent stages of full adder circuits in a single package. It is commonly used in applications where arithmetic operations are involved.  

74LS83 Pin Configuration

Pin NumberPin NameDescription
10,8,3,1A1, A2, A3, A4First Input for the adder circuit (Four pin for four stages)  
11,7,4,16B1, B2, B3, B4Second Input for the adder circuit (Four pin for four stages)  
13C0Carry Input – from previous stage if present. 
9,6,2,15S1, S2, S3, S4Output pin for the Adder circuit (Four pin for four stages)  
14C4Carry Out pin to cascade with other ICs. 

Specifications – 74LS83

  • 4-bit Full Adder with Carry Out
  • Nominal Operating Voltage: 5V
  • Maximum Operating Voltage: 5.5V 
  • Output Propagation delay: 16nS
  • Maximum Input Low Voltage: 0.8V
  • Minimum Input High Voltage: 2V
  • Available in 16-pin PDIP, CDIP,SOIC, TSSOP packages

Where to use 74LS83 IC

Although today we have cheap microcontrollers that could perform all arithmetic operations required for our application, in early days the ICs like Adder, Counter, flip-flops etc were used for same.  This way the complexity and the BOM cost of the circuit design will greatly go low. 

The 74LS83 is a Full Adder with Carry in and Carry out feature. It is a four stage 4-bit counter, meaning it has four individual Full adder circuits each of 4-bit inside a single package. It can also be easily cascaded if more than four stages are required.

How to use a 74HC83 Full Adder IC

Using the Full Adder IC is pretty much straight forward. The IC has four different stages and each stage has two normal inputs Ax and Bx with an additional carry input called C1. Based on the values provided to these pins the output Sx will either be high (logic 1) or low (logic 0). The IC also has a Carry Out (CO) pin which will go high if the result has an carry. The block diagram below represents the same.

74HC83 block diagram

Each Full adder stage will obey the truth table below. Where Ai, Bi and Ci are the input and SUM, Co are the outputs.

74HC83 full adder truth table


  • High Speed Arithmetic operations 
  • Miniature calculators 
  • Counters 
  •  Simple logic control designs 

Farees Ahmed

The aim of this blog is to serve as a quick reference guide for the Curious. Appreciate your feedback and comments !