Magnitude Binary Number Comparator

This post is labeled under Digital Design


Applying further the principles of Boolean Algebra theorems, Truth Tables and K-maps, we could create a magnitude comparator in designing a circuit.

Magnitude comparator is a combinational circuit that compares two numbers A & B to
determine whether A > B, or A = B, or A < B. n in Figure 1 represents the numbers of bits A and B have. Exactly one of the outputs will be set to 1 (HIGH) and the two other outputs should set to 0’s (LOW).


74LS85 IC chip is a 4-bit magnitude comparator commercially available normally produced by semiconductor company such as Fairchild Semiconductor. Cascading this chip can create magnitude binary comparator higher than 4 bits.

Below is an experiment on how to design a 2-bit binary number comparator.
Magnitude Comparator Experiment 6