Subject: Industrial Electronics

Topic: Digital logic and Logic families

Difficulty: Medium

De Morgan's Theorem:-

There are two theorems -

De Morgan's First Theorem:-

Statement - The complement of a logical sum equals the logical product of the complements.

Logic equation - $ \bar {A+B} = \bar A .\bar B$

Proof -

NOR gate is equivalent to bubbled AND gate.

De Morgan's Second Theorem:-

Statement - The complement of a logical product equals the logical sum of the complements.

Logic equation - $ \bar {A.B} = \bar A + \bar B$

Proof -

NAND gate is equivalent to bubbled OR gate.

Truth Table to prove De Morgan's Theorem:-