Lecture notes Logic gates and Boolean algebra

26/08/2020




Digital Electronics:
Combinational Logic

Logic Gates and Boolean
Algebra




Introduction to Logic Gates
• We will introduce Boolean algebra and
logic gates
• Logic gates are the building blocks of
digital circuits




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, 26/08/2020




Logic Variables
• Different names for the same thing
– Logic variables
– Binary variables
– Boolean variables
• Can only take on 2 values, e.g.,
– TRUE or False
– ON or OFF
– 1 or 0




Logic Variables
• In electronic circuits the two values can
be represented by e.g.,
– High voltage for a 1
– Low voltage for a 0
• Note that since only 2 voltage levels are
used, the circuits have greater immunity
to electrical noise




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