Topic 2(Logic Gates and Boolean Algebra)

Boolean algebra

allows only two
values—0 and 1.
• Logic 0 can be: false, off, low,
no, open switch.
• Logic 1 can be: true, on, high,
yes, closed switch.

Truth Tables

describes the relationship between the input and
output of a logic circuit.

2^n

How to calculate the number of combinations for inputs and outputs

Total number of columns

What is the sum of inputs and outputs called?

Electric Circuit

Consist of at least a transistor, capacitor and a resistor.

Digital Circuit

-input and output signal

-Logic gates

-using 1,0

-uses Boolean algebra

-uses Boolean constants (Logic 1,0)

-True, False

-High, Low

The relationship of the input and the output

what are we only interested in a digital circuit?

Bubble

Bubble

is placed anywhere in a logic diagram, it means
inversion. That is, if we have a “1” on one side of the bubble,
then we have a “0” on the other side.

NOT/Inverter

NOT/Inverter

Outputs the opposite of its single input (0 → 1, 1 → 0).

OR

OR

Outputs 1 if at least one input is 1.

A bar

What is the Boolean expression of NOT gate

A+B

What is the Boolean expression of the OR gate

NOR

NOR

Outputs the inverse of OR, so it’s 1 only if all inputs are 0.

A+B bar

What is the Boolean expression of NOR?

AND

AND

Outputs 1 only if all inputs are 1.

AB

What is the Boolean expression of AND

NAND

NAND

Outputs the inverse of AND, so it’s 0 only if all inputs are 1.

AB bar

What is the Boolean expression of NAND

Black box

is a conceptual model that is understood only by the relationship between its inputs and outputs, with its internal workings hidden or irrelevant.

Logic gates

are the smallest functional units in digital logic.

Digital Circuit

If you were to form logic gates together you will get a?

Boolean algebra and truth table

What are the two methods in finding the circuit output

Prime (‘)

Another word and symbol for bar (-)

PNAO

What is the acronym for order of operations in Boolean algebra?

Parenthesis, NOT, AND, OR

What does PNAO stands for?

No

Are they the same?

Buffer

Buffer

is used to strengthen or isolate signals so they can drive more loads without distortion.

Buffer

is a gate that outputs the same logic level as its input.