1. Logic Gates

2. AND Function
Output Y is TRUE if inputs A AND B are TRUE, else it is FALSE.
Logic Symbol 
Text Description 
Truth Table 
Boolean Expression 
AND A B Y
AND Symbol
Y = A x B = A • B = AB

3. OR Function
Output Y is TRUE if input A OR B is TRUE, else it is FALSE.
Logic Symbol 
Text Description 
Truth Table 
Boolean Expression  A B Y OR
OR Symbol
Y = A + B

4. NOT Function (inverter)
Output Y is TRUE if input A is FALSE, else it is FALSE. Y is the inverse of A.
Text Description 
Logic Symbol  A Y
NOT
Truth Table 
Y = A’
Alternative Notation
Y = !A
NOT Bar
Boolean Expression 
Y = A

5. NAND Function
Output Y is FALSE if inputs A AND B are TRUE, else it is TRUE.
Logic Symbol 
Text Description 
Truth Table 
Boolean Expression 
A bubble is an inverter
This is an AND Gate with an inverted output A B Y
NAND
Y = A x B = AB

6. NOR Function
Output Y is FALSE if input A OR B is TRUE, else it is TRUE.
Logic Symbol 
Text Description 
Truth Table 
Boolean Expression 
A bubble is an inverter.
This is an OR Gate with its output inverted. A B Y
NOR
Y = A + B

7. Circuit-to-Truth Table ExampleOR A Y
NOT
AND B C
A B C Y
2# of Inputs = # of Combinations
2 3 = 8

8. Circuit-to-Truth Table ExampleOR A Y
NOT
AND B C 1
A B C Y

9. Circuit-to-Truth Table ExampleOR A Y
NOT
AND B C 1
A B C Y

10. Circuit-to-Truth Table ExampleOR A Y
NOT
AND B C 1
A B C Y 1

11. Circuit-to-Truth Table ExampleOR A Y
NOT
AND B C 1
A B C Y 1

12. Circuit-to-Truth Table ExampleOR A Y
NOT
AND B C 1
A B C Y 1

13. Circuit-to-Truth Table ExampleOR A Y
NOT
AND B C 1
A B C Y 1

14. Circuit-to-Truth Table ExampleOR A Y
NOT
AND B C 1
A B C Y 1

15. Circuit-to-Truth Table ExampleOR A Y
NOT
AND B C 1
A B C Y 1

16. Circuit-to-Boolean Equation
A B OR A Y
NOT
AND B C
= A B + A C A 1 } 1 }
A C
A B C Y

17. A - O - I Logic AND Gates NAND - NAND Logic OR Gates NOR - NOR LogicY
NOT
AND B C
AND Gates
Other Logic Arrangements:
NAND - NAND Logic
NOR - NOR Logic
OR Gates
INVERTER Gates

18. NAND Gate – Special Application
S T A B Y
NAND 1
Equivalent To An Inverter Gate

19. NOR Gate - Special Application
S T A B Y
NOR 1
Equivalent To An Inverter Gate