2. What is Logic Gates?
๏ต Logicgates in binary system is
use to represent process and
operation for binary
information in matematic.
3. AND Function
Output Y is TRUE if inputs A AND B are
Text Description
TRUE, else it is FALSE.
A
Logic Symbol AND Y
B
INPUTS OUTPUT
A B Y
0 0 0
Truth Table 0 1 0
1 0 0
1 1 1
AND Gate Truth Table
AND Symbol
Boolean Expression Y = A x B = A โข B = AB
4. OR Function
Output Y is TRUE if input A OR B is
Text Description
TRUE, else it is FALSE.
A
Logic Symbol OR Y
B
INPUTS OUTPUT
A B Y
0 0 0
Truth Table 0 1 1
1 0 1
1 1 1
OR Gate Truth Table
OR Symbol
Boolean Expression Y=A+B
5. NOT Function (inverter)
Text Description Output Y is TRUE if input A is FALSE,
else it is FALSE. Y is the inverse of
A.
Logic Symbol A NOT Y
INPUT OUTPUT
A Y
0 1
Truth Table 1 0
NOT Gate Truth Table
NOT Alternative Notation
Bar
Boolean Expression Y=A Y = Aโ
Y = !A
6. NAND Function
Output Y is FALSE if inputs A AND B
Text Description
are TRUE, else it is TRUE.
A bubble is an inverter
A This is an AND Gate with an inverted output
Logic Symbol NAND Y
B
INPUTS OUTPUT
A B Y
0 0 1
Truth Table 0 1 1
1 0 1
1 1 0
NAND Gate Truth Table
Boolean Expression Y = A x B = AB
7. NOR Function
Output Y is FALSE if input A OR B is
Text Description
TRUE, else it is TRUE.
A bubble is an inverter.
A This is an OR Gate with its output inverted.
Logic Symbol NOR Y
B
INPUTS OUTPUT
A B Y
0 0 1
Truth Table 0 1 0
1 0 0
1 1 0
NOR Gate Truth Table
Boolean Expression Y=A+B
8. Symbol:
A
C
B
Ex-OR
Output C is FALSE if inputs A and B are same value,
else output is TRUE.
9. Get Exclusive (EX-OR)
INPUTS OUTPUT
Truth Table A B C
0 0 0
0 1 1
1 0 1
1 1 0
EX-OR Gate Truth Table
Boolean Expression
10. Symbol:
A
C
B
Ex-NOR
Output C is TRUE if inputs A and B are same value, else
output is FALSE.
11. Get Exclusive (EX-NOR)
INPUTS OUTPUT
Truth Table
A B C
0 0 1
0 1 0
1 0 0
1 1 1
EX-NOR Gate Truth Table
Boolean Expression
12. Circuit-to-Truth Table Example
A
AND
B
OR Y
NOT
AND
C A B C Y
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
2# of Inputs = # of Combinations 1 0 1
1 1 0
23 = 8 1 1 1
13. Circuit-to-Truth Table Example
0 0
A
0 AND
B
0
OR Y
1
NOT 0
0 AND
C
A B C Y
0 0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
14. Circuit-to-Truth Table Example
0 0
A
0 AND
B
1
OR Y
1
NOT 1
1 AND
C
A B C Y
0 0 0 0
0 0 1 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
15. Circuit-to-Truth Table Example
0 0
A
1 AND
B
0
OR Y
1
NOT 0
0 AND
C
A B C Y
0 0 0 0
0 0 1 1
0 1 0 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
16. Circuit-to-Truth Table Example
0 0
A
1 AND
B
1
OR Y
1
NOT 1
1 AND
C
A B C Y
0 0 0 0
0 0 1 1
0 1 0 0
0 1 1 1
1 0 0
1 0 1
1 1 0
1 1 1
17. Circuit-to-Truth Table Example
1 0
A
0 AND
B
0
OR Y
0
NOT 0
0 AND
C
A B C Y
0 0 0 0
0 0 1 1
0 1 0 0
0 1 1 1
1 0 0 0
1 0 1
1 1 0
1 1 1
18. Circuit-to-Truth Table Example
1 0
A
0 AND
B
0
OR Y
0
NOT 0
1 AND
C
A B C Y
0 0 0 0
0 0 1 1
0 1 0 0
0 1 1 1
1 0 0 0
1 0 1 0
1 1 0
1 1 1
19. Circuit-to-Truth Table Example
1 1
A
1 AND
B
1
OR Y
0
NOT 0
0 AND
C
A B C Y
0 0 0 0
0 0 1 1
0 1 0 0
0 1 1 1
1 0 0 0
1 0 1 0
1 1 0 1
1 1 1
20. Circuit-to-Truth Table Example
1 1
A
1 AND
B
1
OR Y
0
NOT 0
1 AND
C
A B C Y
0 0 0 0
0 0 1 1
0 1 0 0
0 1 1 1
1 0 0 0
1 0 1 0
1 1 0 1
1 1 1 1
21. Circuit-to-Boolean Equation
AB
A
AND
B
OR Y =AB + AC
A
}
}
NOT
AND
C
AC A B C Y
0 0 0 0
0 0 1 1
0 1 0 0
0 1 1 1
1 0 0 0
1 0 1 0
1 1 0 1
1 1 1 1
22. A - O - I Logic
A
AND
B
OR Y
NOT
AND
C
AND Gates
Other Logic Arrangements:
OR Gates NAND - NAND Logic
INVERTER Gates NOR - NOR Logic
23. NAND Gate โ Special Application
S NAND T
S T
0 1 A
1
1 0 NAND Y
B
INPUTS OUTPUT
A B Y
0 0 1
Equivalent To An Inverter Gate 0 1 1
1 0 1
1 1 0
24. NOR Gate - Special Application
S NOR T
S T
0 1 A
1
1 0 NOR Y
B
INPUTS OUTPUT
A B Y
0 0 1
0 1 0
1 0 0
Equivalent To An Inverter Gate 1 1 0
