This document discusses CMOS logic gates and compound gates used in microelectronic circuits. It describes the structure and truth tables of basic CMOS gates like NAND and how series and parallel combinations of nMOS and pMOS transistors implement different logic functions. The document also introduces several examples of compound gates including AND-AND-OR-INVERT (AOI22) and OR-OR-INVERT (O3AI) and how they can implement any inverting logic function through different connections of basic gates. Truth tables are provided to illustrate the output logic function for various inputs.

1. Dr. S.Meenatchi Sundaram, Department of Instrumentation & Control Engineering, MIT, Manipal
ICE 4010: MICRO ELECTRO
MECHANICAL SYSTEMS (MEMS)
Lecture #05
CMOS Logic Gates
Dr. S. Meenatchi Sundaram
Email: meenasundar@gmail.com
1

2. CMOS NAND Gate
2Dr. S. Meenatchi Sundaram, Department of Instrumentation & Control Engineering, MIT, Manipal
A B Y
0 0
0 1
1 0
1 1
A
B
Y

3. CMOS NAND Gate
3Dr. S. Meenatchi Sundaram, Department of Instrumentation & Control Engineering, MIT, Manipal
A B Y
0 0 1
0 1
1 0
1 1
A=0
B=0
Y=1
OFF
ON ON
OFF

4. CMOS NAND Gate
4Dr. S. Meenatchi Sundaram, Department of Instrumentation & Control Engineering, MIT, Manipal
A B Y
0 0 1
0 1 1
1 0
1 1
A=0
B=1
Y=1
OFF
OFF ON
ON

5. CMOS NAND Gate
5Dr. S. Meenatchi Sundaram, Department of Instrumentation & Control Engineering, MIT, Manipal
A B Y
0 0 1
0 1 1
1 0 1
1 1
A=1
B=0
Y=1
ON
ON OFF
OFF

6. CMOS NAND Gate
6Dr. S. Meenatchi Sundaram, Department of Instrumentation & Control Engineering, MIT, Manipal
A B Y
0 0 1
0 1 1
1 0 1
1 1 0

7. CMOS NAND Gate
7Dr. S. Meenatchi Sundaram, Department of Instrumentation & Control Engineering, MIT, Manipal

8. Series and Parallel
8
• nMOS: 1 = ON
• pMOS: 0 = ON
• Series: both must be ON
• Parallel: either can be ON
Dr. S. Meenatchi Sundaram, Department of Instrumentation & Control Engineering, MIT, Manipal
(a)
a
b
a
b
g1
g2
0
0
a
b
0
1
a
b
1
0
a
b
1
1
OFF OFF OFF ON
(b)
a
b
a
b
g1
g2
0
0
a
b
0
1
a
b
1
0
a
b
1
1
ON OFF OFF OFF
(c)
a
b
a
b
g1 g2 0 0
OFF ON ON ON
(d) ON ON ON OFF
a
b
0
a
b
1
a
b
11 0 1
a
b
0 0
a
b
0
a
b
1
a
b
11 0 1
a
b
g1 g2

9. Compound Gates
9
• Compound gates can do any inverting function
• Ex:
Dr. S. Meenatchi Sundaram, Department of Instrumentation & Control Engineering, MIT, Manipal
(AND-AND-OR-INVERT, AOI22)Y A B C D= +i i
A
B
C
D
A
B
C
D
A B C D
A B
C D
B
D
Y
A
C
A
C
A
B
C
D
B
D
Y
(a)
(c)
(e)
(b)
(d)
(f)

10. Compound Gates
10
• O3AI
• Ex:
Dr. S. Meenatchi Sundaram, Department of Instrumentation & Control Engineering, MIT, Manipal
( )Y A B C D= + + i
A B
Y
C
D
DC
B
A

11. Compound Gates
11Dr. S. Meenatchi Sundaram, Department of Instrumentation & Control Engineering, MIT, Manipal

12. Compound Gates
12Dr. S. Meenatchi Sundaram, Department of Instrumentation & Control Engineering, MIT, Manipal

13. Compound Gates
13Dr. S. Meenatchi Sundaram, Department of Instrumentation & Control Engineering, MIT, Manipal
a b ā ࢈ഥ T1 T2 T3 T4 T5 T6 T7 T8 Y
0 0 1 1 OFF ON ON ON OFF ON OFF OFF OFF
0 1 1 0 ON ON ON OFF OFF OFF OFF ON ON
1 0 0 1
1 1 0 0
T1
T2
T3
T4
T5
T6
T7
T8

14. Compound Gates
14
• A EXOR B
Dr. S. Meenatchi Sundaram, Department of Instrumentation & Control Engineering, MIT, Manipal