1. Types of Operational Amplifiers1

2. 2 - Introduction - Single Stage Op-Amplifier
outline
- Introduction
- Single Stage Op-Amplifier
- Folded Cascode Op-Amplifier
- Design and Analysis Two Stage Op-Amplifier 2

3. Introduction
It easy to define an Op-Amp. as "a high gain deferential amplifier". It is mean that a value that is adequate for the application. The gain could be anywhere from 101 to 106 .
Many other aspects of performance had to sacrificed; such as power, output swing and speed.
Most of today s' CMOS op-amp have a high output impedance (in open loop). As such, they called "transconductance amplifiers". 3

4. 4 Role of Op-Amplifiers Specifications Requirements
- Widely used building blocks for analog circuits, Mixed
Signals.
- Widely used in analog signal processing and
communication circuits
Specifications Requirements
- High DC Gain
- Large Gain-Bandwidth/ High Speed
- Sufficient Output Swing
- High power efficiency 4

5. 1- Single Stage Op-Amp.
The MOSFET converts the input gate-source voltage to drain current, which can pass through a load to generate an output voltage. 5

6. 6 2- Cascode Amplifier DC Gain: High Speed: Excellent
Power diss.: High
Freq. Response: Good
Output Swing: Small 6

7. 7 3- Two Stage Op-Amp Design and analysis DC Gain: Modest Speed: Good
Power diss. : Good
Freq. Response: Good
Output Swing: Good 7

8. 3- Two Stage Op-Amp Design and analysis8

9. Frequency response AV p1 p2 z2
UGF z1 w
-90 PM
-180 9

10. HOMEWORK
Design a two-stage CMOS Op-Amp. by using a 0.18 µTechnology and calculate the aspect ratio of each PMOS and NMOS. The design parameters are:
Parameter
Value
Vdd
1.8 CL
1 pF SR
50 V/µs Kp
93 x10-6A/V2 Kn
168 x10-6/V2
VTp
-0.39V
VTn
0.32V
Phase Margin
60º Cc
0.22 C GB
80 MHZ 10