Design  Of  OP-AMP
CMOS Introduction
CMOS Amplifier
Amplifier characteristics
Output dynamic range
Bandwidth and rise time
Settling time and aberrations
Slew rate
Electronic amplifiers
Two-Stage Amplifier
Design  Of  OP-AMP
Design Of Two Stage OP-AMP

An operational amplifier, usually referred to as an op-amp for brevity, is a DC-coupled high-gain electronic voltage amplifier with differential inputs and, usually, a single output. In its typical usage, the output of the op-amp is controlled by negative feedback which largely determines the magnitude of its output voltage gain, input impedance at one of its input terminals and output impedance.


Op-amps are among the most widely used electronic devices today, being used in a vast array of consumer, industrial, and scientific devices.


The design of an OPAMP can be divided into two distinct design-related activities that are for the  most part independent of one another. The first of these activities involves choosing or creating the basic structure of the opamp. A diagram that describes the interconnection of all of the transistors results. In most cases , this structure doesn’t change throughout the remaining portion of the design, but sometimes certain characteristics of the chosen design must be changed by modifying structure.


Boundary Conditions:

·        Process specification

·        Supply voltage and range

·        Supply current and range

·        Operating temperature and range

Requirements and Specifications:

·        Gain                            >=70dB

·        Gain Bandwidth            >=5MHz

·        Settling Time               <=1us

·        Slew Rate                    >=5 V/us

·        ICMR                           >=+-1.5 V

·        CMRR                          >=60dB

·        PSRR                           >=60dB

·        Output Swing               >=+-1.5 V

·        Output Resistance         Not Applicable

·        Offset                          <=+-10mV

·        Noise                           <=100 nV/(Hz)1/2 at 1 KHz

·        Layout Area           <=5000*(min Channel Length)2   






The contents of this webpage are copyrighted © 2008
 All Rights Reserved.