CSEIT1951191 | Received : 02 Jan 2019 | Accepted : 25 Jan 2019 | January-February -2019 [ 5 (1) : 574-585 ]
International Journal of Scientific Research in Computer Science, Engineering and Information Technology
© 2019 IJSRCSEIT | Volume 5 | Issue 1 | ISSN : 2456-3307
574
Implementation and Characterization of High Slew Rate CMOS
Op-Amp
Dr. Priyesh P. Gandhi
General Manager, Prakruti Consultancy Services, Vadodara, Gujarat, India
ABSTRACT
Operational Amplifiers (Op-Amp) are one of the most widely used building blocks for analog and mixed-signal
systems. They are employed from dc bias applications to high speed amplifiers and filters. Different
architectures like Two-Stage Op-Amp and Folded Cascode Op-Amp are simulated with different characteristics
like slew rate, offset voltage, gain. For improving the slew rate, few modifications are carried out by adding
current replication branch and auxiliary circuits in Op-Amp.
Keywords : Operational Amplifiers (Op-Amp), Slew Rate, CMOS, Propagation delay, Offset Voltage, Power
Dissipation.
I. INTRODUCTION
An Operational Amplifier is a high-gain direct-
coupled amplifier that is remarkably used in feedback
connections. The word Operational Amplifier
evolved from original applications in analog
computation where the circuits are used to perform
various mathematical operations like summation,
integration, subtraction & derivation. Due to the
performance and economic advantages of available
units, present applications extend far beyond from
the original applications, modern Op-Amps are used
as general purpose analog data-processing elements.
[12] .
The range of Op-Amp usage began to expand toward
the present spectrum of applications in the early
1960s because various manufacturers were
developing modular, solid-state circuits. As the
improvement in processing and designs, the
integrated circuit will invade more areas once
considered exclusively the domain of the discrete
design, and it is probable that the days of the
discrete-component circuit, except for specials with
limited production requirements, are numbered.[13]
Figure 1. Circuit symbol of Op-Amp
An Operational Amplifier (Op-Amp) is an integrated
circuit (IC) which operates as a voltage amplifier. It
has a differential input. That mean, it has two inputs
which are in opposite polarity. An Op-Amp has a
very high gain and single output, which means that
the output signal is a large amount than input signal.
An Op-Amp is regularly represented in a circuit
diagram as shown in figure 1.
The Op-Amp has many other applications in signal
processing, measurement, and instrumentation etc.