Comprehensive Analysis of Amplifier Circuits: Types and Applications

This report provides a detailed overview of amplifier circuits, focusing on BJT, FET, and OP-AMP amplifiers. It discusses the characteristics and configurations of each amplifier type, including common base, common emitter, and common collector configurations for BJTs, and common gate, common drain, and common source configurations for FETs. The report also explores the concept of feedback amplifiers, differentiating between positive and negative feedback, and examines the effects of negative feedback on amplifier performance, such as reduced gain and improved stability. Furthermore, it delves into oscillators, specifically Wien bridge oscillators and RC phase-shift oscillators, outlining their applications and operational principles. The document references several sources, providing a well-researched foundation for understanding amplifier circuits and related concepts. Desklib offers a platform to access this and many other solved assignments for students.

Amplifier Circuits

 It is an electronic device
 It is used to increase an amplitude of the
input signal
 It is a two-port network that provides a
high amplitude signal
 There are many applications of an
amplifier such as the audio amplifier,
video amplifier, and increase an amplitude
of an input signal(Karris, 2008).
Amplifiers

 Based on manufacturing amplifiers can be
classified into three categories such as-
 BJT amplifier
 FET amplifier
 OP-AMP amplifier
Types of Amplifiers

 It is a bipolar junction transistor
 It uses both types of charge
carrier such as electron, and
hole
 It can be used as a switch and
amplifier
 There are three terminals in BJT
emitter, base, and collector
 Mode of operation-
 Active region (used as an
amplifier)
 Cut off region (used as a switch)
 Saturation region (used as a
switch)
BJT Amplifier Fig.- BJT Amplifier
(Source: Electric
Engineering, 2014)

 Types of configuration system-
 Common base BJT (CB)
 Common emitter BJT (CE)
 Common collector BJT (CC)
Characteristics of BJT
Amplifier
Characteristic Common
Base
Common
Emitter
Common
Collector
Input Impedance Low Medium High
Output Impedance Very High High Low
Phase Shift 0o 180o 0o
Voltage Gain High Medium Low
Current Gain Low Medium High

 It is a field effect transistor
 It is a unipolar device that
means it uses only electrons as
a charge carrier
 Three terminals gate, source,
and drain
 Types of FET- JFET, and MOSFET
 It is used as an amplifier
because it has large input
impedance and low output
impedance
 There are many applications of
FET such as switch, low noise
amplifier, buffer amplifier,
chopper, and multiplexer.
FET Amplifier Fig.- FET Amplifier
(Source: Electric
Engineering, 2014)

CHARACTERISTICS OF FET AMPLIFIER
FET CONFIGURATION COMMON
GATE
COMMON
DRAIN
(SOURCE
FOLLOWER)
COMMON
SOURCE
Voltage gain High Low Medium
Current gain Low High Medium
Power gain Low Medium High
Input / output phase
relationship
0° 0° 180°
Input resistance Low High Medium
Output resistance High Low Medium
Characteristics of FET
Amplifier

 OP-AMP is defined as operational amplifier
 It is a large gain amplifier which is used to
perform many operations such as amplification,
regulation, and converters (Bhargava, 2013).
 Three terminals- inverting input, non-inverting
input, and an output system
 There are two types of operation perform in op-
amps such as open loop and closed loop
system.
 There are many applications of op-amp such as
a differential amplifier, audio amplifier, filters,
voltage and current regulator, clipper and
clamper circuit (Moore, and Donaghy, 2013).
OP-AMP Amplifier

OP-AMP Amplifier
Fig.- OP-AMP Amplifier Fig.- Characteristics of OP-AMP
Amplifier
(Source: Moore, and Donaghy, 2013).

Characteristics of OP-AMP
(Source: Bhargava, 2013)
Fig.- Characteristics of op-amp

 Feedback means an output of any system is
feedback to the input signal.
 The feedback signal can be in phase (0 degrees)
and out of phase (180 degrees) with an input
signal.
 Types of feedback amplifier-
 Positive (+) feedback amplifier
 Negative (-) feedback amplifier
 In positive (+) feedback system, input signal
and the feedback signal of amplifier are in
phase but in negative feedback, both are out of
phase (Palumbo, and Pennisi, 2008).
Feedback Amplifier

(Source: Verhoeven, et al., 2008).
 In negative feedback amplifier, input signal
and the feedback signal of amplifier are out
of phase (180-degree phase shift)
(Verhoeven, et al., 2008).
Negative Feedback
AmplifierFig.- Negative feedback amplifier