Transcript Electronics Engineering - Dronacharya College of Engineering

Text Books:
1. Robert L. Boylestad &Louis Nashelsky “Electronic Devices
and Circuit Theory” ,Tenth Edition, Pearson Education,
2013
2. H S Kalsi, “Electronics Instrumentation,” Third
Edition, TMH Publication 2012
3. George Kennedy, “Electronic Communication System”,
Fifth Edition , TMH Publication, 2012
Unit 1
Semiconductor Diode and its application
 The Physical Principles of Semiconductor
 Diodes
 Diode Circuits
 Zener Diode
 Varactor Diode
 Tunnel Diode
 Liquid Crystal Displays.
Unit 2
Bipolar Junction Transistor
 Transistor Action
 Transistor Configuration
 DC Biasing BJT’s
Field Effect Transistor
MOSFET (Depletion and Enhancement)Type
FET ( Field Effect Transistor)
Few important advantages of FET over conventional Transistors
1.
2.
Unipolar device i. e. operation depends on only one type of
charge carriers (h or e)
Voltage controlled Device (gate voltage controls drain
current)
3.
Very high input impedance (109-1012 )
4.
Source and drain are interchangeable in most Low-frequency
applications
5.
Low Voltage Low Current Operation is possible (Low-power
consumption)
Less Noisy as Compared to BJT
No minority carrier storage (Turn off is faster)
Self limiting device
Very small in size, occupies very small space in ICs
Low voltage low current operation is possible in MOSFETS
Zero temperature drift of out put is possible.
6.
7.
8.
9.
10.
11.
Types of Field Effect Transistors
(The Classification)

FET
JFET
n-Channel JFET
p-Channel JFET
MOSFET (IGFET)
Enhancement
MOSFET
n-Channel
EMOSFET
p-Channel
EMOSFET
Depletion
MOSFET
n-Channel
DMOSFET
p-Channel
DMOSFET
The Junction Field Effect Transistor (JFET)
Figure: n-Channel JFET.
JFET Transfer Curve
This graph shows the value of ID for a given value of VGS
Unit 3
Operational Amplifiers
 Op-Amp Basic
 Practical Op-Amp Circuits
 Differential Amplifier Circuits
 Differential and Common-Mode Operation
Terminals on an Op Amp
Positive power supply
(Positive rail)
Non-inverting
Input terminal
Output terminal
Inverting input
terminal
Negative power supply
(Negative rail)
Op Amp Equivalent Circuit
vd = v2 – v1
v2
A is the open-loop voltage gain
v1
Voltage controlled
voltage source
Typical Op Amp Parameters
Parameter
Variable
Ideal Values
A
Typical
Ranges
105 to 108
Open-Loop
Voltage Gain
Input
Resistance
Ri
105 to 1013 
∞
Output
Resistance
Ro
10 to 100 
0
Supply
Voltage
Vcc/V+
-Vcc/V-
5 to 30 V
-30V to 0V
N/A
N/A
∞
Voltage Transfer Characteristic
Range where
we operate
the op amp as
an amplifier.
vd
Almost Ideal Op Amp
 Ri = ∞ 
 Therefore, i1 = i2 = 0A
 Ro = 0 
 Usually, vd = 0V so v1 = v2
 The op amp forces the voltage at the inverting input terminal
to be equal to the voltage at the noninverting input terminal
if there is some component connecting the output terminal to
the inverting input terminal.
 Rarely is the op amp limited to V- < vo < V+.
 The output voltage is allowed to be as positive or as negative
as needed to force vd = 0V.
Unit 4
 Digital Voltmeter
 Digital Multimeters
 Oscilloscope
Multimeters are designed and mass
produced. The simplest and cheapest
types may include features which are
not likely to use. Digital meters give an
output in numbers, usually on a liquid
crystal display.
Switched
What do meters measure?
 A meter is a measuring instrument. An ammeter
measures current, a voltmeter measures the potential
difference (voltage) between two points, and an
ohmmeter measures resistance. A multimeter
combines these functions, and possibly some
additional ones as well, into a single instrument.
Multimeter
as
a
Ammeter
 Turn Power Off before connecting multimeter
 Break Circuit
 Place multimeter in series with circuit
 Select highest current setting, turn power on, and
work your way down.
 Turn power off
 Disconnect multimeter.
 Reconnect Circuit
Ammeter mode measures current in Amperes. To measure current you need to
power off the circuit, you need to break the circuit so that the ammeter can be
connected in series. All the current flowing in the circuit must pass through the
ammeter. Meters are not supposed to alter the behavior of the circuit, so the
ammeter must have a very LOW resistance. The diagrams below show the
connection of a multimeter to measure current.
Cathode Ray Oscilloscope
(CRO)
Time base
Display
Y-gain
My tie
Channel1
Channel 2
CRO in a Circuit
 It can be used as a
voltmeter by
connecting it across a
component.
 It can be used as an
ammeter by
measuring the voltage
across a resistor of
known value. Then
use I = V/R to get the
current.
CRO
R
CRO
Resistor of known value
(shunt)
R
Reading the CRO 1
Peak-toPeak
voltage
Time Period (ms)
To get the time period you need
to measure this distance and
convert it to time by multiplying
by the time base setting
Reading the CRO 2
 The total height of the wave
from peak to trough is 6.4 cm
 Vpk to pk= 12.8 V
V0 = 6.4 V
6.4
cm
 1 cycle occupies 2.8 cm
 T = 1.40 ms = 1.40  10-3 s
 Frequency = 1  1.40  10-3 s
= 714 Hz
2.8 cm
The time base controls are set at 5 ms/cm
The voltage gain is set at 2 V/cm
Summary
 Mains electricity is always AC.
 In Europe it is at a frequency of 50 Hz.
 AC waveforms have peak voltage and RMS voltage.
 VRMS = 0.7 VPk
 AC waveforms can be studied with a CRO.
Unit 5
Fundamentals of Communication Engineering
 Communication System
 Need of modulation
 Basics of signal representation and analysis
 modulation and demodulation techniques
Communication Systems
 Basic components:
 Transmitter
 Channel or medium
 Receiver
 Noise degrades or interferes with transmitted
information.
Communication Systems
Figure 1: A general model of all communication systems.
Communication Systems
Transmitter
 The transmitter is a collection of electronic
components and circuits that converts the electrical
signal into a signal suitable for transmission over a given
medium.
 Transmitters are made up of oscillators, amplifiers,
tuned circuits and filters, modulators, frequency mixers,
frequency synthesizers, and other circuits.
Communication Systems
Communication Channel
 The communication channel is the medium by which
the electronic signal is sent from one place to another.
 Types of media include




Electrical conductors
Optical media
Free space
System-specific media (e.g., water is the medium for sonar).
Communication Systems
Receivers
 A receiver is a collection of electronic components and
circuits that accepts the transmitted message from the
channel and converts it back into a form understandable
by humans.
 Receivers contain amplifiers, oscillators, mixers, tuned
circuits and filters, and a demodulator or detector that
recovers the original intelligence signal from the
modulated carrier.
Communication Systems
Transceivers
 A transceiver is an electronic unit that incorporates
circuits that both send and receive signals.
 Examples are:
•
•
•
•
•
Telephones
Fax machines
Handheld CB radios
Cell phones
Computer modems
Communication Systems
Attenuation
 Signal attenuation, or degradation, exists in all media
of wireless transmission. It is proportional to the square
of the distance between the transmitter and receiver.
Communication Systems
Noise
 Noise is random, undesirable electronic energy that
enters the communication system via the
communicating medium and interferes with the
transmitted message.
The Electromagnetic Spectrum
 The range of electromagnetic signals encompassing all
frequencies is referred to as the electromagnetic
spectrum.
The Electromagnetic Spectrum
Figure 1-13: The electromagnetic spectrum.
The Electromagnetic Spectrum
Frequency and Wavelength: Frequency
 A signal is located on the frequency spectrum according




to its frequency and wavelength.
Frequency is the number of cycles of a repetitive wave
that occur in a given period of time.
A cycle consists of two voltage polarity reversals, current
reversals, or electromagnetic field oscillations.
Frequency is measured in cycles per second (cps).
The unit of frequency is the hertz (Hz).
The Electromagnetic Spectrum
Frequency and Wavelength: Wavelength
 Wavelength is the distance occupied by one cycle of a
wave and is usually expressed in meters.
 Wavelength is also the distance traveled by an
electromagnetic wave during the time of one cycle.
 The wavelength of a signal is represented by the Greek
letter lambda (λ).
The Electromagnetic Spectrum
Figure 1-15: Frequency and wavelength. (a) One cycle. (b) One wavelength.
The
Electromagnetic
Spectrum
Frequency and Wavelength: Wavelength
Wavelength (λ) = speed of light ÷ frequency
Speed of light = 3 × 108 meters/second
Therefore:
λ = 3 × 108 / f
Example:
What is the wavelength if the frequency is 4MHz?
λ = 3 × 108 / 4 MHz
= 75 meters (m)
The Electromagnetic Spectrum
Frequency Ranges from 30 Hz to 300 GHz
 The electromagnetic spectrum is divided into segments:
Extremely Low Frequencies (ELF)
30–300 Hz.
Voice Frequencies (VF)
300–3000 Hz.
Very Low Frequencies (VLF)
include the higher end of the
human hearing range up to
about 20 kHz.
Low Frequencies (LF)
30–300 kHz.
Medium Frequencies (MF)
300–3000 kHz
AM radio 535–1605 kHz.
The Electromagnetic Spectrum
Frequency Ranges from 30 Hz to 300 GHz
High Frequencies (HF)
3–30 MHz
(short waves; VOA, BBC
broadcasts; government and
military two-way communication;
amateur radio, CB.
Very High Frequencies (VHF)
30–300 MHz
FM radio broadcasting (88–108
MHz), television channels 2–13.
Ultra High Frequencies (UHF)
TV channels 14–67, cellular
phones, military communication.
300–3000 MHz
The Electromagnetic Spectrum
Frequency Ranges from 30 Hz to 300 GHz
Microwaves and Super High
Frequencies (SHF)
1–30 GHz
Satellite communication, radar,
wireless LANs, microwave ovens
Extremely High Frequencies (EHF)
Satellite communication, computer
data, radar
30–300 GHz
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