This presentation explains a brief in-depth view of electronic devices and there evolution history. Basic components of devices and their practical applications in this world

2. Electronic Devices &
Circuits

3. About Me
Aatif Saeed
Education
 M.Sc Electronics
 M.Sc Systems Engineering
 MS Project Management
Experience
 16+ Years Teaching
 14+ Years Industry Projects
Email
 aatifsaeed@gmail.com

4. Course Outline
Chapter 1 – 12
Marks Distribution
 Assignments – 10%
 Quizzes – 10%
 Class Participation – 5%
 Mid Term – 25%
 Final – 50%
Final Examination Question Paper
 8 Review Questions out of 12

5. Course Breakup
Chapter # Final Exam
Q. No
Chapter Heading
1 Introduction to Electronics
2 Diodes and Applications
3 Special Purpose Diodes
4 Bipolar JunctionTransistors
5 Transistor Bias Circuits
6 BJT Amplifiers
7 Power Amplifiers
8 Field Effect Transistors (FETs)
9 FET Amplifiers and Switching
Circuits

6. Course Breakup
Chapter # Final Exam
Q. No
Chapter Heading
10 Amplifier Frequency Response
11 Thyristors
12 Operational Amplifiers

7. Text Book
Electronic Devices – 9th Edition
 Thomas L. Floyd

8. Chapter 1
Introduction to Electronics

14. The Start of the Modern
Electronics Era
Bardeen, Shockley, and Brattain
at Bell Labs - Brattain and
Bardeen invented the bipolar
transistor in 1947.
The first germanium bipolar
transistor. Roughly 50 years
later, electronics account for
10% (4 trillion dollars) of the
world GDP.

15. Electronics Milestones
1874 Braun invents the solid-state
rectifier.
1906 DeForest invents triode
vacuum tube.
1907-1927
First radio circuits developed
from diodes and triodes.
1925 Lilienfeld field-effect device
patent filed.
1947 Bardeen and Brattain at Bell
Laboratories invent bipolar
transistors.
1952 Commercial bipolar transistor
production atTexas
Instruments.
1956 Bardeen, Brattain, and
Shockley receive Nobel prize.
1958 Integrated circuits developed
by Kilby and Noyce
1961 First commercial IC from
Fairchild Semiconductor
1963 IEEE formed from merger of
IRE and AIEE
1968 First commercial IC opamp
1970 One transistor DRAM cell
invented by Dennard at IBM.
1971 4004 Intel microprocessor
introduced.
1978 First commercial 1-kilobit
memory.
1974 8080 microprocessor
introduced.
1984 Megabit memory chip
introduced.
2000 Alferov, Kilby, and Kromer
share Nobel prize

16. Evolution of Electronic Devices
Vacuum
Tubes
Discrete
Transistors
SSI and MSI
Integrated
Circuits
VLSI
Surface-Mount
Circuits

17. Introduction to Electronics
Types of Electricity
Two forms of electricity Static and
Produced
Static Electricity is an electrical charge
at rest.
Produced Electricity is produced by
either magnetism, chemicals, light, heat, or
pressure.

18. Introduction to Electronics
The study of electronics can be broken
down into four basic steps:
• Step 1 – Basic Electricity
• Step 2 – Electronic Components
• Step 3 – Electronic Circuits
• Step 4 – Electronic Systems

19. Step 1: Basics of Electricity
• Step 1: Basics of Electricity
• Current – Andre’ Ampere’
• Voltage – AlessandroVolta
• Resistance – George Ohm
• Power – James Watt
Current
Voltage
Power
Resistance
Andre’ Ampere’
Alessandro
Volta
Georg Ohm
James Watt

20. Step 2: Electronic Components
Current
Voltage
Power
Resistance
Components
• Step 2: Electronic Components
Switches and Keyboard
Semiconductors
Transducers
Resistors
Capacitors
Electron Tubes
Magnetic
Nikola Tesla
Thomas Edison

21. Step 3: Electronic Circuits
Current
Votlage
Power
Resistance
Components
Circuits
• Step 3: Electronic Circuits
• Signal Generators and
Timers
• Amplifiers
• Digital Circuits
• Power Supplies
• Detectors and Mixers
• Filters
• Phase-locked Looks
• Converters
• Data Acquisition
• Synthesizers
Charles Wheatstone
Gustav Kirchoff
Robert Noyce

22. Step 4: Electronic Systems
Current
Votlage
Power
Resistance
Components
Circuits
• Step 4: Electronic Systems
• Communications
• Computers
• Consumer
• Industrial
• Test and Measurement
• Biomedical

23. Step 4: Electronic Systems
• Communications Systems
Radio
Telecommunications
Television
Data Communications
Current
Votlage
Power
Resistance
Components
Circuits
Systems
Communications
Heinrich Hertz
Guglielmo Marconi
Lee Deforest
John Baird

24. Step 4: Electronic Systems
Current
Votlage
Power
Resistance
Components
Circuits
Systems
Communication
Computers
• Computers
Data Terminals
Computer Systems
Data Storage
Input/Output Devices
George Boole
John von Neuman
Alan Turing
Charles Babbage

25. Step 4: Electronic Systems
Current
Votlage
Power
Resistance
Components
Circuits
Systems
Communication
Computers
Consumer
• Consumer
Video Equipment
Audio Equipment
Personal
Automobile ElectronicsWilliam Shockley
Chester Carlson
Jack Kilby
Nolan Bushnell

26. Step 4: Electronic Systems
Current
Votlage
Power
Resistance
Components
Circuits
Systems
Communication
Computers
Consumer
Industrial
• Industrial
Manufacturing Equipment
Computer-Aided-Design
and Engineering CAD/CAE
Management
Charles Steinmetz
Werner Von Siemens
James Joule
Carl Gauss

27. Step 4: Electronic Systems
Current
Votlage
Power
Resistance
• Test and Measurement
General Test and
Measurement Equipment
Automated Test Systems
Components
Circuits
Systems
Communication
Computers
Consumer
Industrial
Test and Measurement
Sir Isaac Newton
RAdm Grace Harper
Benjamin Franklin
John Napier

28. Step 4: Electronic Systems
Current
Votlage
Power
Resistance
• Biomedical
Patient Care
Diagnostics
Circuits
Components
Systems
Communication
Computers
Consumer
Industrial
Test and Measurement
Biomedical
Luigi Galvani
Henry Cavendish
Sir John Fleming

29. Chapter 1
Introduction to Electronics

30. The Bohr atom
•The nucleus is positively charged
and has the protons and neutrons.
Electron Proton Neutron
•The atomic number is the
number of protons and
determines the particular
element.
•In the neutral atom, the number
of electrons is equal to the
number of protons.
•Electrons are negatively
charged and in discrete shells.
The Bohr atom is useful for visualizing atomic structure.

31. Shell 3+ Shell 1 Shell 2
A neutral Si atom is shown. There are
4 electrons in the valence shell.
Is Si a conductor, insulator, or
semiconductor?
Semiconductor
The valence shell
The outer shell is called the valence shell. Electrons in
this shell are involved in chemical reactions and they
account for electrical and thermal conductivity in metals.

32. Sodium is highly reactive, and easily
gives up its single valence electron.
For this reason, it is not used in
electrical work.
The valence shell
Metals have one, two or three electrons in the valence
shell. The atom illustrated here is a sodium atom (Na), with
only one electron in its outer shell.
S he ll 3+ S he ll 1 S he ll 2
Sodium atom
Non-metals have either
complete or nearly compete
outer shells, so they make poor
electrical conductors.

33. Electrons and Shells
Energy Levels
 Electrons near the nucleus have less energy
than those in more distant orbits.
 Only discrete (separate and distinct) values of
electron energies exist within atomic
structures.
 In an atom, the orbits are grouped into
energy levels known as Shells.
 A given atom has a fixed number of shells.
Each shell has a fixed maximum number of
electrons.The shells (energy levels) are
designated 1, 2, 3, and so on, with 1 being
closest to the nucleus.

34. Electrons and Shells

35. Electrons and Shells
Max. # of Electrons in Each Shell
Valence Electrons.
 This outermost shell is known as the valence
shell and electrons in this shell are called
valence electrons.

36. Ionization
If a valence electron acquires a sufficient
amount of energy, called ionization
energy, it can actually escape from the
outer shell and the atom’s influence.
The departure of a valence electron
leaves a previously neutral atom with an
excess of positive charge (more protons
than electrons).
The process of losing a valence electron
is known as ionization, and the resulting
positively charged atom is called a positive
ion.

37. The Quantum Model
Each shell or energy level consists of up
to four subshells called orbitals, which
are designated s, p, d, and f.
Orbital s can hold a maximum of two
electrons, orbital p can hold six electrons,
orbital d can hold ten electrons, and
orbital f can hold fourteen electrons.

38. The Quantum Model

39. The Quantum Model

40. Materials Used In Electronics
Insulators
 An insulator is a material that does not
conduct electrical current under normal
conditions.
 Most good insulators are compounds rather
than single-element materials and have very
high resistivities.
 Valence electrons are tightly bound to the
atoms; therefore, there are very few free
electrons in an insulator.
 Examples of insulators are rubber, plastics,
glass, mica, and quartz.

41. Materials Used In Electronics
Conductors
 A conductor is a material that easily
conducts electrical current.
 Most metals are good conductors.
 The best conductors are single-element
materials, such as copper (Cu), silver (Ag),
gold (Au), and aluminum (Al), which are
characterized by atoms with only one valence
electron very loosely bound to the atom.

42. Materials Used In Electronics
Semiconductors
 A semiconductor is a material that is
between conductors and insulators in its
ability to conduct electrical current.
 A semiconductor in its pure (intrinsic) state is
neither a good conductor nor a good
insulator.
 Single-element semiconductors are antimony
(Sb), arsenic (As), astatine (At), boron (B),
polonium (Po), tellurium (Te), silicon (Si), and
germanium (Ge).

43. Materials Used In Electronics
Semiconductors
 Compound semiconductors such as gallium
arsenide, indium phosphide, gallium nitride,
silicon carbide, and silicon germanium are also
commonly used.
 The single-element semiconductors are
characterized by atoms with four valence
electrons.
 Silicon is the most commonly used
semiconductor.

44. Band Gap
Valence shell of an atom represents a
band of energy levels and that the valence
electrons are confined to that band.
When an electron acquires enough
additional energy, it can leave the valence
shell, become a free electron, and exist in
what is known as the conduction band.
The difference in energy between the
valence band and the conduction band is
called an energy gap or band gap.

45. Band Gap

46. Comparison
Semi-Conductor Atom vs Conductor
Atom
 The core includes everything except the
valence electrons.
 The core of the silicon atom has a net charge
of 4 (14 protons 10 electrons)
 The core of the copper atom has a net charge
of 1 (29 protons 28 electrons)

47. Comparison

48. Silicon & Germanium

49. Silicon & Germanium
Both Silicon and Germanium have the
characteristic FourValence electrons.
 The valence electrons in Germanium are in
the fourth shell while those in Silicon are in
the third shell, closer to the nucleus
 Germanium valence electrons are at higher
energy levels than those in silicon
 Germanium more unstable at high
temperatures and results in excessive reverse
current.

50. Covalent Bonds

51. Silicon Crystal

52. Current In Semiconductors
Energy band diagram for an unexcited
atom in a pure (intrinsic) silicon crystal.

53. Conduction Electrons and Holes

54. Conduction Electrons and Holes
Hole
 When an electron jumps to the conduction
band, a vacancy is left in the valence band
within the crystal.
Electron-Hole Pair
 For every electron raised to the conduction
band by external energy, there is one hole left
in the valence band, creating what is called an
electron-hole pair.
Recombination
 occurs when a conduction-band electron
loses energy and falls back into a hole in the
valence band.

55. Conduction Electrons and Holes

56. Electron and Hole Current
 When a voltage is applied across a piece of intrinsic
silicon, the thermally generated free electrons in the
conduction band, which are free to move randomly in
the crystal structure, are now easily attracted toward
the positive end.
 This movement of free electrons is one type of
current in a semiconductive material and is called
electron current.

57. Electron and Hole Current

58. N-type And P-type
Semiconductors
Doping
 Since semiconductors are generally poor
conductors, their conductivity can be
drastically increased by the controlled
addition of impurities to the intrinsic (pure)
semiconductive material.
 This process increases the number of current
carriers (electrons or holes).
 The two categories of impurities are
 n-type and
 p-type.

59. N-Type Semiconductor
To increase the number of conduction-
band electrons in intrinsic silicon,
pentavalent impurity atoms are added.
These are atoms with five valence
electrons such as arsenic (As),
phosphorus (P), bismuth (Bi), and
antimony (Sb).

60. N-Type Semiconductor
Donor Atom

61. Majority and Minority Carriers
 Since most of the current carriers are
electrons, silicon (or germanium) doped with
pentavalent atoms is an n-type semiconductor
(the n stands for the negative charge on an
electron).The electrons are called the
majority carriers in n-type material.
 Although the majority of current carriers in n-
type material are electrons, there are also a
few holes that are created when electron-
hole pairs are thermally generated. These
holes are not produced by the addition of the
pentavalent impurity atoms. Holes in an n-
type material are called minority carriers.

62. P-Type Semiconductor
To increase the number of holes in
intrinsic silicon, trivalent impurity atoms
are added.
These are atoms with three valence
electrons such as boron (B), indium (In),
and gallium (Ga).

63. P-Type Semiconductor
Acceptor Atom

64. The PN Junction
When you take a block of silicon and
dope part of it with a trivalent impurity
and the other part with a pentavalent
impurity, a boundary called the PN
junction is formed between the resulting
p-type and n-type portions.

65. The PN Junction

66. The PN Junction

67. Formation of the Depletion
Region
 When the pn junction is formed, the n region
loses free electrons as they diffuse across the
junction.
 This creates a layer of positive charges
(pentavalent ions) near the junction.As the
electrons move across the junction, the p
region loses holes as the electrons and holes
combine.
 This creates a layer of negative charges
(trivalent ions) near the junction.These two
layers of positive and negative charges form the
depletion region.

68. Energy Diagrams of the PN
Junction

69. Energy Diagrams of the PN
Junction

70. Diodes & Applications
Chapter 2

71. The Diode
A diode is made from a small piece of
semiconductor material, usually silicon, in
which half is doped as a p region and half
is doped as an n region with a pn junction
and depletion region in between.

72. Diode Packages

73. Forward Bias
Forward bias is the condition that
allows current through the pn junction.

74. Forward Bias
Requirements
 Negative side of VBIAS is connected to the n
region of the diode and the positive side is
connected to the p region.
 VBIAS >>> Barrier Potential

75. Effect of Forward Bias on the
Depletion Region
 As more electrons flow into the depletion
region, the number of positive ions is reduced.
 As more holes effectively flow into the
depletion region on the other side of the pn
junction, the number of negative ions is
reduced.
 This reduction in positive and negative ions
during forward bias causes the depletion
region to narrow

76. -cont.

77. Barrier Potential
 When forward bias is applied, the free
electrons are provided with enough energy
from the bias-voltage source to overcome the
barrier potential and cross the depletion
region.
 The energy that the electrons require in
order to pass through the depletion region is
equal to the barrier potential.
 This energy loss results in a voltage drop
across the pn junction equal to the barrier
potential (0.7V)

78. Reverse Bias
Reverse bias is the condition that
essentially prevents current through the
diode.

79. -continued

80. Reverse Current
The extremely small current that exists in
reverse bias after the transition current
dies out is caused by the minority carriers
in the n and p regions that are produced
by thermally generated electron-hole
pairs.

81. V-I Characteristic of a Diode

82. V-I Characteristic of a Diode
Point A corresponds to a zero-bias
condition.
Point B corresponds to where the
forward voltage is less than the barrier
potential of 0.7V.
Point C corresponds to where the
forward voltage approximately equals the
barrier potential.

83. V-I Characteristic for Reverse
Bias

84. The Complete V-I
Characteristic Curve

85. Diode Approximations
The Ideal Diode Model

86. Diode Approximations
The Ideal Diode Model

87. Diode Approximations
 Since the barrier potential and the forward
dynamic resistance are neglected, the diode is
assumed to have a zero voltage across it when
forward-biased
 VF = 0V
 Forward Current
 Reverse Current Neglected

88. Diode Approximation
Practical Diode Model

89. Diode Approximation
Practical Diode Model

90. Diode Approximation
Practical Diode Model
Applying KVL

91. Diode Approximation
Complete Diode Model

92. Diode Approximation
Complete Diode Model

93. Diode Approximation
Complete Diode Model
 Formulas

94. Example 2-1

95. Solution

96. Solution

97. Half-wave Rectifiers
Because of their ability to conduct
current in one direction and block
current in the other direction, diodes are
used in circuits called rectifiers that
convert ac voltage into dc voltage.
Rectifiers are found in all dc power
supplies that operate from an ac voltage
source.

98. Half-wave Rectifiers

99. Half-wave Rectifiers
The rectifier converts the ac input
voltage to a pulsating dc voltage.
The rectifier converts the ac input
voltage to a pulsating dc voltage.
The regulator is a circuit that maintains
a constant dc voltage for variations in the
input line voltage or in the load.

100. Half-Wave Rectifier Operation

101. Half-wave Rectifier
AverageValue of the Half-Wave Output
Voltage
Example 2-2

102. Effect of Potential Barrier

104. Transformer Coupling
It allows the source voltage to be stepped
down as needed.
The ac source is electrically isolated from
the rectifier, thus preventing a shock
hazard in the secondary circuit.

105. Transformer Coupling
Turns Ratio = Nsec / Npri
Turns Ratio > 1  Step Up
Turns Ratio < 1  Step Down
SecondaryVoltage of Transformer
Example 2-4 (Do it by yourself)

106. Full-wave Rectifiers
A full-wave rectifier allows
unidirectional (one-way) current through
the load during the entire 360o of the
input cycle.

107. Full-wave Rectifier
Example 2-5

108. Center-Tapped Full-Wave Rectifier
Operation

109. Operation

110. Effect of theTurns Ratio on the
Output Voltage

111. Effect of theTurns Ratio on the
Output Voltage

112. Bridge Full-wave Rectification

113. Bridge Full-wave Rectification
…
Example 2-7 (Assignment)

114. Peak InverseVoltage
For rectifier applications, peak inverse
voltage (PIV) or peak reverse
voltage (PRV) is the maximum value
of reverse voltage which occurs at
the peak of the input cycle when the
diode is reverse-biased.

115. Power Supply Filters &
Regulators
A power supply filter ideally eliminates
the fluctuations in the output voltage of a
half-wave or full-wave rectifier and
produces a constant-level dc voltage.
A voltage regulator prevents changes in
the filtered dc voltage due to variations in
input voltage or load.

116. Power Supply Filters &
Regulators
The small amount of fluctuation in the
filter output voltage is called Ripple.

117. Capacitor-Input Filter

118. Capacitor-Input Filter

119. Capacitor-Input Filter

120. Capacitor-Input Filter

121. Ripple Voltage

122. Example 2-8

123. Solution

124. Voltage Regulators

125. Percent Regulation
The line regulation specifies how much
change occurs in the output voltage for a
given change in the input voltage.
It is typically defined as a ratio of a change
in output voltage for a corresponding
change in the input voltage expressed as a
percentage.

126. Percent Regulation
The load regulation specifies how much
change occurs in the output voltage over
a certain range of load current values,
usually from minimum current (no load,
NL) to maximum current (full load, FL).

127. Example 2-9

128. Diode Limiters & Clampers
Diode circuits, called limiters or clippers,
are sometimes used to clip off portions of
signal voltages above or below certain
levels.
Another type of diode circuit, called a
clamper, is used to add or restore a dc
level to an electrical signal.

129. Diode Limiters

130. Diode Limiters
Example 2-10 (do it)

131. Biased Limiters

132. Diode Clampers
A Clamper adds a dc level to an ac voltage.
Operation
 During the negative half cycle of the input signal, the
diode conducts and acts like a short circuit.The
output voltageVo  0 volts .
 The capacitor is charged to the peak value of input
voltage Vm. and it behaves like a battery.
 During the positive half of the input signal, the diode
does not conduct and acts as an open circuit.
 Hence the output voltageVo Vm+Vm
 This gives a positively clamped voltage.

133. Diode Clampers
 If the RC time constant is 100 times the period, the
clamping action is excellent.An RC time constant of ten
times the period will have a small amount of distortion at
the ground level due to the charging current.

134. The Diode Datasheet

135. Special Purpose Diodes
Chapter 3

136. The Zener Diode
A Zener diode is a Silicon pn junction
device that is designed for operation in
the reverse-breakdown region.
The breakdown voltage of a Zener diode
is set by carefully controlling the doping
level during manufacture.

137. V-I Characteristics

138. Zener Breakdown
Zener diodes are designed to operate in
reverse breakdown.
Two types of reverse breakdown in a
zener diode are
 avalanche and
 Zener
The avalanche effect, occurs in both
rectifier and Zener diodes at a sufficiently
high reverse voltage.

139. Zener Breakdown
Occurs in a zener diode at low reverse
voltages
A zener diode is heavily doped to reduce
the breakdown voltage.
This causes a very thin depletion region.
As a result, an intense electric field exists
within the depletion region.
Near the zener breakdown voltage (VZ),
the field is intense enough to pull
electrons from their valence bands and
create current.

140. Breakdown Characteristics

141. Breakdown Characteristics
As the reverse voltage (VR) is increased, the
reverse current (IR) remains extremely small up
to the “knee” of the curve.
 The reverse current is also called the zener
current, IZ.
At this point, the breakdown effect begins; the
internal zener resistance, also called zener
impedance (ZZ), begins to decrease as the
reverse current increases rapidly.
From the bottom of the knee, the zener
breakdown voltage (VZ) remains essentially
constant although it increases slightly as the
zener current, IZ, increases.

142. Zener Regulation
A zener diode operating in breakdown
acts as a voltage regulator because it
maintains a nearly constant voltage across
its terminals over a specified range of
reverse-current values.
The zener diode maintains a nearly
constant voltage across its terminals for
values of reverse current ranging from IZK
to IZM.

143. Zener Equivalent Circuits

144. Zener Equivalent Circuits

145. Zener Equivalent Circuits
Zener Impedence

146. Example 3-1

147. Temperature Coefficient
The temperature coefficient specifies the
percent change in zener voltage for each
degree Celsius change in temperature.
where VZ is the nominal zener voltage at
25oC the reference temperature of TC is
the temperature coefficient, and ∆T is the
change in temperature from the reference
temperature.

148. Example 3-2

149. Zener Power Dissipation and
Derating
Power Dissipation
Power Derating

150. Example 3-3

151. Zener Diode Applications
Zener Regulation with aVariable InputVoltage
 Zener diode regulators can provide a
reasonably constant dc level at the output, but
they are not particularly efficient.
 For this reason, they are limited to pplications
that require only low current to the load.

152. Zener Diode Applications

153. Zener Diode Applications
Zener Regulation with aVariable Load

154. Zener Limiter
In addition to voltage regulation
applications, Zener diodes can be used in
ac applications to limit voltage swings to
desired levels.

155. Zener Limiter (a)
 a zener used to limit the positive peakof a
signal voltage to the selected zener voltage.
During the negative alternation, the zener acts
as a forward-biased diode and limits the
negative voltage to -0.7V.

156. Zener Limiter (b)
 When the zener is turned around the
negative peak is limited by zener action and
the positive voltage is limited to +0.7V.

157. Zener Limiter (c)
 Two back-to-back zeners limit both peaks to
the zener voltage.
 During the positive alternation, D12 is
functioning as the zener limiter and D21 is
functioning as a forward-biased diode.
 During the negative alternation, the roles are
reversed.

158. Assignment