This document provides an overview of basic electronics concepts including definitions, atomic structure, semiconductors, diodes, transistors, and feedback amplifiers. It covers key topics such as the definition of electronics, atomic structure including atoms, electrons and protons, semiconductors including intrinsic and extrinsic types, rectification using diodes, amplification using transistors, and feedback in amplifiers. It also discusses oscillators and provides definitions and examples of different types of oscillators including sinusoidal and relaxation oscillators. The document is intended as teaching material to introduce fundamental electronics topics.

1. Prepared by : Kavisa Tech Solutions

2. Unit –1 Basic Electronics
Introduction
Definition of Electronics
Importance
Rectification
Amplification
Generation
Control
Atomic Structure
Atom
Nucleus
Electron
Proton
Neutron
Session – 1

3. • Charge Of Electron
• Mass of Electron
• Radius of Electron
• Valence Electron
• Free Electron
• Energy Band
• Energy Band Theory
• Valance Band
• Conduction Band
• Forbidden Band
• Classification Of Solid
Session – 1

4. Definition of Electronics : - The branch of engineering which
deals with current conduction through a vacuum or gas or
semiconductor is known as electronics.
Importance : - The electronics devices are capable of performing
the following function :
* Rectification
* Amplification
* Generation
* Control
Atomic Structure
Atom : All the material are composed of very small particles called
atoms.An atom consists of a central nucleus of positive charge
around which small negatively charged particles, called electrons
revolve in different orbits.

5. • Nucleus
• Proton : Positive charge.
• Neutron : No charge.
• Electron : Negative charge.
• Atomic Weight : The sum of proton & neutron.
• Charge of electrons : e=1.6*10-19 coulomb
• Mass of Electron : m = 9.0*10-31 Kg.
• Radius of Electron : r=1.9*10-15 meter.
• Valence Electron : The electrons in the outermost orbit of an atom.
• Free Electron : The valence electrons which are very loosely
attached to the nucleus.
• Energy Band : The range of energies possessed by an electron in
solid.

6. Energy Band Theory
Valance Band : In valance energy band, there are valance electrons. This band
may be partially or completely filled with electrons. This band is never empty. In
this band electrons are not capable of gaining energy from external electric field.
Therefore, the electrons in this band do not contribute to the electric current.
Conduction Band : In conduction energy band, electrons are rarely present. This
band is either empty or partially filled with electrons. In this band, the electrons
can gain energy from external electric field. Electrons in this band contribute to
the electric current
Forbidden Gap : In forbidden energy gap, electrons are not found in this band.
This band is completely empty. The minimum energy required for shifting
electrons from valance band to conduction band is called as band gap (Eg).

7. Classification Of Solid
•Insulator
e.g. Wood, Glass etc
•Conductor
e.g. Copper, Aluminium etc.
•Semiconductor
e.g. Silicon,Germanium etc.

8. Session – 2
Semiconductor(SC)
Types of Semiconductor
Intrinsic Semiconductor
Extrinsic Semiconductor
Types of Extrinsic SC
P type SC
N type SC
PN Junction
PN Junction Under Forward Bias
PN Junction Under Reverse Bias
Formation Of Depletion Layer

9. Semiconductor Diode
Diode Characteristics
Diode Current Equation
Break DownVoltage
KneeVoltage
Peak InverseVoltage
Session – 2

10. • Semiconductor (SC)
A substance which has resistivity (10-4 to 0.5  meter) between
conductors and insulators.
Types of Semiconductor
Intrinsic Semiconductor : A pure sc which is free of every impurity is
called intrinsic sc. The electrical conductivity of a pure sc is
totally governed by the number of electrons excited from
valance band to the conduction band and is called intrinsic
conductivity.
Germanium and silicon are the important examples of intrinsic
sc which are widely used in electronic and transistor
manufacturing. The electronic configuration of silicon and
Germanium are as follows:
Silicon(14), 1s2 2s2 2p6 3s2 3s2
Germanium(32), 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p2

11. Extrinsic Semiconductor :
A doped semiconductor or a semiconductor with suitable impurity atoms added
to it, is called extrinsic semiconductor. Extrinsic semiconductors are of two
types:
N-type Semiconductors P-type Semiconductor
Electro
n

12. N-Type Semiconductor
When a small amount of pentavalent impurity is added to a pure
semiconductor, say arsenic or phosphorus or antimony which have five
valence electrons.
Electron

13. P-type semiconductor
When a small amount of trivalent impurity is added to a pure
semiconductor, say Indium (In) or boron (B) Aluminums (Al) which have
three valence electrons.

14. • PN Junction
Contact surface of P-type SC and N-type SC.
• Formation Of Depletion Layer

15. • PN Junction Under Forward Bias
A p-n junction is said to be forward biased if the positive
terminal of the external battery B is connected to p-side and the
negative terminal to the n-side of p-n junction.

16. • PN Junction Under Reverse Bias
A p-n junction is said to be reverse biased if the positive
terminal of the external battery B is connected to the n-side
and the negative terminal to p-side of the p-n junction.

17. Semiconductor Diode
Diode Characteristics
Forward
Revers
e
Break
Down
V
I

18. • Diode Current Equation
I=Io(ev/n VT -1)
where, I = Diode current
Io = Reverse Saturation Current
v= Applied voltage
VT = Voltage equivalent of temp (T/11600)
n = 1for Ge & 2 for Si at t=27oC or 300oK( Room Temp.)
• Break Down Voltage : It is the reverse voltage at which PN junction
breaks down with sudden rise in reverse current.
• Knee Voltage : It is forward voltage at which the current through
the junction starts to increase rapidly.
• Peak Inverse Voltage : It is the maximum reverse voltage that can
be applied the PN-junction without damage to the junction.

19. Session – 3
Crystal Diode Rectifier
Half Wave Rectifier
Efficiency
Ripple Factor
Full Wave Rectifier
Efficiency
Ripple Factor
Comparison Of Rectifier

20. • Crystal Diode Rectifier
A PN-junction or a crystal diode is used as a rectifier to
change alternating current to direct current.
• Efficiency : The ratio of d.c power output to the applied
input a.c. power.
d.c. power output
 =
Input a.c power
• Ripple Factor : The ratio of r.m.s value of a.c. components to
the d.c. component in the rectifier output.
d.c. power output
 =
Input a.c power
• Half Wave Rectifier
A.C. to be rectified is connected to the primary P1 P2 for a
step-down transformer. S1 S2 is the secondary coil of the same
transformer S1 is connected to the portion p of the p-n
junction. S2 is connected to the portion n through load
resistance R. Output is taken across the load resistance R fig.

22. During the positive half cycle of the input A.C., suppose P1 is negative
and P2 is positive. On account of induction, S1 becomes positive. S2,
become negative. The p-n junction is forward biased. The forward
current flows in the direction shown by arrow heads. Thus we get
output across-load.
During the positive half cycle of the input A.C., P1 is positive and P2 is
negative. On account of mutual induction S become negative and S1
become negative. S2 become positive. The p-n junction is reverse biased.
It offers high resistance and hence there is no flow of current and thus
no output across load. The process is repeated. In the output, we have
current corresponding to one half is missing. The output voltage is of the
type is shown in fig.
That is why the process is called half wave rectification. It is not of much
use. The output signal is available in bursts and not continuously.
• Efficiency of HWR : 40.6%.
• Ripple Factor of HWR : 121%.

23. • Center Tape Full Wave of Rectifier
For full wave rectification, we have to use two p-n junctions. The
arrangement is show in fig
INPUT
VOLTAGE
OUTPUT
VOLTAGE

24. During the positive half of the input A.C., the upper p-n junction
diode is forward biased as show in fig, and the lower p-n junction
diode is reversed biased. The forward current flows on account of
majority carriers of upper p-n junction diode in the direction
shown.
During the negative half cycle of input A.C. the upper p-n junction
diode is reverse biased, and the lower p-n junction diode is forward
biased, fig. The forward current flows on account of majority
carriers of lower p-n junction diode. We observe that during both
the halves, current through R flows in the same direction. The input
and output waveforms are show in fig. The output signal voltage is
unidirectional having ripples contents. i.e. D.C. components and
A.C. components. It can be made D.C. by filtering is through a filter
circuit, before it can be put to any value.
Efficiency of FWR : 81.2%
Ripple Factor of FWR : 48%.

25. Comparison of Rectifier
S.No. Particular Half-Wave Center Tape Bridge
1 No. of Diode 1 2 4
2 Transformer Necessary No Yes No
3 Max. Efficiency 40.6% 81.2% 81.2%
4 Ripple Factor 1.21 0.48 0.48
5 Output Frequency fin 2fin 2fin
6 Peak InverseVoltage Vm 2Vm Vm

26. Zener Diode
Zener Diode asVoltage Regulator
Varactor Diode
Power Supply
Session – 4

27. • Zener Diode
1. Properly doped crystal diode which has a sharp breakdown voltage.
2. A zener diode always reverse connected.
3. A zener diode has sharp breakdown voltage, called zener voltage.
Zener diode as voltage
Stabiliser

28. Varactor Diode
Arrow
Head
Bar
Power Supply
Full Wave
Rectifier
Capacitor
Filter
Voltage
Regulator

29. Unit – 2 Bipolar Junction & Field Effect Transistor
Introduction
Bipolar JunctionTransistor
Terminal Of BJT
o Emitter
o Base
o Collector
Types Of BJT
o PNPTransistor
o NPNTransistor
Transistor as an Amplifier
Session – 5

30. • Bipolar Junction Transistor (BJT)
A transistor consist of two pn junctions formed by sandwiching either
p-type or n-type semiconductor between a pair of opposite types.
• Terminal of BJT
•Emitter : The section of on side that supplies charge carries is called emitter.
The emitter is always forward bias.
•Collector : The section of other side that collects the charges is called
collector. The collector is always reverse bias.
•Base : The middle section which form two pn-junction between the emitter &
collector.

31. PNP Transistor
The emitter base junction is forward biased. It means the positive pole of
emitter base battery VBB is connected to emitter, and its negative pole
to the base. Collector base junction is reverse biased i.e. the negative
pole of the collector base battery VCC is connected to collector and its
positive pole to the base.

32. • NPN Transistor
In this case also, the emitter base junction is forward biased i.e., the
positive pole of emitter base battery VBB is connected to base and its
negative pole to emitter.

33. • Transistor As an amplifier

34. • Common Base Configuration
• Input Characteristics
• Output Characteristics
• Amplification Factor
• Common Emitter Configuration
• Input Characteristics
• Output Characteristics
• Amplification Factor
• Transistor Biasing
Session – 6

35. • Common Base Configuration
• Fig.
• Input Characteristics

36. • Output Characteristics
• Amplification Factor

37. • Common Emitter Configuration
• Input Characteristics

38. • Output Characteristics
• Amplification Factor

39. • Transistor Biasing
• fig.
0
IC
VCE
A
(mA
)

40. Field Effect Transistor
Terminal Of FET
Source
Base
Drain
Channel
Types Of FET
Junction Field Effect Transistor(JFET)
Metal Oxide Semiconductor Field Effect Transistor(MOSFET)
N Channel JFET
P Channel JFET
Difference Between BJT & FET
Session – 7

41. • Field Effect Transistor
It is a three terminal unipolar solid state device in which
current controlled by an electric field.
• Terminal Of FET
• Source : It is the terminal through which majority carriers enter the
bar.
• Drain :It is the terminal through which majority carriers leaves the
bar.
• Gate : These are two internally connected heavily doped impurity
region.
• Channel : It is the space between two gates through which form
source & drain.
• Types of FET
• Junction Field Effect Transistor(JFET)
• Metal Oxide Semiconductor Field Effect Transistor(MOSFET)

42. P-CHANNEL
G
-
D +VD
D
S
G
+
D -VD D
S
JUNCTION
FET
(JFET)
METAL-OXIDE SEMICONDUCTOR
FET (MOSFET )
FET
DE MOSFET E-ONLY MOSFET
N-
CHANNEL
P-
CHANNEL
N-CHANNEL N-CHANNELP-CHANNEL
G
D +VD D
S -
G
D -VD D
S + S
+
G
+
D +VD
D
S
-
G
-
D -VD
D

43. NN
PP
N Channel JFET
P Channel JFET S
D
N-CHANNEL
G G
D
S
S
D
P-CHANNEL
G
D
G
S

44. • Output Characteristics Of JFET
Difference Between BJT & FET
1. FET operation depends upon the flow of majority carriers only. It is
therefore a unipolar device where as a BJT operation depends upon the
flow of both majority and minority carriers.
2. FET is simpler to fabricate and occupies less space in integrated form.
3. FET exhibit a high input resistance, typically many Mega ohms.
4. FET is noisy than BJT.
VGS=-
4V=VPO
4
V
0
IDSS
ID
VDS
VB1 2 3
VPO
VBO

45. • Metal Oxide Semiconductor FET
• Enhancement – only MOSFET

46. • Depletion - Enhancement MOSFET

47. Unit – 3 Feedback Amplifier & Oscillator
 Introduction
 Feedback
 Positive Feedback
 Negative Feedback
 Gain of Amplifier without Feedback
 Gain of Amplifier with Feedback
 Advantage of Negative Feedback
 Types Of Negative Feedback
 Voltage Series Feedback
 Voltage Shunt Feedback
 Current Series Feedback
 Current Shunt Feedback
Session – 9

48. • Feedback
Feedback is the process of feeding back a fraction of the output signal into input
signal.
• Positive Feedback : If the feed back voltage of current is so
applied as to increase the input voltage.
• Negative Feedback : If the feedback voltage or current is do
applied as to reduce the amplifier input.
The gain of amplifier without feedback
VS Vo
AV
AV =VS /Vo
+
VS
AVf
Vo
Feedback Network
Vo
Vin=VS+Vf
The gain of amplifier with feedback AVf =AV / 1-  AV

49. • Advantage of Negative Feedback
• Gain Stability
• Reduce Non-Linear Distortion
• Improve Frequency Response
• Increases Circuit Stability
• Increases Input Impedance and Decrease Output Impedance
• Types Of Negative Feedback
• Voltage Series Feedback
Amplifier
Gain
AV
Feedback
Loop, 
RLVS
Vf

50. +
VS
_
B
+
_
VBE
+VCC
RL
+
VO
_
+
VS
_
If
+VCC
RC
+
VO
_
C
E
Vi
RS
B

51. • Voltage Shunt Feedback
Current Series Feedback
Current Shunt Feedback
Amplifier
Gain
AV
Feedback
Loop, 
IS
If
RL
V0

52. Oscillator
Difference between Amplifier and An
Oscillator
Types of Oscillator
Sinusoidal Oscillator
Relaxation Oscillator
Types of Sinusoidal Oscillator
Damped Oscillator
Undamped Oscillator
Barkhausen criteria for Oscillator
Generation of Sinusoidal wave by a tuned LC
circuit
Session – 10

53. • Oscillator
It is a circuit which converts electric energy at d.c.(zero frequency) to electric
energy at frequency varying from a few Hz to GHz.
• Difference between Amplifier and An Oscillator
Types of Oscillator
Sinusoidal Oscillator
SinWave Form
Relaxation Oscillator
Square or Rectangle or SawtoothWave Form
Amplifier Oscillator
Input Signal
D.C. Power
Input
Output Signal Output Signal
D.C. Power
Input

54. Types of Sinusoidal Oscillator
• Damped Oscillator : The electrical Oscillations whose amplitude goes
on decreasing with time.
• Undamped Oscillator : The electrical oscillations whose amplitude
remain constant with time.

55. • Barkhausen criteria for Oscillator
An amplifier can suitably modified so that it can behave as an
oscillator. The feedback network should be arranged to feedback from
the output sufficient portion so as to provide the necessary input drive.
Then no external drive would be necessary.
Amplifier
Frequency
Selection
Automatic
Amplitude
Control
Feedback
Outpu
t

56. • Classification of Oscillators According to Frequency
Class Of Oscillator Range of Frequency
Audio Frequency a few Hz To 20Khz.
Radio Frequency 20Khz To 30Mhz.
Very High Frequency 30Mhz To 300Mhz.
Ultra High Frequency 300Mhz to 3Ghz.
Microwave 3Ghz and above.
•Generation of Sinusoidal wave by a tuned LC circuit

57. Types of Oscillator
Colpitts Oscillator
Hartely’s Oscillator
RC Phase Shift Oscillator
Wien Bridge Oscillator
Crystal Oscillator
Session – 11

58. • Collpitts Oscillator
CC
C1
RE
+VCC
CC
CE
C2
Out Put

59. • The Hartley Oscillator
CB
RE
+VCC
CC
CE
L2L1
C

60. • RC Phase Shift Oscillator
C C C
R R ViVf R1
R2
RC
RE
V0
+VCC
R3
vi
c C1 C2
C3
R
V0
Vi R1 R2
V0

61. • The Wien Bridge Oscillator
V0
+VCC

62. • Crystal Oscillator
CB
RE
+VCC
CC
CE
RFC
C1
C2
R2
R1
CRYSTAL

63.  Resonant Circuit
 Series Resonant Circuit
 Parallel Resonant Circuit
 Tuned Amplifier
 Single Tuned Amplifier
 Double Tuned Amplifier
Session – 12

64. • Resonant Circuit
• Series Resonant Circuit
Parallel Resonant Circuit
L
R
C
L
R
~ C
~

65. Tuned Amplifier
• Single Tuned Amplifier
L
CE
Vo
Vin
R1
CC
R3R2
RFC
~

66. • Double Tuned Amplifier
Vo
LP
CEVin
R1
CC
R3R2
CP
~
CS
LS

67. Unit – 4 Modulation
Introduction
Need of Modulation
Types of Modulation
 Amplitude Modulation
 Frequency Modulation
 Phase Modulation
Amplitude Modulation
 Generation of Amplitude Modulation
 Detection Of Amplitude Modulation
Session – 13

68. • Modulation
The process of superimposing the audio signal over the carrier
signal.
• Need for Modulation
Audio
Amplifier
Amplifier
RF Oscillator
(Carrier)
Power
Amplifier
RF Carrier
Audio Signal
Antenna

69. • Amplitude Modulation
When the amplitude of high frequency carrier wave is
changed in accordance with the intensity of the signal

70. • Generation Of AM wave
CE
RF Carrier
Input
R1
CC
R3R2
Audio Input
T1
CC
L
C
Modulated
Output
T2

71. • Demodulation
The process of recovering the audio signal from the
modulated wave.
• Detection Of AM
OUTPUT
Vs
+
-

72. Frequency Modulation
• Generation of Frequency Modulation
• Detection of Frequency Modulation
Basis of Digital Modulation
Types of Digital Modulation
• Pulse Amplitude Modulation
• Pulse Width Modulation
• Pulse Position Modulation
• Pulse Code Modulation
Session – 14

73. • Frequency Modulation
when the frequency of carrier wave is changed in accordance the
intensity of the signal.
• Generation of FM
Modulating
Signal
L C CV
Detection of FM
1. Conversion of frequency changes in the modulated carrier
into corresponding amplitude changes.
2. Rectification of the modulated signal.
3. Elimination of the carrier component.

74. • Basis of Digital Modulation
In digital modulation, the continuos waveforms are
sampled at regular intervals.
• Types of Digital Modulation
• Pulse Amplitude Modulation
• Pulse Width Modulation
• Pulse Position Modulation
• Pulse Code Modulation

75. Unit – 5 Liner ICs
• Introduction
• Operational Amplifier
• Block Diagram of an IC OPAMP
• Ideal Characteristics of an OPAMP
• Basic OPAMP and Its Equivalent
• Virtual Ground Concept
• Application of OPAMP
• Constant Gain Multiplier
• Non Inverting Amplifier
• Voltage Follower
Session – 15

76. • Operational Amplifier
• Basic OPAMP and Its Equivalent
+VCC
-VCC
Inverting input
Non inverting input
-
OPAMP
+
Output
~
-
-
V2
V1 +
2
1 Iin
+
Vi Ri
VoAvVi

77. • Block Diagram of an IC OPAMP
DIFF AMP DIFF AMP
EMITER
FOLLOWER
LEVEL TRANSLATOR
& OUTPUT DRINER
AV 1 AV 2
AV 3=1 AV 4
+
VI
_
+
V2
-
+
V3
-
+
V4
-
R1
+
V0
-

78. • Ideal Characteristics of an OPAMP
The ideal OPAMP has the following characteristics :
Input resistance Ri = Infinite
Output resistance Ro = 0
Voltage Gain Av = Infinite
Bandwidth = Infinite
Perfect Balance : Vo=0 when vi=0
Characteristics do not drift with temperature

79. • Virtual Ground Concept
+
V0
-
OPAMP
+
Vi
-Vs
+
-
+
Vo
-
Rf
Iin
R
I I
Vs
+
-
Iin= 0
VG

80. • Application of OPAMP
• Constant Gain Multiplier
OPAMP
+
Vi
-Vs
+
-
+
Vo
-
Rf
Iin
RRf
Vo= VS
R

81. Non-Inverting Amplifier
Rf
Iin
R
OPAMP
+
Vi
- +
Vo
-
+
VS
-
Rf +R
Vo= VS
R

82. Voltage Follower
-
OPAMP
+ +
Vo
-
+
VS
-
V o=VS

83. Summing Amplifier
Rf
Vo= VS
R
-
OPAMP
+ +
Vo
-
Rf
R1
R2
R3
V1
V2
V3

84. Subtractor Amplifier
-
OPAMP
+ +
Vo
-
Rf
R1
R2
V1
V2
R3

85. Integrator
+
Vo
-
-
OPAMP
+Vs
+
-
C
R

86. Differentiator
+
Vo
-
-
OPAMP
+Vs
+
-
R
C

87. • Timer (IC 555)
8
5
1 2
6
4
7
3R Q
_
F/F
S
O/P
Stage
VCC
(2/3 )VCC
(1/3 )VCC
Q
2
Q
1
VCC
Discharge
Threshold
ControlVoltage
Ground
Trigger Input
Output
Reset
1
2
3
4
8
7
6
5

88. • Application of Timer
• Multivibrator
In digital systems a rectangular waveform is most desirable. The generators of rectangular waveform are referred to as multivibrators.
There are Two types of multivibrators:
a. Astable (or free running) multivibrators
b. Monostable multivibrator (or one shot)

89. • Principles of Microphone and Loudspeakers
A microphone is a device that converts sound energy into electrical
energy.
A loudspeakers is a device that convert electrical energy in to sound
energy.