ELE 112
Electronic Circuits
Dr. Ahmed Nader
Professor
Faculty of Engineering, Galala University
Fall 2023
1
Course Details
Instructor: Dr. Ahmed Nader
Email: ahmed.rizk@gu.edu.eg
Lecture: Monday 9:00pm – 10:40pm  Engineering (N224)
Tutorial: Wednesday 9:00am – 12:20pm  Engineering (N143)
Lab: Wednesday 1:10pm – 4:30pm  Circuits Lab (N325)
Prerequisite: ELE111 (Electrical Circuits)
References:
 Albert Malvino, David J. Bates, Patrick E. Hoppe, “Electronic
Principles”, McGraw Hill, 2021 (9th Edition)  Textbook
 Behzad Razavi, “Fundamentals of Microelectronics”, Wiley, 2021
Office hours: (2nd floor at Faculty of Engineering, Room N201):
Monday
11:00am – 1:00pm
2
Biography
3
Schedule
4
Course Learning Outcomes
• Identify basic physical principles controlling
semiconductor devices
• Understand the diode theory and I/V characteristics
• Analyze circuits with diodes and Zener diodes
• Describe the structure of the different transistors (BJT, ..)
• Develop small-signal model for different transistors
• Recognize different BJT single-stage amplifier topologies
• Solve DC / AC analysis of simple electronic circuits
• Determine voltage gain, input / output resistance of
single-stage amplifiers
• Perform laboratory experiments to characterize electronic
5
circuits
Syllabus
Week
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Lecture Topic
Semiconductors
Diode Theory
Diode Circuits
Diode Applications
Special Diodes
BJT Fundamentals
BJT Biasing
Midterm Exam
BJT Single-Stage Amplifiers
BJT Multi-Stage Amplifiers
JFET
MOSFET Fundamentals
MOSFET Amplifiers
Review
Lab Exam
Book
Chapter 2
Chapter 3
Chapter 4
Chapter 4
Chapter 5
Chapter 6
Chapter 7
Chapter 8
Chapter 9
Chapter 11
Chapter 12
Chapter 12
Sheet
Lab
Grading
Final Exam
Term Work
Quizzes
Lab Reports
Mid-Term Exam
Lab Exam
Project
40
60
10
10
20
10
10
 Dedicate at least 10 hours per week for this class.
 75% attendance is required.
 Final Exam: The final exam will be a comprehensive exam
given during finals week and will cover all of the studied
material.
 There will be also a Lab Exam during the final week of
classes.
 Late reports receive no credit.
7
Code of Conduct
8
Instructor’s Expectations of Students
 As a student in this course, you are expected to:
–
–
–
–
–
–
Conform with GU’s academic integrity policy
Be aware of and follow the course schedule
Study the session material (textbook, etc.)
Complete the reading assignments and the problem assignments
Complete the lab experiments
Recognize your own weak areas and correct these using additional self
study (e.g., working additional problems)
– Seek help when needed
– Perform the assessments
– Provide feedback about the course
Because learning changes everything. ®
Chapter 2
Semiconductors
Electronic Principles
Ninth Edition
Albert Malvino, David J. Bates, Patrick E. Hoppe
© 2021 McGraw-Hill. All rights reserved. Authorized only for instructor use in the classroom.
No reproduction or further distribution permitted without the prior written consent of McGraw-Hill.
Topics Covered in Chapter 2
•
•
•
•
Conductors.
Semiconductors.
Silicon Crystals.
Doping a
Semiconductor.
• Two Types of
Semiconductors.
© McGraw-Hill
•
•
•
•
•
•
The Unbiased Diode.
Forward Bias.
Reverse Bias.
Breakdown.
Energy Levels.
Barrier Potential and
Temperature.
11
Conductors
1
Material that allows current to easily flow.
Examples: Copper, Silver, Gold.
The Atom is the basic building
block of all matter. Comprised of:
• Nucleus (Protons & Neutrons)
Copper Atom
• Electrons
© McGraw-Hill
12
Core
• Comprised of the nucleus and inner orbits.
• The valence or outer orbit controls the
electrical properties.
• The attraction between the core and valence
electron is weak.
• An outside force easily dislodges (moves) a
valence electron from an atom.
• An atom tends to have 8 electrons in the
valence orbit  stable and non-reactive
© McGraw-Hill
13
Conductivity
Valence Saturation
Valence Electrons
Access the text alternative for slide images.
© McGraw-Hill
14
Semiconductors
• Silicon, Germanium.
• 4 electrons in the outer
shell.
• Silicon is most abundant
element after ….
• Silicon Germanium (SiGe) is a semiconductor technology
made for wireless applications. It offers the high-speed,
high-frequency performance needed for wireless
systems, and it provides the potential for integrating
analog, RF, and digital functions on a single IC
Access the text alternative for slide images.
© McGraw-Hill
15
Core Diagrams
Copper
Silicon
1 valence electron
4 valence electrons
• An atom losing a valence electron will become
positively charged with net charge +1 (positive ion)
• An atom gaining a valence electron will become
negatively charged with net charge -1 (negative ion)
Access the text alternative for slide images.
© McGraw-Hill
16
Electronics Industry
•
•
•
•
•
Electronics industry has an estimated size of ~$4,000 B with an expected
6% CAGR (compound annual growth rate)
The market size, measured by revenue, of the Iron & Steel Manufacturing
industry is $1,500 B (2021) with 2.9% CAGR
The market size of Global Automotive industry is $3,000 B (2021) with 7%
CAGR
The Personal Computer (PC) boom of the last century has become
Smartphone, Notebook and Tablet explosion in new millennium.
Microcontrollers, Microprocessors, and Digital Signal Processors (DSP)
have been the center of the industrial revolution.
© McGraw-Hill
Semiconductor Industry
• Semiconductors is the heart of the electronics industry with
revenues that reached $500 B (2021)
• Largest semiconductor companies are: Intel (more than
100,000 employees in 40 countries) with $75 billion
revenue in 2020. Samsung Electronics ranked second.
TSMC, Hynix, Micron, Broadcom, Qualcomm, Texas
Instruments, Nvidia, and Toshiba rounding out the top 10.
IC Export
© McGraw-Hill
Electronics Design Life Cycle
Circuit
simulation
Layout
Testing &
Measurements
© McGraw-Hill
Fabrication
Packaging
Electronics Design
Integrated Circuit (IC) versus Printed Circuit Board (PCB)
o Electronic network fabricated in a single piece of a semiconductor material is called
Integrated Circuit
© McGraw-Hill
History
 1958: First integrated circuit
o Integrated oscillator (R,C, 2 transistors)
o Built by Jack Kilby (Nobel Laureate) at Texas Instruments
o Robert Noyce (Fairchild) is considered as an inventor
 1960’s TTL logic (Bipolar)
 1970’s CMOS processes for low idle power
Kilby First IC
1958
Intel 1101
256-bit SRAM
© McGraw-Hill
Intel 4004 4-bit microprocessor (1971)
10μm technology (2300 MOSFET in 4mmx3mm)
108 kHz clock frequency
Integrated Circuits
Moore’s Law: Number of Transistors double every 1.5 - 2 years
Very Large-scale integration (VLSI): 100,000s of logic gates
© McGraw-Hill
Technology Scaling
Intel Pentium 4 microprocessor (2000)
0.18μm technology
50 million transistors
1.6 GHz clock frequency
© McGraw-Hill
Clean Room
o
o
o
o
o
Small contamination can damage the chip during fabrication.
Fabrication facility (Foundry) has controlled environment.
Particle free walls, furniture, and accessories must be used.
Airflow through 0.3 microns filters.
Fabrication is very expensive. It is done in large volumes and takes about
12-16 weeks for chips to come back.
© McGraw-Hill
From Sand to Integrated Circuit
o A silicon ingot is grown with a very high quality (a single-crystal with very small
number of defects/impurities).
o A seed of crystalline silicon is immersed in molten silicon and gradually pulled out
while rotating. (Czochalski method)
o Silicon is a popular semiconductor (others are Germanium, Galium Arsenide)
material due to its low cost
Slicing
Chips
(Dies)
Dicing
© McGraw-Hill
Slicing
Wafer
Packaging
Package
Wi-Fi Receiver
Bond
Wires
© McGraw-Hill
Summary: IC Design
 Small Area (Scaling)
 More Functionality (Lower cost)
 Good Matching
- Difference between two identical devices on the
same chip that is created due to manufacturing
process
 Poor Accuracy (PVT variations)
– Small dimensions limited by lithography
– Doping levels (𝑽𝑻𝑯 , 𝝁)
– 𝑪𝒐𝒙 (𝒅𝒆𝒑𝒆𝒏𝒅 𝒐𝒏 𝒕𝒐𝒙 )
– Lateral diffusion (𝑪𝒈𝒅 )
© McGraw-Hill
Silicon Crystals
covalent bond
 Silicon atoms arrange themselves into a crystal (solid).
 A silicon atom shares its electrons with four neighboring
atoms to have eight electrons in its valence orbit.
 Shared electron is being pulled in opposite directions,
the electron becomes a bond between the opposite cores.
This chemical bond is called a covalent bond.
 A silicon crystal is almost an insulator at room temp.
© McGraw-Hill
28
Holes
•
Vibrations happen for ambient
temperatures higher than absolute zero
(0°K = -273°C)
•
Thermal energy creates free electrons
and equal number of holes.
•
The departure of the electron creates a
vacancy in the valence orbit called a
hole.
•
This hole behaves like a positive charge
because the loss of the electron
produces a positive ion.
•
Main difference between conductors
and semiconductors.
© McGraw-Hill
Conduction Band
29
Free Electron Density
Eg = 1.12 eV = 1.792 × 10−19 J
 Eg
ni  5.2 10 T exp
electrons / cm3
2kT
ni (T  3000 K )  1.08  1010 electrons / cm3
15
3/ 2
ni (T  6000 K )  1.54  1015 electrons / cm3
• At temperatures > absolute zero (-2730C)  heat energy
 vibrations  some electrons can break covalent bond.
• Eg (bandgap energy): how much effort is needed to break
off an electron from its covalent bond  conduction band
• There exists an exponential relationship between the freeelectron density and bandgap energy.
• Silicon has 5 × 1022 atoms / cm3
© McGraw-Hill
30
Recombination
• The hole will attract and capture any
electron in the immediate vicinity.
• Recombination  merging of a
free electrons falling into a hole.
• Recombination takes place every
few nanoseconds to several
microseconds (crystal purity, …).
• The time between creation and
recombination of a free electron and
a hole is called the lifetime.
© McGraw-Hill
31
Intrinsic Semiconductors
• Pure semiconductor. A silicon crystal is an intrinsic
semiconductor if every atom is a silicon atom.
• At room temperature, a silicon crystal acts like an
insulator because it has only a few free electrons and
holes (charge carriers) produced by thermal energy.
• Electrons move in the conduction band & holes move
in the valence band.
Electrons
Current
Holes
© McGraw-Hill
32
Hole Movement
© McGraw-Hill
33
Extrinsic Semiconductors
 A dopant (impurity) has been added to the silicon
to alter its electrical conductivity.
 The first step is to melt a pure silicon crystal. This
breaks the covalent bonds and changes the silicon
from solid to a liquid.
 To increase the number of free electrons,
pentavalent atoms are added to the molten silicon.
 To increase the number of free holes, trivalent
atoms are added to the molten silicon.
© McGraw-Hill
34
Pentavalent Dopant
• Pentavalent atoms have five electrons
in the valence orbit.
Examples: phosphorus and arsenic.
• These materials will donate an extra
electron to the silicon crystal, they are
often referred to as donor impurities.
• N-Type Silicon.
• Majority carriers are electrons.
• Minority carriers are holes.
© McGraw-Hill
35
Trivalent Dopant
• Trivalent atoms have three electrons in
the valence orbit.
Examples: boron and gallium.
• These materials will accept an
electron to the silicon crystal, they
are often referred to as acceptor
impurities.
• P-Type Silicon.
• Majority carriers are holes.
• Minority carriers are electrons.
© McGraw-Hill
36
Intrinsic and Extrinsic
Semiconductors
Majority Carriers (P):
p  NA
2
n
Minority Carriers (P): n  i
NA
Majority Carriers (N):
n  ND
2
Minority Carriers (N): p  ni
ND
𝑛 × 𝑝 = 𝑛𝑖 2
• The product of electron and hole densities is
ALWAYS equal to the square of intrinsic
electron density regardless of doping levels.
© McGraw-Hill
37
Electron & Hole Densities
© McGraw-Hill
38
Energy Bands
Energy
Gap
• The holes remain in the valence band, but the free
electrons go to the next-higher energy band
(conduction band).
• In Ge, the energy gap is small  Large leakage 
© McGraw-Hill
39
Video
© McGraw-Hill
40
PN Junction (or Diode)
1
Depletion Region
 Border between p-type and n-type is called the pn junction
 led to many semiconductor devices (diodes, BJT, etc.)
 Electrons migrate (diffuse or spread) across the junction
and fill the holes leaving behind positive ions in a region
called depletion region.
© McGraw-Hill
41
The Unbiased Diode
EF
Barrier (Built-in) Potential
𝑘𝑇 𝑁𝐴 𝑁𝐷
VF = 𝑞 𝑙𝑛 𝑛 2
𝑖
~ 0.7 V
 The electric field results in a “barrier” to electron
movement with built-in potential  Equilibrium
 To a first approximation, the electric field eventually
stops the diffusion of electrons across the junction.
© McGraw-Hill
42
Depletion Layer
 Free electron enters the p region  minority carrier. With
so many holes around it, this carrier has a short lifetime 
Recombines with a hole  The hole disappears and the
free electron becomes a valence electron  No carriers.
 Each time an electron diffuses across a junction, it creates a
pair of ions. It leaves behind a pentavalent atom that is
short one negative charge  positive ion. After the
migrating electron falls into a hole on the p side, it makes a
negative ion out of the trivalent atom that captures it.
 Each pair of positive and negative ions at the junction is
called a dipole. Each dipole has an electric field (EF)
between the positive and negative ions.
© McGraw-Hill
43
Barrier Potential and Temperature
1
• When a diode is conducting, the temperature at
its PN junction is higher than the ambient air.
• As the junction temperature rises, the barrier
potential decreases by 2 mV for each degree
Celsius rise.
Silicon diode: Barrier Potential is 0.7V at 25°C.
Germanium diode: Barrier Potential is 0.3V at 25°C
V
 2 mV C
T
© McGraw-Hill
V   2 mV C  T
44
Barrier Potential and Temperature
2
• At 25°C, the Barrier Potential is 0.7V.
• Determine the Barrier Potential if the ambient
air around the diode increased to 30°C.
Vdiode
2mV 

 Barrier Potential   T C 


C


Vdiode
2mV 

 0.7V  5C 
C 

Vdiode  0.7V  10 mV
Vdiode  0.69V
© McGraw-Hill
45
EF (Built-in)
Forward Bias
Free Electrons
EF (Battery)
Free electron  Recombination  Valence electron  Exit
A “push” is required to move an electron across the
barrier. If the applied voltage exceeds barrier potential
(0.7V in Si), the diode will conduct current.
© McGraw-Hill
46
Holes
Reverse Bias
Electrons
EF (Battery)
The +ve battery terminal attracts free electrons, and -ve
terminal attracts holes. Holes and free electrons flow
away from the junction. The depletion layer expands
until equilibrium  no current flows across the barrier.
© McGraw-Hill
47
Diode Bias Summary
© McGraw-Hill
48
Reverse Bias Leakage Current IS
Ireverse  0
After equilibrium  Thermal energy creates free electron
and hole in the depletion region  Most Recombine with
majority carriers  Occasionally very few manage to
move across the junction  This minority carrier current
is called saturation current IS  Temperature dependent
 Very small (~ Zero)  Doubles every 100C rise
© McGraw-Hill
49
Surface-Leakage Current
• Flows on the surface of the crystal
in a reverse biased diode.
• The atoms on the top and bottom
rows have no neighbor so only 6
electrons in orbit (2 holes in each
atom).
• Surface of crystal is like a p-type
semiconductor.
• Surface-leakage current is directly
proportional to the reverse voltage
• Very small, can be considered ~ 0A
© McGraw-Hill
VR
RSL 
I SL
50
Breakdown
• If reverse biased with enough voltage, a diode
will conduct.
• Typical breakdown ratings range from 50 volts
to 1000 volts.
Access the text alternative for slide images.
© McGraw-Hill
51
Breakdown Avalanche
•
When the reverse voltage increases & the
breakdown voltage is reached, it forces the
minority carriers to move more quickly. They
collide with atoms of the crystal and with
enough energy can knock valence electrons
loose, producing free ones.
•
These new minority carriers then join the
existing minority carriers to collide with other
atoms. The process is like a geometric sequence.
A large number of the minority carriers suddenly
appears in the depletion layer and the diode
conducts heavily.
© McGraw-Hill
52
Recap of the PN Junction
1
• At 25 °C, the barrier potential for a silicon PN
junction is approximately 0.7 V (the built–in
voltage is 0.3V for germanium)
• If the PN junction is forward biased at greater
than 0.7V, it will conduct current.
• If the PN junction is reversed biased, it will not
conduct current unless the diode goes into
“breakdown.”
© McGraw-Hill
53
Recap of the PN Junction
2
• The diode built-in-voltage VF is a function of
temperature
• Electron diffusion creates ion pairs called dipoles.
• Each dipole has an associated electric field.
𝑉𝐹 =
𝑘𝑇
𝑁𝐴 𝑁𝐷
ln 2 ~700𝑚𝑉
𝑞
𝑛𝑖
(@ room)
• VT = kT/q is called the thermal voltage (~ 25mV @ room)
• K is Boltzmann's constant (1.38x10-23 J/oK), T is temp. in
Kelvin, q is unit charge (1.6x10-19)
© McGraw-Hill
54
Because learning changes everything.
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© 2021 McGraw-Hill. All rights reserved. Authorized only for instructor use in the classroom.
No reproduction or further distribution permitted without the prior written consent of McGraw-Hill.
®