chapter 01

In the name of Allah, the Most Gracious the Most Merciful

Prepared By : Engr KSK 1

ELECTRONICSLecture No.01


Course Outline

Part-1 (25%)

Semiconductors, rectifiers, transistors, relays, Operational

Amplifiers.

Part-2 (75%)

Number systems, Boolean Algebra, gates. Combinational logic

(adders, comparators, decoders, multiplexers, etc.) Sequential

logic (flip-flops, registers, counters, ROM, PROM, EPROM).

Microprocessors (registers, ALU, CU, memory, address, data and

control buses). ADC and DAC. Micro-controllers


Recommended Books1. Electronic Devices by Floyd, 7th Edition, Prentice hall

2. Digital Design by M. Morris Mano & Michael D. Ciletti , 4th

edition

3. Electronic Principles By Malvino, A.Paul, McGraw Hill

4. Digital Computer Electronics 2nd Edition , By Malvino , McGraw

Hill


Grading Policy Sessionals (30%)

Class assignments Chapter end problems

Quizzes Project

Mid-Semester Exam (20%) End-Semester Exam (50%) Lab Sessionals (15%) Lab Viva (10%)

(75 %)

(25 %)


Prepared By : Engr KSK

SEMICONDUCTOR BASICS

Friday, April 7, 2023

CHAPTER NO. 01

6


Objectives

Discuss the basic structure of atoms

Discuss semiconductors, conductors, and insulators

Discuss covalent bonding in silicon

Describe how current is produced in a semiconductor

Describe the properties of n-type and p-type semiconductors

Describe a diode and how a pn junction is formed

Discuss the bias of a diode

Analyze the voltage-current (V-I) characteristic curve of a diode

Discuss the operation of diodes and explain the three diode models

7


Atomic Structure

An atom is the smallest particle of an element that retains the

characteristics of that element , which gives each element a unique

atomic structure

All matter is made of atoms and all atoms consist of electrons, protons,

and neutrons

The Bohr model of an atom showing electrons in orbits around the

nucleus, which consists of protons and neutrons. The "tails" on the

electrons indicate motion can be pictorially shown in the next slide

8


Bohr model of an atom

9


Two Simplest Atoms (Hydrogen &

Helium)

10


Energy level increases as the distance from the

nucleus increases

11


Diagram of carbon atom

12


Energy bands of three types of

materials

13


Diagram of silicon and copper atoms

14


Diagram of silicon and germanium

atoms

15


Illustration of covalent bond in silicon

atom

16


Energy band diagram of a pure silicon

atom

17


Creation of Electron-Hole pair in a

silicon crystal

18


Illustration of Electron Hole pair (Generation &

Recombination)

19


Electron current in intrinsic silicon

20


Hole current in intrinsic silicon

21


Pentavalent impurity atom in a silicon

crystal structure

22


Trivalent impurity atom in a silicon

crystal structure

23


Basic diode structure

24


Formation of the Depletion region

25


Energy diagrams illustrating the formation of PN

junction and depletion region

26


Diode connected with forward bias

27


Voltage due to the barrier potential across the

depletion region

28


Depletion region narrows and voltage

drops when diode is forward bias

29


Diode connected with reverse bias

30


Diode after reverse voltage is applied

31


Small reverse current in a reverse

bias diode

32


VI characteristic curve for a diode

33


Diode structure and schematic

symbol

34


Forward & Reverse bias connection

of a diode

35


DIODE MODELS

36


Ideal model of a diode

37


Practical model of a diode

38


Complete model of a diode

39


Example:

40


Solution:

41


Solution: (contd…)

42

chapter 01

Documents

silicon crystal

depletion

forward bias

intrinsic

bohr model

pn junction

engr ksk

semester exam