1. DIGITAL ELECTRONICS BEL 20303

2. DR. FARIZA MOHAMAD C

3. LEARNING OUTCOMES:
At the end of this course the student will be able to:
Analyse the operation of functional combinatorial and sequential logic circuits.
Construct a simple digital system using simulation tools.
Discuss importance of digital circuits in current technology trend.

4. CONTENT 1 1.0 Introduction To Digital System Numerical representation
WEEK
CONTENTS
ASSESSMENT 1
1.0 Introduction To Digital System
Numerical representation
Digital and analog system
Advantages of using digital over analog
Limitation of digital system
Overcoming the limitation of an analog world
TTL and CMOS technology
Test 1
Assignment 2
2.0 Numerical Representation
Binary system
Binary arithmetic
Signed and unsigned numbers.
Signed numbers arithmetic operation
Hexadecimal numbering system
Octal numbering system
Digital codes, BCD, Gray, ASCII, error detection
BCD addition
Final Exam

5. WEEK CONTENTS ASSESSMENT 3-5
3.0 Basic Gates and Combinational Logic Circuit
Introduction to basic gates
Analyzing combinational logic circuits.
Designing a logic circuit from Boolean expression
Designing a logic circuit from truth table
Boolean theorem and Karnaugh-map approach
Universality of the NAND and NOR gates
Test 1
Final Exam
6-8
4.0 Function of Combinational Logic Circuit
Half adder and full adder circuits
4-bit parallel binary ripple carry adder circuit
4-bit parallel binary carry look ahead adder circuit
BCD adder circuit
Decoder and Encoder
Multiplexer and Demultiplexer
Comparator
Code converters
Parity generator and checker
Test 2

6. CONTENT 9 5.0 Flip-Flops NAND and NOR latch D latch
WEEK
CONTENTS
ASSESSMENT 9
5.0 Flip-Flops
NAND and NOR latch
D latch
Active high and active low concept
Edge triggered SC flip-flop
Edge triggered JK flip-flop
Edge triggered D flip-flop
Flip-flop applications
Test 2
Final Exam
10-11
6.0 Counters and Registers
Asynchronous counter
Synchronous counter
Counter applications
Design using the Finite State Machine method
Serial in/serial out shift register
Serial in/parallel out shift register
Parallel in/parallel out shift register
Parallel in/serial out shift register

7. CONTENT FINAL EXAMINATION 12
WEEK
CONTENTS
ASSESSMENT 12
7.0 Interfacing Digital System with Analog
Digital-to-analog conversion
DAC circuitry
Integrated DAC circuit
Analog-to-digital conversion
Digital-ramp ADC.
Successive approximation ADC
Flash ADC
Assignment
FINAL EXAMINATION

8. ASSESSMENT 1. Assignment/Projects : 15 % 2. Quiz 5 % 3. Test 1 4.
15 % 2.
Quiz
5 % 3.
Test 1 4.
Test 2 5.
Final Examination
50 %
Total
100 %

9. LECTURE ATTENDANCE / REGULATION
Students must attend lectures not less than 80% of the contact hours for every subject including Compulsory Attendance Subjects (Hadir Wajib – HW) and Attendance Only Subjects (Hadir Sahaja – HS)
Students who do not fulfill item (1) will not be allowed to attend further lectures and sit for any further examination. Zero mark (0) will be given to students who fail to comply with item (1). While for Compulsory Attendance Subjects (Hadir Wajib – HW), those who fail to comply with item (1) will be given Failure Attendance (Hadir Gagal – HG).
Students must obey all rules and regulations of the university and must discipline themselves in order to avoid any disciplinary actions against them.
Student must obey safety regulations during learning and teaching process.

10. CHAPTER 1 INTRODUCTION TO DIGIT
Numerical representation
Digital and analog system
Advantages of using digital over analog
Limitation of digital system
Overcoming the limitation of an analog world
TTL and CMOS technology

11. Learning Outcomes At the end of this chapter, you must be able to:
Distinguish between analog & digital representations
State the advantages and disadvantages of digital techniques compared with analog

12. 1.1 Numerical Representations
Most naturally occurring physical quantities in our world are analog in nature.
Quantities are measured, monitored, recorded, manipulated arithmetically, observed in most physical systems.
Important when dealing with quantities
To represent their values efficiently and accurately
2 ways to represent them:
1) ANALOG representation
2) DIGITAL representation

13. Analog Representation
Represent a quantity by a continuously variable, proportional indicator
Characteristic of analog quantities
They can vary over a continuous range of values
Example
1) Speedometer
2) Thermometer
Use a mechanical means

14. Digital Representation
Represent a quantity by a symbol, called digits.
Characteristic of digital quantities
They are varied in discrete steps
Example
1) Digital Clock
2) Digital weighting scale

15. Digital Number Systems
There are many numbering systems used in digital technology.
Decimal  most familiar to us
Binary
Octal
Hexadecimal

16. Representing Binary Quantities
The information being processed in digital systems is presented in binary form.
Binary quantities can be represented by any device that has only two operating states or possible conditions
Example:
A switch has only 2 states  open or closed
Information stored in CD  holes are burnt form pits (non-reflective) as ‘1’ or reflective areas as ‘0’
Diode  conducting or non-conducting

17. Logic Level
The voltages used to represent at 1 and a 0 are called logic levels.
HIGH
goto slide8
please refer to slide 'disadvantage of the digital techniques'.
must take into account the suitable range to avoid misjudgement of the input/output data.
LOW
Example: Using voltage level to represent the binary values

18. 1.2 Digital & Analog Systems
DIGITAL SYSTEM
Combination of devices designed to manipulate logical information or physical quantities that are represented in digital form.
Example: digital calculator
ANALOG SYSTEM
Devices that manipulate physical quantities that are represented in analog form.
Example: magnetic tape recording and playback equipment

19. Computer
All the stored and processed data are in binary form.

20. CD
CD player: digital and analog parts co-exist together (source: How Stuff Works website)

21. 1.3 Advantages of Digital Techniques
Digital systems are easier to design
Information storage is easy
Accuracy & precision are easier to maintain throughout the system
Operation can be programmed
Digital circuits are less affected by noise
Digital circuitry can be fabricated on IC chips

22. 1.4 Disadvantages of Digital Techniques
The real world is analogue
Processing digitised signals takes time
Digital circuits use more energy than analogue circuits & produce more heat
Digital circuits are made from analogue components – must make sure the digital behaviour is not affected by the analogue
Digital circuits are sometimes more expensive (in small quantity)

23. 1.5 Digital Systems Overcome the Drawback of Analog Systems
When dealing with analogue inputs and outputs, four steps must be followed
Convert the physical variable to an electrical signal (analogue)
Convert the electrical (analogue) signal into digital form  ADC (Analogue Digital Converter)
Process (operate on) the digital information
Convert the digital outputs back to real-world analogue form  DAC (Digital Analogue Converter)

24. Example: Block diagram for a digital temperature control system

25. 1.6 TTL & CMOS technology

26. Reference
Thomas L. Floyd, Digital Fundamentals (10th edition), Pearson, 2009
Ronald J. Tocci, Neal S. Widmer & Gregory L. Moss, Digital Systems: Principles and Applications (11th edition), Pearson, 2011