# Digital Electronics-1

AIMS

To develop knowledge & skill on number systems, binary arithmetic operation and codes.

To provide knowledge & skill on logic gates, ICs, logic circuits and Boolean algebra.

To assist to acquire the knowledge & skill on combinational logic circuit.

SHORT DESCRIPTION

Basic concept of digital electronics; Number system & codes; Logic gates & ICs; Boolean algebra and logic simplification & Combinational logic circuits.

DETAIL DESCRIPTION

BASIC CONCEPT OF DIGITAL ELECTRONICS

1 Understand the aspects of digital electronics.

1.1 Define digital electronics.

1.2 Mention the characteristics of digital and analog signal.

1.3 State the advantages of working in digital mode.

1.4 Define logic level.

1.5 Mention how voltage levels are used to represent digital quantities.

1.6 ¬Describe various parameters of a pulse waveform such as rise time, fall time, pulse width, frequency, period, and duty cycle.

NUMBER SYSTEMS & CODES.

2 Understand the number system and binary arithmetic operation.

2.1 Describe decimal, binary, octal and hexadecimal number system.

2.2 Convert one number system to another.

2.3 Compute binary arithmetic (addition, subtraction, multiplication and division) including binary point.

2.4 Compute 1`s and 2`s complement subtraction.

2.5 State the applications of different number system.

2.6 Explain the representation of unsigned and floating point number in binary.

3 Understand the arithmetic codes and code conversion.

3.1 Define codes.

3.2 Distinguish weighted & non-weighted codes.

3.3 Describe the 8421, Excess–3 and other popular BCD codes?

3.4 Describe the addition and subtraction of 8421, Excess-3 and BCD coded number.

3.5 State the meaning of gray code.

3.6 Convert gray code to binary and vice versa.

3.7 State parity checked code and Hamming code.

3.8 Describe the error detection and correction with Hamming code. and parity checked code.

3.9 Describe the ASCII code & Unicode.

LOGIC GATES & ICs

4 Understand the concept of Logic gates.

4.1 Define logic gate..

4.2 Define AND, OR, NOT, NOR, NAND, and EX-OR gates.

4.3 Draw the symbols and use of logic gates.

4.4 Prepare the truth table and Boolean equations of logic gates.

4.5 Give the physical concept of AND, OR and NOT operations.

4.6 Explain the AND, OR and NOT operation with electronic circuit.

5 Understand the features of the logic families and digital IC’s.

5.1 Mention the classification logic families.

5.2 Define SSI, MSI, LST and VLSI.

5.3 List the types of unipolar and bipolar logic families.

5.4 State the characteristics of digital IC’s.

5.5 State the meaning of the terms propagation delay time, speed, noise immunity, logic level, power dissipation, fan-in, fan-out, floating input, Sourcing and sinking, standard loading, loading rules, operating temperature and power rating of logic circuits.

5.6 State the difference of DTL, TTL, MOS, I2L and ECL families.

6 Understand the concepts of electronic circuit of logic gates.

6.1 Describe the operation of open collector & totempole output circuit for standard TTL NAND gate.

6.2 Describe the CMOS circuit operation.

6.3 State special logic gates such as buffer, tri-state and expandable gates.

6.4 Mention the basic principle of ORing and ANDing.

6.5 Define fixed function Integrated circuit (IC).

6.6 classify fixed function IC

6.7 Mention IC package, code numbers, important specification of TTL/MOS commercial IC gates.

6.8 Distinguish the difference between 74 and 54 series of logic circuit.

BOOLEAN ALGEBRA & LOGIC SIMPLIFICATION

7 Understand the process of logic simplification.

7.1 State the single and multi-variable theorems of Boolean algebra.

7.2 Explain the universality of NAND and NOR gates .

7.3 State DeMorgan’s theorems and utilize them to simplify the logic expression.

7.4 State the terms-Sum of Product (SOP) form and Product Of Sum (POS) form.

7.5 Determine the SOP & POS form from truth table.

7.6 State the steps of algebraic simplification.

7.7 Define Karnaugh Map.

7.8 State the structure of Karnaugh map.

7.9 State the simplification process of Boolean expression from a K-map and design logic circuit ( up to 4 variables).

COMBINATION LOGIC CIRCUIT.

8 Understand the features of combinational logic circuits.

8.1 Define combinational logic circuit with example.

8.2 Mention the application of combinational logic circuit.

8.3 Describe the operation of half and full adder with logic circuit and expression.

8.4 Describe the operation of controlled inverter.

8.5 State the principle of half subtraction and full subtraction.

8.6 Describe the operation of 4 bit parallel adder.

8.7 Describe the operation of 4 bit subtraction circuit..

8.8 Describe the operation of parity generator and detector circuit.

8.9 Describe the operation of 4 bit BCD & Excess-3 adder.

8.10 Describe the operation of multipliers & divisors.

9. Understand the concepts of encoder, decoder and display devices.

9.1 Describe the operation of encoder, priority encoder and decoder circuit.

9.2 State the principle of operation of LCD, seven-segment display and dot matrix display.

9.3 Describe the operation and application of commonly available encoder & decoder.

9.4 Describe the operation of commonly used 4-bit BCD decoder/driver for seven segment display of common anode/cathode type.

10 Understand the features of multiplexers and demultiplexers.

10.1 Define multiplexers and demultiplexers.

10.2 Describe the operation of 2 and 4 input multiplexer and demultiplexer with logic diagram.

10.3 State the use of multiplexer & demultiplexer.

10.4 State the Pin signals of 2/4 input Multiplexer.

10.5 State the Pin signals of a 1 to 4 line Demultiplexer

10.6 Explain the operation of comparator.

10.7 Describe the Pin diagram of commonly used 4-bit comparator ICs.

10.6 Distinguish between Decoder and Demultiplexer.

SEQUINTIAL LOGIC CIRCUITS

11 Understand the features of sequential logic circuits.

11.1 Define (i) sequential logic circuit (ii) Clock (iii) Timing diagram. (iv) Latch (v) Flip-Flop

11.2 Explain the operation of logic circuit of a basic SR latch.

11.3 Describe the operation of logic circuit of gated SR and D latch with waveform and truth table.

11.4 Mention the difference between latch and flip-flop.

11.5 Give concept of positive & negative edge triggering and level triggering,

11.6 Explain the operation of logic circuit of J-K, D, T and Master-Slave J-K flip-flop with timing diagram and truth table..

11.7 State the function of asynchronous inputs .

11.8 Describe the pin diagram and internal architecture of commonly used flip-flop ICs Such as 74279,7474, 7475, 7476,74112.

11.9 Describe the basic elements in a 555 timer .

11.10 Set up a 555 timer as clock generator.

Practical :

1 To Verify the truth tables of logic gates (OR, AND, NOT)

1.1 Select logic gate ICs.

1.2 Draw the pin diagram and internal connection.

1.3 Select appropriate circuits, required tools, equipments and materials.

1.4 Connect the circuits as per diagram.

1.5 Switch on the DC power supply,

1.6 Verify the truth tables.

2 To Verify the truth tables of logic gates (NAND, NOR gate).

2.1 Select logic gate ICs.

2.2 Draw the pin diagram and internal connection.

2.3 Select appropriate circuits, required tools, equipments and materials.

2.4 Connect the circuits as per diagram.

2.5 Switch on the DC power supply,

2.6 Verify the truth tables.

3 Show the operation of the electronic circuits of basic gates.

3.1 Draw appropriate circuits of basic bates using active and passive components.

3.2 Select required tools, equipments and materials.

3.3 Connect the circuits as per diagram.

3.4 Switch on the DC power supply,

3.5 Verify the truth tables.

4 Verify the Truth table of X-OR & X-NOR gate using basic gates.

4.1 Select logic gate ICs.

4.2 Draw the pin diagram and internal connection.

4.3 Select appropriate circuits, required tools, equipments and materials.

4.4 Connect the circuits as per diagram.

4.5 Switch on the DC power supply,

4.6 Verify the truth tables.

5 To design & develop a code converter circuits and observe its output operation.

5.1 Select logic gate ICs.

5.2 Draw the pin diagram and internal connection.

5.3 Select appropriate circuits, required tools, equipments and materials.

5.4 Connect the circuits as per diagram.

5.5 Switch on the DC power supply,

5.6 Verify the code conversion tables.

6 To Show the operation of NAND gate as universal gates.

6.1 Select logic gate IC of NAND gate.

6.2 Draw the pin diagram and internal connection.

6.3 Select appropriate circuits, required tools, equipments and materials.

6.4 Connect the circuits as per diagram for AND OR & NOT gate.

6.5 Switch on the DC power supply,

6.6 Verify the truth tables of AND OR & NOT gate.

7 To Show the operation of NOR gate as universal gates.

7.1 Select logic gate IC of NOR gate.

7.2 Draw the pin diagram and internal connection.

7.3 Select appropriate circuits, required tools, equipments and materials.

7.4 Connect the circuits as per diagram for AND OR & NOT gate.

7.5 Switch on the DC power supply,

7.6 Verify the truth tables of AND OR & NOT gate.

8 To develop the circuit to proof the Demorgan’s theorems.

8.1 Select logic gate ICs.

8.2 Draw the pin diagram and internal connection.

8.3 Select appropriate circuits, required tools, equipments and materials.

8.4 Connect the circuits as per diagram.

8.5 Switch on the DC power supply,

8.6 Verify the theorem.

9 Verify the functions of half adder .

9.1 Select ICs.

9.2 Draw the pin diagram and internal connection.

9.3 Draw appropriate circuits.

9.4 Select required tools, equipments and materials.

9.5 Connect the circuits as per diagram.

9.6 Switch on the DC power supply,

9.7 Verify the truth tables.

10 Verify the functions of full adder.

10.1 Select ICs.

10.2 Draw the pin diagram and internal connection.

10.3 Draw appropriate circuits.

10.4 Select required tools, equipments and materials.

10.5 Connect the circuits as per diagram.

10.6 Switch on the DC power supply,

10.7 Verify the truth tables.

11 Verify the output operation of binary 4 bit parallel adder.

11.1 Select appropriate ICs.

11.2 Draw the pin diagram and internal connection.

11.3 Draw appropriate circuits.

11.4 Select required tools, equipments and materials.

11.5 Connect the circuits as per diagram.

11.6 Switch on the DC power supply,

11.7 Verify the truth tables.

12 Verify the functions of Subtractor .

12.1 Select appropriate ICs.

12.2 Draw the pin diagram and internal connection.

12.3 Draw appropriate circuits.

12.4 Select required tools, equipments and materials.

12.5 Connect the circuits as per diagram.

12.6 Switch on the DC power supply,

12.7 Verify the truth tables.

13 Verify the output of a 4-bit 2`s compliment subtractor.

13.1 Select appropriate ICs.

13.2 Draw the pin diagram and internal connection.

13.3 Draw appropriate circuits.

13.4 Select required tools, equipments and materials.

13.5 Connect the circuits as per diagram.

13.6 Switch on the DC power supply,

13.7 Verify the truth tables.

14 To Show the operation of encoder .

14.1 Select appropriate ICs.

14.2 Draw the pin diagram and internal connection.

14.3 Draw appropriate circuits.

14.4 Select required tools, equipments and materials.

14.5 Connect the circuits as per diagram.

14.6 Switch on the DC power supply,

14.7 Verify the truth tables.

15 To Show the operation of decoder.

15.1 Select appropriate ICs.

15.2 Draw the pin diagram and internal connection.

15.3 Draw appropriate circuits.

15.4 Select required tools, equipments and materials.

15.5 Connect the circuits as per diagram.

15.6 Switch on the DC power supply,

15.7 Verify the truth tables.

16 To Show the operation of a decoder driver & display operation using 7 segment display.

16.1 Select appropriate ICs.

16.2 Draw the pin diagram and internal connection.

16.3 Draw appropriate circuits.

16.4 Select required tools, equipments and materials.

16.5 Connect the circuits as per diagram.

16.6 Switch on the DC power supply,

16.7 Verify the truth tables.

17 Show the operation of multiplexer.

17.1 Select appropriate ICs.

17.2 Draw the pin diagram and internal connection.

17.3 Draw appropriate circuits.

17.4 Select required tools, equipments and materials.

17.5 Connect the circuits as per diagram.

17.6 Switch on the DC power supply,

17.7 Verify the truth tables.

18 Show the operation of demultiplexer.

18.1 Select appropriate ICs.

18.2 Draw the pin diagram and internal connection.

18.3 Draw appropriate circuits.

18.4 Select required tools, equipments and materials.

18.5 Connect the circuits as per diagram.

18.6 Switch on the DC power supply,

18.7 Verify the truth tables.

19 Show the operation of parity generator and detector.

19.1 Select appropriate ICs.

19.2 Draw the pin diagram and internal connection.

19.3 Draw appropriate circuits.

19.4 Select required tools, equipments and materials.

19.5 Connect the circuits as per diagram.

19.6 Switch on the DC power supply,

19.7 Verify the truth tables.

20 Verify the truth table of different S-R flip-flops.

20.1 Select appropriate ICs.

20.2 Draw the pin diagram and internal connection.

20.3 Draw appropriate circuits.

20.4 Select required tools, equipments and materials.

20.5 Connect the circuits as per diagram.

20.6 Switch on the DC power supply,

20.7 Verify the truth tables.

21 Verify the truth table of different J-K flip-flops.

21.1 Select appropriate ICs.

21.2 Draw the pin diagram and internal connection.

21.3 Draw appropriate circuits.

21.4 Select required tools, equipments and materials.

21.5 Connect the circuits as per diagram.

21.6 Switch on the DC power supply,

21.7 Verify the truth tables.

22 Verify the truth table of different D flip-flops.

22.1 Select appropriate ICs.

22.2 Draw the pin diagram and internal connection.

22.3 Draw appropriate circuits.

22.4 Select required tools, equipments and materials.

22.5 Connect the circuits as per diagram.

22.6 Switch on the DC power supply,

22.7 Verify the truth tables.

23 Verify the truth table of different T flip-flops.

23.1 Select appropriate ICs.

23.2 Draw the pin diagram and internal connection.

23.3 Draw appropriate circuits.

23.4 Select required tools, equipments and materials.

23.5 Connect the circuits as per diagram.

23.6 Switch on the DC power supply,

23.7 Verify the truth tables.

24 Construct a Clock generator circuit using 555 timer IC. and observe the output.

24.1 Draw the pin diagram and internal connection.

24.2 Draw appropriate circuits.

24.3 Select required tools, equipments and materials.

24.4 Connect the circuits as per diagram.

24.5 Switch on the DC power supply,

24.6 Observe the on LED or CRO..

REFERENCE BOOKS

1. Digital Fundamentals

– Thomas L. Floyd

2. Digital Computer Electronics (An introduction to microcomputers)

Albert Paul Malvino

3. Digital Principles

Roger L. Tokhem

5. Digital system

Ronald J. Tocci and Widmer.

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