New Generation Publishing



Easy, Hands On Electronics Books



Second Edition



A Practical Handbook to

Digital Electronics




Copyright 2005, 2012 -2nd edition by Alireza H. Fassih




All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, xerography, recording, or by incorporating into any information storage or retrieval system, without the written permission from the author. Making copies of any part of this book for any purpose is a violation of United States copyright laws.


The author or the publisher does not warrant the accuracy of the materials in this book. Neither the author nor the publisher is liable or responsible for any damages or injuries

as a result of using the materials in this book directly or indirectly.



Visit our web site at

Printed in the United States of America



ISBN 978-0-9776054-7-7 / 0-9776054-7-7




The main purpose of this handbook is a HANDS-ON APPROACH in learning digital circuits.

In each section, a digital chip is introduced and then a software/hardware circuit will follow. The software circuit can be implemented by electronic circuit design and simulation software such as Multisim .


The main goal of this handbook is to create a vast visualization of the working function of the digital electronics circuitries. Based on my experience in teaching electronics, students had more problems with setting up the hardware circuits than software circuits. Therefore, one of my main intentions in writing this handbook is to guide the students through setting up a complete wiring of the circuits.


This handbook is a COMPREHENSIVE COVERAGE of the practical working of the digital circuits and can be used as digital electronics textbook/lab manual in digital electronics course.








Chapter 1: Number Systems



1.1         Decimal Digits and Numbers


1.2         Binary Digits and Numbers


1.3         Binary to Decimal Conversion


1.4         Decimal to Binary Conversion


1.5         Hexadecimal Digits and Numbers


1.6         Binary to Hexadecimal Conversion


1.7         Hexadecimal to Binary Conversion


1.8         Hexadecimal to Decimal Conversion


1.9         Octal Digits and Numbers


1.10    Binary to Octal Conversion


1.11    Octal to Binary Conversion


1.12    Octal to Decimal Conversion


1.13    1s Complement of a Binary Number


1.14    2s Complement of a Binary Number


1.15    Addition of two Binary Numbers


1.16    Representation of Voltages in Digital Circuits with Binary Digits




Chapter 2: Logic Gates



2.1 Inverter Gate

2.2 OR Gate


2.3 AND Gate


2.4 NOR Gate


2.5 NAND Gate


2.6 Exclusive - OR Gate


2.7 Logic Probe




Chapter 3: Combinational Logic Chips



3.1 BCD-to-Decimal Decoder

3.2 BCD-to-7 Segment Decoder


3.3 Decimal to BCD Encoder


3.4 8-Input Data Multiplexer


3.5 1-Line-to-16 Line De-multiplexer


Chapter 4: Latches and Flip-Flops



4.1 S-R Latch

4.2 Gated S-R Latch


4.3 Gated D Latch


4.4 D Flip-Flop


4.5 J-K Flip-Flop


Chapter 5: Counters



5.1 Asynchronous 2-bit Counter

5.2 Asynchronous 3-bit Counter


5.3 Asynchronous 4-bit Counter


5.4 Synchronous 2-bit Counter


5.5 Synchronous 3-bit Counter


5.6 Synchronous 4-bit Counter



Chapter 6: Shift Registers

6.1 One-bit Shift Register

6.2 Two-bit Shift Register


6.3 Four-bit Shift Register


6.4 Four-bit Parallel in / Parallel out Shift Register


6.5 Eight-bit Serial in / Parallel out Shift Register


6.6 Eight-bit Parallel in / Serial out Shift Register


6.7 Four-bit Universal Shift Register


6.8 Johnson Shift Register Counter


6.9 Ring Shift Register Counter


Chapter 7: Digital-Analog Conversion


7.1 Digital-to-Analog Conversion


7.2 Analog-to-Digital Conversion