As per the Latest Syllabus of JNTU Hyderabad Electronic Devices and Circuits About the Authors S Salivahanan is the Principal of SSN College of Engineering, Chennai. He obtained his BE degree in Electronics and Communication Engineering from PSG College of Technology, Coimbatore, ME degree in Communication Systems from NIT, Trichy, and PhD in the area of Microwave Integrated Circuits from Madurai Kamaraj University. He has more than three and a half decades of teaching, research and industrial experience, both in India and abroad. He had also taught at NIT, Trichy; AC College of Engineering and Technology, Karaikudi; RV College of Engineering, Bangalore; Dayananda Sagar College of Engineering, Bangalore; Mepco Schlenk Engineering College, Sivakasi; and Bannari Amman Institute of Technology, Sathyamangalam. He served as a mentor for the MS degree under the distance learning programme offered by Birla Institute of Technology and Science, Pilani. He has industrial experience as Scientist/Engineer at Space Applications Centre, ISRO, Ahmedabad; Telecommunication Engineer at State Organisation of Electricity, Iraq, and Electronics Engineer at Electric Dar Establishment, Kingdom of Saudi Arabia. His areas of interest are Microwave Integrated Circuits, Low and High Frequency EM Fields, Digital Signal Processing and Biomedical Instrumentation. He is also the author of popular books titled Basic Electrical and Electronics Engineering, Linear Integrated Circuits and Electronic Devices and Circuits published by McGraw Hill Education (India), and Digital Signal Processing by McGraw Hill Education (India) and McGraw Hill International which has also been translated in Mandarin, the world’s largest spoken variation of the Chinese language. He has also authored the book Digital Circuits and Design and also published several papers at national and international levels. Professor Salivahanan is the recipient of IEEE Outstanding Branch Counsellor and Advisor Award in the Asia-Pacific region for 1996–97. He is a Senior Member of IEEE, Fellow of IETE, Fellow of Institution of Engineers (India), Life Member of ISTE and Life Member of Society for EMC Engineers. N Suresh Kumar is the Principal of Velammal College of Engineering and Technology, Madurai. He received his BE in Electronics and Communication Engineering from Thiagarajar College of Engineering, Madurai, with an ME in Microwave and Optical Engineering from AC College of Engineering and Technology, Karaikudi, and PhD in the field of RF interconnects from Madurai Kamaraj University. He has almost three decades of teaching and research experience and his areas of interest include Microwave Communication, Optical Communication and Electromagnetic Compat- ibility. He is a co-author of the book Electronic Devices and Circuits published by McGraw Hill Education (India). He has published several papers at national and inter- national levels and is also a Life Member of both IETE and ISTE. As per the Latest Syllabus of JNTU Hyderabad Electronic Devices and Circuits S Salivahanan Principal SSN College of Engineering Chennai N Suresh Kumar Principal Velammal College of Engineering and Technology Madurai McGraw Hill Education (India) Private Limited NEW DELHI McGraw Hill Education Offices New Delhi NewYork St Louis SanFrancisco Auckland Bogotá Caracas Kuala Lumpur Lisbon London Madrid MexicoCity Milan Montreal San Juan Santiago Singapore Sydney Tokyo Toronto McGraw Hill Education (India) Private Limited Published by McGraw Hill Education (India) Private Limited P-24, Green Park Extension, New Delhi 110 016 Electronic Devices and Circuits Copyright © 2015 by the McGraw Hill Education (India) Private Limited No part of this publication may be reproduced or distributed in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise or stored in a database or retrieval system without the prior written permission of the author. 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Ed: Tina Jajoriya Senior Graphic Designer—Cover: Meenu Raghav General Manager—Production: Rajender P Ghansela Manager—Production:Reji Kumar Information contained in this work has been obtained by McGraw-Hill Educa- tion (India), from sources believed to be reliable. However, neither McGraw-Hill Education (India) nor its authors guarantee the accuracy or completeness of any information published herein, and neither McGraw-Hill Education (India) nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that McGraw-Hill Education (India) and its authors are supplying information but are not attempting to render engineering or other professional services. If such ser- vices are required, the assistance of an appropriate professional should be sought. Typeset at The Composers, 260, C.A. Apt., Paschim Vihar, New Delhi 110 063 and printed at Cover Printer: Contents Preface xi 1. PN Junction Diode & Special-Purpose Electronic Devices 1.1–1.67 1.1 Introduction 1.1 1.2 Classification of Semiconductors 1.1 1.2.1 Intrinsic Semiconductor 1.1 1.2.2 Extrinsic Semiconductor 1.2 1.3 Qualitative Theory of PN junction diode 1.4 1.3.1 PN Junction Diode in Equilibrium with no Applied Voltage 1.4 1.3.2 Operation and Volt-Ampere Characteristics of a Diode under Forward Bias Condition 1.9 1.3.3 Operation and Volt-Ampere Characteristics of a diode under Reverse Bias Condition 1.10 1.3.4 Limiting Values of PN Junction Diode 1.11 1.4 PN Junction as a Diode 1.11 1.5 Energy Band Structure of Open Circuited PNJunction 1.12 1.6 Diode Equation 1.15 1.7 Ideal versus Practical—Resistance levels (Static and Dynamic) 1.21 1.8 Transition or Space Charge (or Depletion Region) Capacitance (C ) 1.26 T 1.8.1 Step-graded Junction 1.27 1.9 Diffusion (or Storage) Capacitance (C ) 1.29 D 1.10 Temperature Dependence of V–I Characteristics of Diodes 1.31 1.10.1 Effect of Temperature on Reverse Saturation Current 1.33 1.10.2 Temperature Dependance of V–I Characteristics 1.34 1.11 Diode Equivalent Circuits 1.36 1.11.1 Load Line Analysis 1.37 1.12 Piecewise Linear Diode Model/Diode Equivalent Circuits 1.39 1.13 Breakdown Mechanisms in SemiConductor Diodes 1.40 1.14 PN Diode Applications 1.42 1.15 Zener Diode Characteristics 1.42 1.15.1 Avalanche Breakdown 1.43 1.15.2 Zener Breakdown 1.43 1.15.3 Effect of Temperature on Zener Diode 1.43 1.15.4 Applications 1.44 1.16 Principle of Operation and Characteristics of Tunnel Diode 1.45 1.17 P rinciple of Operation and Characteristics of Varactor Diode 1.48 1.18 Priniciple of Operation of Silicon Controlled Rectifier (SCR) 1.49 1.18.1 PNPN Diode (Shockley Diode) 1.49 vi Contents 1.18.2 SCR (Silicon Controlled Rectifier) 1.50 1.18.3 Thyristor Ratings 1.52 1.18.4 Rectifier Circuits Using SCR 1.52 1.18.5 LASCR (Light Activated SCR) 1.57 1.19 Principle of operation of Semiconductor Photodiode 1.57 1.20 Specifications of Semiconductor Diodes and Special Purpose Electronic Devices 1.58 Review Questions 1.58 Objective Type Questions 1.61 Answers 1.67 2. Rectifiers and Filters 2.1–2.57 2.1 Introduction 2.1 2.2 Linear Mode Power Supply 2.2 2.2.1 Requirements of Linear Mode Power Supply 2.2 2.3 P-N Junction Diode as a Rectifier 2.3 2.4 Rectifiers 2.3 2.4.1 Half-wave Rectifier 2.3 2.4.2 Full-wave Rectifier 2.12 2.4.3 Bridge Rectifier 2.19 2.5 Harmonic Components in a Rectifier Circuit 2.23 2.6 Filters 2.24 2.6.1 Inductor Filter 2.24 2.6.2 Capacitor Filter 2.26 2.6.3 L-Section or LC Filter 2.29 2.6.4 CLC or ␲-section Filter 2.33 2.6.5 R-C Filters 2.34 2.6.6 Comparison of Filters 2.35 2.7 Voltage Regulation Using Zener Diode 2.35 2.7.1 Zener Diode Shunt Regulator 2.36 2.7.2 Emitter-follower Type Regulator 2.43 2.7.3 Principle of Obtaining a Regulated Power Supply 2.44 2.7.4 Principle of Obtaining a Dual Tracking Voltage Regulator 2.46 2.7.5 Transistorised shunt Regulator 2.47 2.7.6 Transistorised Series Regulator 2.47 2.7.7 Adjustable Voltage Regulators 2.50 Review Questions 2.52 Objective Type Questions 2.54 Answers 2.57 3. Bipolar Junction Transistor and UJT 3.1–3.49 3.1 Introduction 3.1 3.2 Construction of BJT and BJT Symbols 3.1 3.3 Transistor Biasing 3.2 3.4 BJT Operation and Transistor Current Components 3.2 3.4.1 Operation and Current Components of NPN Transistor 3.2 3.4.2 Operation and Current Components of PNP Transistor 3.3 Contents vii 3.5 Types of transistor amplifier Configuration 3.6 3.5.1 Common Base Configuration 3.6 3.5.2 Common Emitter Configuration 3.9 3.5.3 Common Collector Configuration 3.12 3.5.4 Comparison 3.13 3.5.5 Current Amplification Factor 3.13 3.6 Transistor as an Amplifier 3.14 3.7 Large signal, DC, and Small Signal CE values of Current Gain 3.15 3.8 Limits of Operation (Breakdown in Transistors) 3.16 3.8.1 Avalanche Breakdown and Multiplication 3.16 3.8.2 Reach-Through or Punch-Through 3.17 3.9 Two-Port Devices and Network Parameters 3.29 3.9.1 Z-Parameters or Impedance Parameters 3.29 3.9.2 Y-Parameters or Admittance Parameters 3.30 3.9.3 Hybrid Parameters or h-Parameters 3.30 3.9.4 Notations used in Transistor Circuits 3.31 3.10 The Hybrid Model for Two-Port Network 3.31 3.10.1 Determination of h-parameters from Transistor Characteristics 3.32 3.11 Comparison of CB, CE and CC Transistor Amplifier Configurations 3.35 3.12 UJT (Unijunction Transistor) 3.37 3.13 Specifications of BJT and UJT 3.41 Review Questions 3.42 Objective Type Questions 3.44 Answers 3.49 4. Transistor Biasing and Stabilization 4.1–4.69 4.1 Introduction 4.1 4.2 Bias Stability 4.1 4.2.1 Operating Point, Need for Biasing and Bias Stabilization against variations in V and b 4.1 BE 4.2.2 DC Load Line 4.2 4.2.3 AC Load Line 4.3 4.2.4 Stability Factor (S) 4.7 4.3 Methods of Transistor Biasing 4.8 4.3.1 Fixed Bias or Base Resistor Method 4.8 4.3.2 Emitter-Feedback Bias 4.12 4.3.3 Collector-to-Base Bias or Collector-Feedback Bias 4.14 4.3.4 Collector-Emitter Feedback Bias 4.18 4.3.5 Voltage Divider Bias, Self Bias, or Emitter Bias 4.19 4.4 Stabilization Factors 4.20 4.4.1 Common Base Stability 4.37 4.4.2 Advantage of Self Bias (Voltage Divider Bias) over other Types of Biasing 4.38 4.5 Bias Compensation using Diode and Transistor 4.38 4.5.1 Diode Compensation 4.38 4.5.2 Thermistor Compensation 4.38 viii Contents 4.5.3 Sensistor Compensation 4.39 4.6 Thermal Runaway 4.39 4.7 Thermal Resistance 4.40 4.8 Condition for Thermal Stability 4.41 4.9 Types of Heat Sinks 4.43 4.10 Analysis of A Transistor Amplifier Circuit Usingh-Parameters 4.44 4.10.1 Current Gain or Current Amplification, A 4.45 i 4.10.2 Input Impedance, Z 4.45 i 4.10.3 Voltage Gain or Voltage Amplification Factor, A 4.46 V 4.10.4 Output Admittance, Y 4.47 O 4.10.5 Voltage Amplification (A ) taking into account Vs the Resistance (R) of the Source 4.47 s 4.10.6 Current Amplification (A ) taking into account Is the Source Resistance (R) 4.48 s 4.10.7 Operating Power Gain, A 4.49 p 4.11 Simplified CE Hybrid Model 4.50 4.11.1 Generalised Approximate Model 4.51 4.11.2 Common Emitter Amplifier with Emitter Resistor 4.56 4.12 Analysis of CC Amplifier using the Approximate Model 4.58 4.13 Analysis of CB Amplifier using the Approximate Model 4.61 Review Questions 4.64 Objective Type Questions 4.66 Answers 4.69 5. Field Effect Transistors and FET Amplifiers 5.1–5.63 5.1 Introduction 5.1 5.2 Construction of N-channel JFet 5.1 5.3 Principle of Operation, Pinch-off Voltage, Volt–Ampere Characteristics and Symbols of JFET 5.2 5.4 Characteristic Parameters of the JFET 5.4 5.5 Expression for Saturation Drain Current 5.9 5.6 Slope of the Transfer Characteristic at I 5.10 DSS 5.7 The JFET Small-Signal Model 5.12 5.8 Applications of JFET 5.14 5.9 Metal Oxide Semiconductor Field Effect Transistor (MOSFET) 5.14 5.10 Construction, Principle of Operation and Symbols of Enhancement MOSFET 5.15 5.11 Construction, Principle of Operation and Symbols of Depletion MOSFET 5.16 5.12 Comparison Of MOSFET With JFET 5.17 5.13 Handling Precautions for MOSFET 5.18 5.14 Comparison of N-with P-Channel MOSFETS 5.19 5.15 Comparison of N-with P-Channel FETS 5.20 5.16 Advantages of BJT over MOSFET 5.20 5.17 Introduction 5.21 5.18 Common Source (CS) Amplifier 5.21 Contents ix 5.19 Common Drain (CD) Amplifier 5.25 5.20 Common Gate (CG) Amplifier 5.27 5.21 A Generalized FET Amplifier 5.30 5.21.1 Output from the Drain 5.30 5.21.2 For CS Amplifier 5.31 5.21.3 For CG Amplifier 5.31 5.21.4 Output from the Source 5.32 5.21.5 For CD Amplifier 5.32 5.22 Biasing The FET 5.32 5.22.1 Fixing the Q-point 5.32 5.22.2 Self-bias 5.34 5.22.3 Voltage Divider Bias 5.35 5.22.4 Fixed Bias 5.35 5.23 Biasing The MOSFET 5.36 5.23.1 Biasing of Enhancement mosfet 5.36 5.23.2 Biasing of Depletion MOSFET 5.37 5.24 The FET Model at High Frequency 5.49 5.24.1 The Common Source (CS) Amplifier at High Frequencies 5.50 5.24.2 The Common-Drain Amplifier at High Frequencies 5.53 5.25 Frequency Response oF FET Amplifier 5.54 5.26 Comparison of JFET and BJT 5.55 5.27 FET as Voltage-Variable Resistor (VVR) 5.56 5.28 Specifications of JFET and MOSFET 5.56 Review Questions 5.56 Objective Type Questions 5.58 Answers 5.63 Appendix A Specifications of Semiconductor Devices A1–A10 Appendix B Probable Value of General Physical Constants B1 Appendix C Conversion Factors and Prefixes C1 Solved Question Papers QP1.1–1.58