E LECTRONIC D EVICES Conventional Current Version Ninth Edition Thomas L Floyd Prentice Hall Boston Columbus Indianapolis New York San Francisco Upper Saddle River Amsterdam Cape Town Dubai London Madrid Milan Munich Paris Montreal Toronto Delhi Mexico City Sao Paulo Sydney Hong Kong Seoul Singapore Taipei Tokyo Editorial Director: Vernon Anthony Acquisitions Editor: Wyatt Morris Editorial Assistant: Yvette Schlarman Director of Marketing: David Gesell Marketing Manager: Harper Coles Marketing Assistant: Crystal Gonzales Senior Marketing Coordinator: Alicia Wozniak Senior Managing Editor: JoEllen Gohr Project Manager: Rex Davidson Senior Operations Supervisor: Pat Tonneman Art Director: Diane Ernsberger Text Designer: Ali Mohrman Media Director: Allyson Graesser Lead Media Project Manager: Karen Bretz Media Editor: Michelle Churma Composition: Aptara®, Inc Printer/Binder: Quad Graphics Cover Printer: Lehigh-Phoenix Text Font: Times Roman Credits and acknowledgments for materials borrowed from other sources and reproduced, with permission, in this textbook appear on the appropriate page within text Copyright © 2012, 2008, 2005, 2002, and 1999 Pearson Education, Inc., publishing as Prentice Hall, Lake Street, Upper Saddle River, New Jersey, 07458 All rights reserved Manufactured in the United States of America This publication is protected by Copyright, and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise To obtain permission(s) to use material from this work, please submit a written request to Pearson Education, Inc., Permissions Department, Lake Street, Upper Saddle River, New Jersey 07458 Library of Congress Cataloging-in-Publication Data Floyd, Thomas L Electronic devices : conventional current version / Thomas L Floyd.— 9th ed p cm Includes index ISBN-13: 978-0-13-254986-8 (alk paper) ISBN-10: 0-13-254986-7 (alk paper) Electronic apparatus and appliances Solid state electronics I Title TK7870.F52 2012 621.381—dc22 2010043462 10 ISBN 10: 0-13-254986-7 ISBN 13: 978-0-13-254986-8 P REFACE This ninth edition of Electronic Devices reflects changes recommended by users and reviewers Applications and troubleshooting coverage have been expanded to include several new topics related to renewable energy and automated test programming As in the previous edition, Chapters through 11 are essentially devoted to discrete devices and circuits Chapters 12 through 17 primarily cover linear integrated circuits A completely new Chapter 18 covers an introduction to programming for device testing It can be used as a “floating” chapter and introduced in conjunction with any of the troubleshooting sections Chapter 19, which was Chapter 18 in the last edition, is an online chapter that covers electronic communications Multisim® files in versions 10 and 11 are now available at the companion website, www.pearsonhighered.com/electronics New in This Edition Reorganizations of Chapters and These chapters have been significantly reworked for a more effective coverage of the introduction to electronics and diodes New topics such as the quantum model of the atom have been added GreenTech Applications This new feature appears after each of the first six chapters and introduces the application of electronics to solar energy and wind energy A significant effort is being made to create renewable and sustainable energy sources to offset, and eventually replace, fossil fuels Today’s electronics technician should have some familiarity with these relatively new technologies The coverage in this text provides a starting point for those who may pursue a career in the renewable energy field Basic Programming Concepts for Automated Testing A totally new chapter by Gary Snyder covers the basics of programming used for the automated testing of electronic devices It has become increasingly important for electronic technicians, particularly those working in certain environments such as production testing, to have a fundamental grounding in automated testing that involves programming This chapter is intended to be used in conjunction with the traditional troubleshooting sections and can be introduced or omitted at the instructor’s discretion More Multisim® Circuits Updated to Newest Versions Additional Multisim® circuit files have been added to this edition All the files have been updated to versions 10 and 11 New Format for Section Objectives The section objectives have been rewritten to provide a better indication of the coverage in each section The new format better reflects the topics covered and their hierarchy Miscellaneous Improvements An expanded and updated coverage of LEDs includes high-intensity LEDs, which are becoming widely used in many areas such as residential lighting, automotive lighting, traffic signals, and informational signs Also, the topic of quantum dots is discussed, and more emphasis is given to MOSFETs, particularly in switching power supplies IV ◆ P REFACE Standard Features ◆ Full-color format ◆ Chapter openers include a chapter outline, chapter objectives, introduction, key terms list, Application Activity preview, and website reference ◆ Introduction and objectives for each section within a chapter ◆ Large selection of worked-out examples set off in a graphic box Each example has a related problem for which the answer can be found at www.pearsonhighered.com/ electronics ◆ Multisim® circuit files for selected examples, troubleshooting, and selected problems are on the companion website ◆ Section checkup questions are at the end of each section within a chapter Answers can be found at www.pearsonhighered.com/electronics ◆ Troubleshooting sections in many chapters ◆ An Application Activity is at the end of most chapters ◆ A Programmable Analog Technology feature is at the end of selected chapters ◆ A sectionalized chapter summary, key term glossary, and formula list at the end of each chapter ◆ True/false quiz, circuit-action quiz, self-test, and categorized problem set with basic and advanced problems at the end of each chapter ◆ Appendix with answers to odd-numbered problems, glossary, and index are at the end of the book ◆ PowerPoint® slides, developed by Dave Buchla, are available online These innovative, interactive slides are coordinated with each text chapter and are an excellent tool to supplement classroom presentations Student Resources Companion Website (www.pearsonhighered.com/floyd) This website offers students an online study guide that they can check for conceptual understanding of key topics Also included on the website are the following: Chapter 19, “Electronic Communications Systems and Devices,” a table of standard resistor values, derivatives of selected equations, a discussion of circuit simulation using Multisim and NI ELVIS, and an examination of National Instruments’ LabVIEWTM The LabVIEW software is an example of a visual programming application and relates to new Chapter 18 Answers to Section Checkups, Related Problems for Examples, True/False Quizzes, CircuitAction Quizzes, and Self-Tests are found on this website Multisim® These online files include simulation circuits in Multisim® 10 and 11 for selected examples, troubleshooting sections, and selected problems in the text These circuits were created for use with Multisim® software Multisim® is widely regarded as an excellent circuit simulation tool for classroom and laboratory learning However, no part of your textbook is dependent upon the Multisim® software or provided files Laboratory Exercises for Electronic Devices, Ninth Edition, by Dave Buchla and Steve Wetterling ISBN: 0-13-25419-5 Instructor Resources To access supplementary materials online, instructors need to request an instructor access code Go to www.pearsonhighered.com/irc to register for an instructor access code Within 48 hours of registering, you will receive a confirming e-mail including an instructor access code Once you have received your code, locate your text in the online catalog and click on the Instructor Resources button on the left side of the catalog product page Select a supplement, and a login P REFACE page will appear Once you have logged in, you can access instructor material for all Prentice Hall textbooks If you have any difficulties accessing the site or downloading a supplement, please contact Customer Service at http://247.prenhall.com Online Instructor’s Resource Manual Includes solutions to chapter problems, Application Activity results, summary of Multisim® circuit files, and a test item file Solutions to the lab manual are also included Online Course Support If your program is offering your electronics course in a distance learning format, please contact your local Pearson sales representative for a list of product solutions Online PowerPoint® Slides This innovative, interactive PowerPoint slide presentation for each chapter in the book provides an effective supplement to classroom lectures Online TestGen This is a test bank of over 800 questions Chapter Features Chapter Opener Each chapter begins with an opening page, as shown in Figure P–1 The chapter opener includes a chapter introduction, a list of chapter sections, chapter objectives, key terms, an Application Activity preview, and a website reference for associated study aids ᮤ Chapter outline D IODES CHAPTER OUTLINE List of performancebased chapter objectives 2–1 2–2 2–3 2–4 2–5 2–6 2–7 2–8 2–9 2–10 ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ AND A PPLICATIONS VISIT THE COMPANION WEBSITE Diode Operation Voltage-Current (V-I) Characteristics of a Diode Diode Models Half-Wave Rectifiers Full-Wave Rectifiers Power Supply Filters and Regulators Diode Limiters and Clampers Voltage Multipliers The Diode Datasheet Troubleshooting Application Activity GreenTech Application 2: Solar Power CHAPTER OBJECTIVES ◆ ◆ Use a diode in common applications Analyze the voltage-current (V-I) characteristic of a diode Explain how the three diode models differ Explain and analyze the operation of half-wave rectifiers Explain and analyze the operation of full-wave rectifiers Explain and analyze power supply filters and regulators Explain and analyze the operation of diode limiters and clampers Explain and analyze the operation of diode voltage multipliers Interpret and use diode datasheets Troubleshoot diodes and power supply circuits Study aids and Multisim files for this chapter are available at http://www.pearsonhighered.com/electronics Website reference INTRODUCTION In Chapter 1, you learned that many semiconductor devices are based on the pn junction In this chapter, the operation and characteristics of the diode are covered Also, three diode models representing three levels of approximation are presented and testing is discussed The importance of the diode in electronic circuits cannot be overemphasized Its ability to conduct current in one direction while blocking current in the other direction is essential to the operation of many types of circuits One circuit in particular is the ac rectifier, which is covered in this chapter Other important applications are circuits such as diode limiters, diode clampers, and diode voltage multipliers A datasheet is discussed for specific diodes Introduction APPLICATION ACTIVITY PREVIEW You have the responsibility for the final design and testing of a power supply circuit that your company plans to use in several of its products You will apply your knowledge of diode circuits to the Application Activity at the end of the chapter Application Activity preview KEY TERMS ◆ Diode Bias ◆ ◆ ◆ Half-wave rectifier Peak inverse voltage (PIV) ◆ Forward bias ◆ Full-wave rectifier ◆ Reverse bias V-I characteristic DC power supply ◆ Ripple voltage Line regulation Load regulation ◆ ◆ Rectifier Filter ◆ Limiter Clamper ◆ Regulator ◆ Troubleshooting ◆ ◆ Key terms F I G U R E P– A typical chapter opener ◆ ◆ ◆ Section Opener Each section in a chapter begins with a brief introduction and section objectives An example is shown in Figure P–2 Section Checkup Each section in a chapter ends with a list of questions that focus on the main concepts presented in the section This feature is also illustrated in Figure P–2 The answers to the Section Checkups can be found at www.pearsonhighered.com/electronics Troubleshooting Sections Many chapters include a troubleshooting section that relates to the topics covered in the chapter and that illustrates troubleshooting procedures and techniques The Troubleshooting section also provides Multisim® Troubleshooting exercises A reference to the optional Chapter 18 (Basic Programming Concepts for Automated Testing) is included in each Troubleshooting section ◆ V VI ᮣ ◆ P REFACE FI G URE P–2 A typical section opener and section review Section checkup ends each section 482 FET A MPLIFIERS ◆ AND S WITCHING C IRCUITS results in conduction power losses lower than with BJTs Power MOSFETs are used for motor control, dc-to-ac conversion, dc-to-dc conversion, load switching, and other applications that require high current and precise digital control SECTION 9–6 CHECKUP Introductory paragraph begins each section 9–7 Describe a basic CMOS inverter What type of 2-input digital CMOS circuit has a low output only when both inputs are high? What type of 2-input digital CMOS circuit has a high output only when both inputs are low? T ROUBLESHOOTING A technician who understands the basics of circuit operation and who can, if necessary, perform basic analysis on a given circuit is much more valuable than one who is limited to carrying out routine test procedures In this section, you will see how to test a circuit board that has only a schematic with no specified test procedure or voltage levels In this case, basic knowledge of how the circuit operates and the ability to a quick circuit analysis are useful Performance-based section objectives After completing this section, you should be able to ❏ ❏ Reference to Chapter 18, “Basic Programming Concepts for Automated Testing” Troubleshoot FET amplifiers Troubleshoot a two-stage common-source amplifier ◆ Explain each step in the troubleshooting procedure ◆ Relate the circuit board to the schematic ◆ Use a datasheet Chapter 18: Basic Programming Concepts for Automated Testing Selected sections from Chapter 18 may be introduced as part of this troubleshooting coverage or, optionally, the entire Chapter 18 may be covered later or not at all A Two-Stage Common-Source Amplifier Assume that you are given a circuit board containing an audio amplifier and told simply that it is not working properly The circuit is a two-stage CS JFET amplifier, as shown in Figure 9–46 ᮣ FIGURE 9–46 +12 V A two-stage CS JFET amplifier circuit R2 1.5 k⍀ R5 1.5 k⍀ C3 C5 Vout C1 0.1 μ F Q1 Vin 10 μ F Q2 0.1 μ F R1 10 M⍀ R4 10 M⍀ C2 100 μ F R3 240 ⍀ R6 240 ⍀ C4 100 μ F Worked Examples, Related Problems, and Multisim® Exercises Numerous workedout examples throughout each chapter illustrate and clarify basic concepts or specific procedures Each example ends with a Related Problem that reinforces or expands on the example by requiring the student to work through a problem similar to the example Selected examples feature a Multisim® exercise keyed to a file on the companion website that contains the circuit illustrated in the example A typical example with a Related Problem and a Multisim® exercise are shown in Figure P–3 Answers to Related Problems can be found at www.pearsonhighered.com/electronics ᮣ FI G URE P–3 T HE C OMMON -S OURCE A MPLIFIER A typical example with a related problem and Multisim® exercise ◆ 463 The circuit in Figure 9–14 uses voltage-divider bias to achieve a VGS above threshold The general dc analysis proceeds as follows using the E-MOSFET characteristic equation (Equation 8–4) to solve for ID VGS = a R2 bV R1 + R2 DD ID = K(VGS - VGS(th))2 VDS = VDD - IDRD Examples are set off from text The voltage gain expression is the same as for the JFET and D-MOSFET circuits The ac input resistance is Equation 9–5 Rin ؍R1 || R2 || RIN(gate) where RIN(gate) = VGS>IGSS EXAMPLE 9–8 ᮣ A common-source amplifier using an E-MOSFET is shown in Figure 9–17 Find VGS, ID, VDS, and the ac output voltage Assume that for this particular device, ID(on) = 200 mA at VGS = V, VGS(th) = V, and gm = 23 mS Vin = 25 mV FIGURE 9–17 VDD +15 V Each example contains a related problem relevant to the example R1 4.7 M⍀ C1 RD 3.3 k⍀ C2 Vout 10 μ F Vin 0.01 μ F Solution R2 820 k⍀ VGS = a RL 33 k⍀ R2 820 kỈ bV = a b 15 V = 2.23 V R1 + R2 DD 5.52 MỈ For VGS ϭ V, K = Selected examples include a Multisim® exercise coordinated with the Multisim circuit files on the companion website ID(on) (VGS - VGS(th))2 = 200 mA = 50 mA>V2 (4 V - V)2 Therefore, ID = K(VGS - VGS(th)) = (50 mA>V 2)(2.23 V - V)2 = 2.65 mA VDS = VDD - IDRD = 15 V - (2.65 mA)(3.3 kỈ) = 6.26 V Rd = RD RL = 3.3 kỈ 33 kỈ = kỈ The ac output voltage is Vout = AvVin = gmRdVin = (23 mS)(3 kỈ)(25 mV) = 1.73 V Related Problem For the E-MOSFET in Figure 9–17, ID(on) = 25 mA at VGS = V, VGS(th) = 1.5 V, and gm = 10 mS Find VGS, ID, VDS, and the ac output voltage Vin = 25 mV Open the Multisim file E09-08 in the Examples folder on the companion website Determine ID, VDS, and Vout using the specified value of Vin Compare with the calculated values P REFACE ◆ VII Application Activity This feature follows the last section in most chapters and is identified by a special graphic design A practical application of devices or circuits covered in the chapter is presented The student learns how the specific device or circuit is used and is taken through the steps of design specification, simulation, prototyping, circuit board implementation, and testing A typical Application Activity is shown in Figure P–4 Application Activities are optional Results are provided in the Online Instructor’s Resource Manual 368 ◆ 372 P OWER A MPLIFIERS ◆ Multisim® Activity P OWER A MPLIFIERS Application Activity: The Complete PA System The class AB power amplifier follows the audio preamp and drives the speaker as shown in the PA system block diagram in Figure 7–34 In this application, the power amplifier is developed and interfaced with the preamp that was developed in Chapter The maximum signal power to the speaker should be approximately W for a frequency range of 70 Hz to kHz The dynamic range for the input voltage is up to 40 mV Finally, the complete PA system is put together Simulate the audio amplifier using your Multisim software Observe the operation with the virtual oscilloscope Prototyping and Testing Now that the circuit has been simulated, the prototype circuit is constructed and tested After the circuit is successfully tested on a protoboard, it is ready to be finalized on a printed circuit board Lab Experiment To build and test a similar circuit, go to Experiment in your lab manual (Laboratory Exercises for Electronic Devices by David Buchla and Steven Wetterling) Microphone Circuit Board DC power supply The power amplifier is implemented on a printed circuit board as shown in Figure 7–39 Heat sinks are used to provide additional heat dissipation from the power transistors Check the printed circuit board and verify that it agrees with the schematic in Figure 7–35 The volume control potentiometer is mounted off the PC board for easy access 10 Label each input and output pin according to function Locate the single backside trace Speaker Audio preamp Power amplifier (a) PA system block diagram ᮡ (b) Physical configuration F I G U RE – Heat sink The Power Amplifier Circuit The schematic of the push-pull power amplifier is shown in Figure 7–35 The circuit is a class AB amplifier implemented with Darlington configurations and diode current mirror bias Both a traditional Darlington pair and a complementary Darlington (Sziklai) pair are used to provide sufficient current to an Ỉ speaker load The signal from the preamp is ᮣ FIGURE 7–35 Link to experiment in lab manual Printed circuit board +15 V Class AB power push-pull amplifier R2 k⍀ Q1 2N3904 Q2 D1 BD135 D2 Output Q3 ᮡ D3 2N3906 R1 150 k⍀ FI G UR E 7– 39 Power amplifier circuit board Input Q5 Q4 2N3904 BD135 R3 220 ⍀ Troubleshooting the Power Amplifier Board A power amplifier circuit board has failed the production test Test results are shown in Figure 7–40 11 Based on the scope displays, list possible faults for the circuit board Putting the System Together –15 V ᮡ The preamp circuit board and the power amplifier circuit board are interconnected and the dc power supply (battery pack), microphone, speaker, and volume control potentiometer are attached, as shown in Figure 7–41 12 Verify that the system interconnections are correct F IGURE P–4 Portion of a typical Application Activity section GreenTech Application Inserts These inserts are placed after each of the first six chapters to introduce renewable energy concepts and the application of electronic devices to solar and wind technologies Figure P–5 illustrates typical GreenTech Application pages Chapter End Matter chapters: The following pedagogical features are found at the end of most ◆ Summary ◆ Key Term Glossary ◆ Key Formulas ◆ True/False Quiz ◆ Circuit-Action Quiz ◆ Self-Test ◆ Basic Problems ◆ Advanced Problems ◆ Datasheet Problems (selected chapters) ◆ Application Activity Problems (many chapters) ◆ Multisim® Troubleshooting Problems (most chapters) Simulations are provided for most Application Activity circuits VIII ◆ P REFACE 224 ◆ G REEN T ECH A PPLIC ATION B IPOL AR J UNCTION T RANSISTORS GreenTech Application 4: Solar Power ◆ 225 daily east-to-west movement This is particularly important with concentrating collectors that need to be oriented correctly to focus the sun on the active region Figure GA4–2 is an example showing the improvement in energy collection of a typical tracking panel versus a nontracking panel for a flat solar collector As you can see, tracking extends the time that a given output can be maintained In this GreenTech Application, solar tracking is examined Solar tracking is the process of moving the solar panel to track the daily movement of the sun and the seasonal changes in elevation of the sun in the southern sky The purpose of a solar tracker is to increase the amount of solar energy that can be collected by the system For flat-panel collectors, an increase of 30% to 50% in collected energy can be realized with sun tracking compared to fixed solar panels ᮣ F IG U R E G A – Relative output voltage Graphs of voltages in tracking and nontracking (fixed) solar panels Tracking Panel’s rated current Before looking at methods for tracking, let’s review how the sun moves across the sky The daily motion of the sun follows the arc of a circle from east to west that has its axis pointed north near the location of the North Star As the seasons change from the winter solstice to the summer solstice, the sun rises a little further to the north each day Between the summer solstice and the winter solstice, the sun moves further south each day The amount of the north-south motion depends on your location Nontracking Time of day 10 11 12 Single-Axis Solar Tracking There are several methods of implementing solar tracking Two main ones are sensor controlled and timer controlled For flat-panel solar collectors, the most economical and generally most practical solution to tracking is to follow the daily east-west motion, and not the annual north-south motion The daily east-to-west motion can be followed with a single-axis tracking system There are two basic single-axis systems: polar and azimuth In a polar system, the main axis is pointed to the polar north (North Star), as shown in Figure GA4–1(a) (In telescope terminology, this is called an equatorial mounting.) The advantage is that the solar panel is kept at an angle facing the sun at all times because it tracks the sun from east to west and is angled toward the southern sky In an azimuth tracking system, the motor drives the solar panel and frequently multiple panels The panels can be oriented horizontally but still track the east-to-west motion of the sun Although this does not intercept as much of the sunlight during the seasons, it has less wind loading and is more feasible for long rows of solar panels Figure GA4–1(b) shows a solar array that is oriented horizontally with the axis pointing to true north and uses azimuth tracking (east to west) As you can see, sunlight will strike the polar-aligned panel more directly during the seasonal movement of the sun than it will with the horizontal orientation of the azimuth tracker Polar North (North Star) West Electric motor turns the panels Sensor-Controlled Solar Tracking This type of tracking control uses photosensitive devices such as photodiodes or photoresistors Typically, there are two light sensors for the azimuth control and two for the elevation control Each pair senses the direction of light from the sun and activates the motor control to move the solar panel to align perpendicular to the sun’s rays Figure GA4–3 shows the basic idea of a sensor-controlled tracker Two photodiodes with a light-blocking partition between them are mounted on the same plane as the solar panel SUN SUN Photodiodes True North Solar panel East Lower output Higher output West Position control circuits East (a) A single-axis polar-aligned tracker ᮡ (b) Single-axis azimuth tracker F IGU RE G A4 – Output rotates motor Types of single-axis solar tracking (a) Outputs of the photodiodes are unequal if solar panel is not directly facing the sun Some solar tracking systems combine both the azimuth and the elevation tracking, which is known as dual-axis tracking Ideally, the solar panel should always face directly toward the sun so that the sun light rays are perpendicular to the panel With dual-axis tracking, the annual north-south motion of the sun can be followed in addition to the ᮡ ᮡ (b) Outputs of the photodiodes are equal when solar panel orientation is optimum F IG U R E G A – Simplified illustration of a light-sensing control for a solar-tracking system Relative sizes are exaggerated to demonstrate the concept FIG UR E P – Portion of a typical GreenTech Application Suggestions for Using This Textbook As mentioned, this book covers discrete devices and circuits in Chapters through 11 and linear integrated circuits in Chapters 12 through 17 Chapter 18 introduces programming concepts for device testing and is linked to Troubleshooting sections Option (two terms) Chapters through 11 can be covered in the first term Depending on individual preferences and program emphasis, selective coverage may be necessary Chapters 12 through 17 can be covered in the second term Again, selective coverage may be necessary Option (one term) By omitting certain topics and by maintaining a rigorous schedule, this book can be used in one-term courses For example, a course covering only discrete devices and circuits would use Chapters through 11 with, perhaps, some selectivity Similarly, a course requiring only linear integrated circuit coverage would use Chapters 12 through 17 Another approach is a very selective coverage of discrete devices and circuits topics followed by a limited coverage of integrated circuits (only op-amps, for example) Also, elements such as the Multisim exercises, Application Activities, and GreenTech Applications can be omitted or selectively used To the Student When studying a particular chapter, study one section until you understand it and only then move on to the next one Read each section and study the related illustrations carefully; think about the material; work through each example step-by-step, work its Related Problem and check the answer; then answer each question in the Section Checkup, and check your answers Don’t expect each concept to be completely clear after a single reading; you may have to read the material two or even three times Once you think that you understand the material, review the chapter summary, key formula list, and key term definitions at the end of the ... important for electronic technicians, particularly those working in certain environments such as production testing, to have a fundamental grounding in automated testing that involves programming This... covers discrete devices and circuits in Chapters through 11 and linear integrated circuits in Chapters 12 through 17 Chapter 18 introduces programming concepts for device testing and is linked to Troubleshooting... increasing the number of free electrons or holes to increase its conductivity and make it useful in electronic devices This is done by adding impurities to the intrinsic material Two types of extrinsic