Op Amp Applications Handbook
Op Amp Applications HandbookThis page intentionally blankOp Amp applications HandbookANALOGDEVICESlalt Jung, Editorwith the technical staff of Analog devicesA Volume in the Analog Devices SeriesAMSTERDAM● BOSTON● HEIDELBERO· LONDONNEW YORK· OXFORD● PARIS● SAN DIEGOSAN FRANCISCO· SINGAPORE● SYDNEY● TOKYOELSEVIERNewnes is an imprint of elsevierNewnesNewnes is an imprint of elsevier30 Corporate Drive, Suite 400, Burlington, MA O1803, USALinacre house. Jordan hill. Oxford OX2 8DP UKCopyright o 2005 by Analog Devices, Inc. All rights reservedNo part of this publication may be reproduced, stored in a retrieval system, ortransmitted in any form or by any means, electronic, mechanical, photocopying,recording, or otherwise, without the prior written permission of the publisherPermissions may be sought directly from elseviers science Technology rightsDepartment in Oxford, UK: phone: (+44)1865843830, fax: (+44)1865 853333e-mail:permissions@elsevier.com.uk.Youmayalsocompleteyourrequeston-lineviatheElsevierhomepage(http:/elsevier.com),byselecting"customerSupport' and then“ Obtaining Permissions.”a Recognizing the importance of preserving what has been written, ElsevierS prints its books on acid-free paper whenever possibleLibrary of Congress Cataloging-in-Publication DataJung, Water G.Op Amp applications handbook /by Walt Jungp. cm-(Analog Devices series)ISBN0-7506-7844-51. Operational amplifiers--Handbooks, manuals, etc. I. Title. II. SeriesTK7871.5806185152004621.395-dc222004053842British Library Cataloguing-in-Publication DataA catalogue record for this book is available from the british libraryFor information on all Newnes publicationsvisitourwebsiteatwww.bookselsevier.com04050607080910987654321Printed in the united states of americaContentsrewordPreface…Acknowledgments..p Amp History HighlightsChapter1:印 p Amp basics……Section 1-1: IntroductionSection 1-2: Op Amp Topologies23Section 1-3: Op Amp StructuresSection 1-4: Op Amp SpecificationsSection1-5: Precision○ P Amps…………89Section 1-6: High Speed Op Amps.97Chapter2: Specialty Amplifiers…………………121Section2-1: Instrumentation Amplifiers……123Section 2-2: Programmable Gain Amplifiers151Section2-3: Isolation Amplifiers.……….161Chapter3: Using OP Amps with Data Converters………173Section 3-1: Introduction173Section3-2:ADC/ DAC Specifications……..179Section3-3: Driving ADC Inputs…………..193Section3-4: Driving ADO/ DAC Reference Inputs………213Section 3-5: Buffering DAC Outputs217Chapter4: Sensor Signal Conditioning……………….227Section 4-1: Introduction .........................................................................................227Section 4-2: Bridge Circuits.231Section 4-3: Strain. Force Pressure and flow measurements247Section 4-4: High Impedance Sensors..257Section 4-5: Temperature sensors申鲁285Chapter5: Analog Filters…………………………………….309Section 5-1: Introduction .............................................309Section 5-2. The transfer function313ContentsSection 5-3: Time Domain Response323Section 5-4: Standard Responses325Section 5-5: Frequency Transformations349Section 5-6: Filter realizations357Section 5-7: Practical Problems in Filter Implementation393Section 5-8: Design Examples403Chapter6: Signal Amplifiers……………………423Section 6-1: Audio amplifiers423Section 6-2: Buffer Amplifiers and Driving Capacitive Loads.493Section 6-3: Video Amplifiers∴505Section 6-4: Communication AmplifiersSection 6-5: Amplifier ldeas567Section 6-6: Composite Amplifiers587Chapter 7: Hardware and Housekeeping Techniques607Section 7-1: Passive Components.609Section 7-2: PCB Design Issues629Section73: Op Amp Power Supply Systems……∴653Section 7-4: Op Amp Protection.675Section 7-5: Thermal Considerations.699Section 7-6: EMI/RFI Considerations.................707Section 7-7: Simulation, Breadboarding and prototypir737Chapter8:0 p Amp History……765Section 8-1: Introduction767Section 8-2: Vacuum Tube Op Amps773Section 8-3: Solid-State Modularand Hybrid Op Amps791Section 8-4: IC Op Amps.805ndex831ForewordThe signal-processing products of Analog Devices, InC(ADD), along with those of its worthy competitors,have always had broad applications, but in a special way: they tend to be used in critical roles making possible--and at the same time limiting-the excellence in performance of the device, instrument, apparatusor system using themThink about the op amp--how it can play a salient role in amplifying an ultrasound wave from deep withina human body, or measure and help reduce the error of a feedback system; the data converter-and itscritical position in translating rapidly and accurately between the world of tangible physics and the world ofabstract digits; the digital signal processor--manipulating the transformed digital data to extract informa-tion, provide answers and make crucial instant-by-instant decisions in control systems; transducers, suchas the life-saving MEMs accelerometers and gyroscopes; and even control chips, such as the one thatempowers the humble thermometric junction placed deep in the heart of a high-performance--but veryvulnerable---microcomputer chipFrom its founding two human generations ago, in 1965, ADI has been committed to a leadership role indesigning and manufacturing products that meet the needs of the existing market, anticipate the near-termneeds of present and future users, and envision the needs of users yet unknown-and perhaps unborn--whowill create the markets of the future. These existing, anticipated and envisioned"needs"must perforceinclude far more than just the design, manufacture and timely delivery of a physical device that performs afunction reliably to a set of specifications at a competitive priceWe've always called a product that satisfies these needs the augmented product, but what does this mean?The physical product is a highly technological product that, above all, requires knowledge of its possibili-ties, limitations and subtleties. But when the earliest generations--and to some extent later generations--ofsuch a product appear in the marketplace, there exist few(if any) school courses that have produced graduates proficient in its use. There are few knowledgeable designers who can foresee its possibilities. So wehave the huge task of creating awareness; teaching about principles, performance measures, and existinapplications; and providing ideas to stimulate the imagination of those creative users who will provide ournext round of challengesThis problem is met by deploying people and publications. The people are Applications Engineers, who candeal with user questions arriving via phone, fax, and e-mail-as well as working with users in the field tosolve particular problems. These experts also spread the word by giving seminars to small and large groupsfor purposes from inspiring the creative user to imbuing the system, design, and components engineer withthe nuts-and-bolts of practice. The publications-both in hard copy and on-line--range from authoritativehandbooks, such as the present volume, comprehensive data sheets, application notes, hardware and softare manuals, to periodic publications, such as "Solutions Bulletins "and our unique Analog dialogue-thesole survivor among its early peers--currently in its 38th year of continuous publication in print and its 6thyear of regular publication on the InternetThis book is the ultimate expression of product augmentation"as it relates to operational amplifiers. Insome senses, it can be considered a descendant of two early publications. The first is a 1965 set of Op AmpForewordNotes(Parts 1, 2, 3, and 4), written by Analog Devices co-founder Ray Stata, with the current text directlyrefecting these roots much less directly would be the 1974 first edition of the Ic op amp cookbook byWalter Jung. although useful earlier books had been published by burr-Brown, and by dan Sheingold atPhilbrick, these two timely publications were seminal in the early days of the silicon era, advocating the un-derstanding and use of ic op amps to a market in the process of growing explosively. Finally, and perhapsmore important to current students of the op amp art, would be the countless contributions of adi designand applications engineers, amassed over the years and so highly evident within this new bookOperational amplifiers have been marketed since 1953, and practical IC op amps have been available sincethe late 1960s. Yet, half a century later, there is still a need for a book that embraces the many aspects of opamp technology-one that is thorough in its technical content, that looks forward to tomorrow's uses andback to the principles and applications that still make op amps a practical necessity today. We believe thatthis is such a book, and we commend Walter Jung for"augmenting" the op amp in such an interesting andaccessible formRay stataDaniel rheingoldNorwood, Massachusetts, April 28, 2004PrefaceOp Amp applications Handbook is another book on the operational amplifier, or op amp. As the nameimplies, it covers the application of op amps, but does so on a broader scope Thus it would be incorrect toassume that this book is simply a large collection of app notes on various devices, as it is far more than thatAny IC manufacturer in existence since the 1960s has ample application data on which to draw. In this case,however, Analog Devices, Inc has had the benefit of applications material with a history that goes backbeyond early iC developments to the preceding period of solid-state amplifiers in modular form, with linksto the even earlier era of vacuum tube op amps and analog computers, where the operational amplifier beganThis book brings some new perspectives to op amp applications. It adds insight into op amp origins andhistorical developments not available elsewhere. Within its major chapters it also offers fundamentaldiscussions of basic op amp operation; the roles of various device types (including both op amps and otherspecialty amplifiers, such as instrumentation amplifiers); the procedures for optimal interfacing to othersystem components such as ADCs and DACs, signal conditioning and filtering in data processing systemsand a wide variety of signal amplifiers The book concludes with practical discussions of various hardwareissues, such as passive component selection, printed circuit design, modeling and breadboarding, etc. Inshort, while this book does indeed cover op amp applications, it also covers a host of closely related designtopics, making it a formidable toolkit for the analog designerThe book is divided into 8 major chapters, and occupies nearly 1000 pages, including index. The chaptersare outlined as followsChapter 1, Op amp basics, has five sections authored by james bryant. Walt Jung, and walt Kester. Thischapter provides fundamental op amp operating information. An introductory section addresses their idealand non-ideal characteristics along with basic feedback theory. It then spans op amp device topologiesincluding voltage and current feedback models, op amp internal structures such as input and/or outputarchitectures, the use of bipolar and/or FET devices, single supply/dual supply considerations, and op ampdevice specifications that apply to all types. The two final sections of this chapter deal with the operatingcharacteristics of precision and high-speed op amp types. This chapter, itself a book-within-a-book, occupies about 11 8 pagesChapter 2, Specialty Amplifiers, has three sections authored by Walt Kester, Walt Jung, and James BryantThis chapter provides information on those commonly used amplifier types that use op amp-like principlesbut aren't op amps themselves--instead they are specialty amplifiers. The first section covers the design andapplication of differential input, single-ended output amplifiers, known as instrumentation amplifiers. Thesecond section is on programmable gain amplifiers, which are op amp or instrumentation amplifier stages,designed to be dynamically addressable for gain. The final section of the chapter is on isolation amplifiers,which provide galvanic isolation between sections of a system. This chapter occupies about 52 pagesChapter 3, Using Op Amps with Data Converters, has five sections authored by Walt Kester, James Bryant,and Paul Hendriks. The first section is an introductory one, introducing converter terms and the conceptof minimizing conversion degradation within the design of an op amp interface. The second section covers ADC and DAC specifications, including such critically important concepts as linearity, monotonicity