CMOS Voltage References E-Book

Chi-Wah Kok

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Serie: Wiley - IEEE
• Sprache: Englisch

Seitenzahl: 491

Veröffentlichungsjahr: 2012

Beschreibung

A practical overview of CMOS circuit design, this book covers the technology, analysis, and design techniques of voltage reference circuits. The design requirements covered follow modern CMOS processes, with an emphasis on low power, low voltage, and low temperature coefficient voltage reference design. Dedicating a chapter to each stage of the design process, the authors have organized the content to give readers the tools they need to implement the technologies themselves. Readers will gain an understanding of device characteristics, the practical considerations behind circuit topology, and potential problems with each type of circuit. Many design examples are used throughout, most of which have been tested with silicon implementation or employed in real-world products. This ensures that the material presented relevant to both students studying the topic as well as readers requiring a practical viewpoint. * Covers CMOS voltage reference circuit design, from the basics through to advanced topics * Provides an overview of basic device physics and different building blocks of voltage reference designs * Features real-world examples based on actual silicon implementation * Includes analytical exercises, simulation exercises, and silicon layout exercises, giving readers guidance and design layout experience for voltage reference circuits * Solution manual available to instructors from the book's companion website This book is highly useful for graduate students in VLSI design, as well as practicing analog engineers and IC design professionals. Advanced undergraduates preparing for further study in VLSI will also find this book a helpful companion text.

Leseprobe

Contents

Cover

Title Page

Copyright

About the Authors

Preface

Acknowledgements

Nomenclature

Chapter 1: Warm Up

1.1 Bipolar Junction Transistors

1.2 Metal–Oxide Semiconductor Field–Effect Transistor

1.3 Diode

1.4 Resistor

1.5 Device Matching

1.6 Simulation Models for Circuit Design

1.7 Noise

1.8 Fabrication Technology

1.9 Book Organization

1.10 Exercises

References

Chapter 2: Voltage Reference

2.1 Performance Measures

2.2 Other Design Considerations

2.3 Summary

2.4 Exercises

References

Chapter 3: Bandgap Voltage Reference

3.1 Widlar Bandgap Voltage Reference Circuit

3.2 Drain Voltage Equalization Current Mirror

3.3 Major Circuit Elements

3.4 Complete Layout

3.5 Summary

3.6 Exercises

References

Chapter 4: Error Sources in Bandgap Voltage Reference Circuit

4.1 Non-Ideal Opamp

4.2 Current Mirror Mismatch

4.3 Bipolar Transistor

4.4 Resistor Variation

4.5 Power Supply Variation

4.6 Output Loading

4.7 Output Noise

4.8 Voltage Reference Circuit Trimming

4.9 Summary

4.10 Exercises

References

Advanced Voltage Reference Circuits

Chapter 5: Temperature Compensation Techniques

5.1 VBE – Δ VBE Compensation

5.2 Widlar PTAT Current Source and VBE Compensation

5.3 VGS Based Temperature Compensation

5.4 Summary

5.5 Exercises

References

Chapter 6: Sub–1V Voltage Reference Circuit

6.1 Sub–1V Output Stage

6.2 Voltage Headroom in Opamp Based β –multiplier Voltage Reference Circuit

6.3 Sub–1V Bandgap Voltage Reference by Resistive Division

6.4 Peaking Current Source and VBE Compensation

6.5 Weighted Δ VGS Compensation

6.6 Summary

6.7 Exercises

References

Chapter 7: High Order Curvature Correction

7.1 Compensation Order

7.2 Second Order Temperature Compensation

7.3 BJT Current Subtraction

7.4 Piecewise Linear Compensation

7.5 Sum and Difference of Sources with Similar Temperature Dependence

7.6 Summary

7.7 Exercises

References

Chapter 8: CMOS Voltage Reference without Resistors

8.1 Generation of Weighted PTAT Source By Inverse Functions

8.2 Resistorless Voltage and Current Sources

8.3 First Order Compensated Resistorless Bandgap Voltage Reference Circuit

8.4 Resistorless Sub-Bandgap Reference Circuit

8.5 Summary

References

A: SPICE Model File

B: SPICE Netlist of Voltage Reference Circuit

Index

This edition first published 2013 © 2013 John Wiley & Sons Singapore Pte. Ltd.

Registered officeJohn Wiley & Sons Singapore Pte. Ltd., 1 Fusionopolis Walk, #07-01 Solaris South Tower, Singapore 138628

For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com.

All Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as expressly permitted by law, without either the prior written permission of the Publisher, or authorization through payment of the appropriate photocopy fee to the Copyright Clearance Center. Requests for permission should be addressed to the Publisher, John Wiley & Sons Singapore Pte. Ltd., 1 Fusionopolis Walk, #07-01 Solaris South Tower, Singapore 138628, tel: [phone], fax: [phone], email: [email protected].

Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books.

Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The Publisher is not associated with any product or vendor mentioned in this book. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the Publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought.

Library of Congress Cataloging-in-Publication Data

CMOS voltage references : an analytical and practical perspective / Chi-Wah Kok, Wing-Shan Tam. - First edition. pages cm Includes bibliographical references and index. ISBN 978-1-118-27568-9 (hardback) 1. Voltage references. 2. Electric circuit analysis. 3. Electric circuits-Design and construction. I. Kok, Chi-Wah. II. Tam, Wing-Shan. III. Title: Voltage reference. TK454.C628 2013 621.3815′28-dc23 2012030274

ISBN: 9781118275689

ABOUT THE AUTHORS

Chi-Wah Kok was born in Hong Kong. He was granted a PhD degree from the University of Wisconsin Madison. Since 1992, he has been working with various semiconductor companies, research institutions, and universities, which include AT & T Labs Research, Holmdel, SONY U.S. Research Labs, Stanford University, Hong Kong University of Science and Technology, Hong Kong Polytechnic University, City University of Hong Kong, Lattice Semiconductor, etc. In 2006, he founded Canaan Microelectronics Corp Ltd., a fabless IC company with products in mixed signal IC for consumer electronics. Dr. Kok embraces new technologies to meet the fast changing market requirements. He has extensively applied signal processing techniques to improve the circuit topologies, designs, and fabrication technologies within Canaan. This includes the application of semidefinite programming to circuit design optimization, abstract algebra in switched capacitor circuit topologies improvement, and nonlinear optimization methods to optimize high voltage MOSFET layout and fabrication.

Wing-Shan Tam was born in Hong Kong. She received her BEng degree in electronic engineering from The Chinese University of Hong Kong, MSc degree in electronic and information engineering from The Hong Kong Polytechnic University, and PhD degree in electronic engineering from the City University of Hong Kong in 2004, 2007, and 2011, respectively. Currently, she is the Engineering Manager of Canaan Microelectronics Corp Ltd. Her research interests include mixed-signal integrated circuit design for data conversion and power-management.

PREFACE

This book has a genesis: It started as internal training material for engineers working in Canaan Microelectronics Corp. Ltd. It is also a monograph because it presents the outcome of our research and teaching activities in the field of temperature independent circuit design at both the Canaan Microelectronics Corp. Ltd. and the City University of Hong Kong. Many unpublished works are included in this book. Numerous design examples are also presented together with detailed discussions on design principles, performance analysis, and the potential problems of each circuit topology. This book is intended to be course material for senior and graduate level courses, training material for engineers, and also a reference text for readers who are working in the field of temperature independent circuit design.

The book is divided into eight chapters. The first chapter offers an introduction of device physics focusing on the temperature properties of individual devices, which introduces just enough material for voltage reference circuit design and analysis. Details of general device physics may be gathered from existing literature, such as the textbooks by Chenming C. Hu, (Modern Semiconductor Devices for Integrated Circuits, Prentice Hall, 2010), and S.M. Sze, (Physics of Semiconductor Devices, Wiley, 1969) that offer detailed discussions on the device physics for bipolar transistors, MOS transistors, and other passive components manufactured in the CMOS process. Besides the physics, towards the end of Chapter 1, we also discuss practical issues in CMOS circuit design. The device matching problem is introduced. Computer simulation for circuit design with process variations is discussed. Finally, the device noise models that describe the noises associated with CMOS devices are presented. Chapter 2 presents the performance characterization of voltage reference circuits. The presented characterization will be used throughout the book in the analytical discussions and performance comparisons of individual voltage reference circuits. A general voltage reference circuit framework of opamp based β-multiplier bandgap voltage reference is presented in Chapter 3. The presented voltage reference circuit is silicon proven, and has been applied to a power management IC of Canaan Microelectronics Corp. Ltd.: the micrograph of the die is shown on the front page of this book. Every building block within the voltage reference circuit is discussed analytically together with layout details. Various error sources of the circuit are identified, and analyzed in Chapter 4. Methods to remedy each problem together with their pros and cons are discussed in detail in Chapter 4. The basic PTAT-CTAT temperature compensation technique discussed in Chapter 4 will be extended to voltage reference circuits using various temperature dependent devices and topologies in Chapter 5. Analytical derivation to determine the component values of each device within the voltage reference circuit, together with the important design considerations of each circuit and topology will be discussed. Chapter 6 discusses the design of voltage reference circuits with sub-1V supply, and voltage reference circuits with sub-1V reference voltage. Notice that the design of the voltage reference circuit with a sub-1V reference voltage is different from that of the voltage reference circuit with a sub-1V supply voltage. A voltage reference circuit with a sub-1V supply voltage is also a voltage reference circuit with a sub-1V reference voltage. The voltage reference circuit with sub-1V reference voltage being able to operate with a sub-1V supply voltage is important in modern CMOS circuit design where the supply voltage keeps reducing for power reduction and silicon size shrinkage. A number of sub-1V voltage reference circuits will be discussed in this chapter.

High order curvature compensated voltage reference circuits are presented in Chapter 7, which are important to applications that require a reference voltage with low temperature sensitivity. A number of high accuracy voltage reference circuit topologies, including high order curvature compensation, inverted temperature compensation, and piecewise temperature compensation etc. are discussed. This book concludes in Chapter 8 with a discussion on a type of special voltage reference circuit that does not require resistors. Such a voltage reference circuit has the advantage of compact layout. The performance of a resistor free voltage reference circuit can be further optimized with applications of piecewise temperature compensation technique to lower the temperature sensitivity of the circuit. Post-fabrication trimming circuits are discussed to reduce the reference voltage variation.

A detailed summary of the state of the art development with respect to the topic of each chapter is presented in the “Summary” section of each chapter. Homework problems are presented in the “Exercise” section in individual chapter. The homework includes both analytic problems, and SPICE based computer simulation exercises. While the process parameters used in this book and also in developing the exercises may not be the same as those in your institution, it is our hope that the exercises will provide you with general guidelines, analysis, design and layout experience for the design of the voltage reference circuits with the help of SPICE. The experience will further address the performance evaluation of the voltage reference circuit which will help you to achieve a thorough consideration of the voltage reference circuit before the actual design.

The development of voltage reference circuits is still continuing and therefore a book, such as this one, cannot be definitive or complete. It is hoped, however, that this book will fill an important gap; students embarking upon mixed-signal circuit design should be able to learn sufficient basics before tackling journal papers, researchers and engineers in the field of temperature independent/dependent circuit design should be able to use it as reference to assist their circuit design tasks, and current researchers in the field should be able to get a broad perspective on what has been achieved. The subject area is introduced, some major developments are recorded, and enough successes as well as challenges are noted here for readers to look into other voltage independent/dependent circuit design problems and generate solutions for their own problems.

Chi-Wah Kok and Wing-Shan Tam February 2012

ACKNOWLEDGEMENTS

We are in debt to many people, too numerous to mention. To all the scholars who have influenced us, both in person or through their works, we acknowledge our indebtedness and express our great appreciation. Perhaps the most noteworthy was Prof. Hei Wong of the City University of Hong Kong whose knowledge, enthusiasm in advanced microelectronics research and development, and generous support in the course of the development of this book has surely inspired and greatly assisted us. We are proud to say that Prof. Wong is one of our greatest role models.

Dr. Kok would like to take this chance to claim victory in the competition with his wife Dr. Annie Ko on who will be the first to complete his/her second textbook. It was this competition that provided Dr. Kok with the extra boost to get this book finished with his best effort. Dr. Kok is also very happy to collaborate with Dr. Tam on this book project, who has always been his best collaborator in both the academic and business spheres. Dr. Tam is truly indebted and grateful to her parents, Simon Tam and Gloria Lee, for their love, encouragement, and their constant support in all her pursuits, including her PhD study and the completion of this book. Dr. Tam would also like to thank her beloved family, especially her sister and grandmother, who are always willing to share her stress and happiness. Finally, Dr. Tam would like to express her sincere gratitude to Dr. Kok, who introduced her into the world of IC design. Dr. Tam is very grateful for the opportunity to coauthor this book and treasures other aspects of her partnership with Dr. Kok too. Coauthoring a book is never easy. In the course of the development of this book, the authors have learned a lot from each other, and adapted to each others’ working and learning styles. We are looking forward to seeing our excellent partnership extend to future book and other research and development projects.

Despite the assistance, review, overseeing, and editing of so many people, we have no doubt that errors still lurk undetected. These are ours alone, and it is our hope that the reader of this book will discover them and bring them to our attention, so that they all may be eradicated.

Chi-Wah Kok and Wing-Shan Tam