This text addresses the design methodologies and CAD tools available for the systematic design and design automation of analogue integrated circuits. Two complementary approaches discussed increase analogue design productivity, demonstrated throughout using design times of the different design experiments undertaken.

With the increased efforts of the analog design community to integrate analog high-frequency front-ends for telecommunications, there has been heightened interest in the behaviour of nonlinear circuits since this can cause considerable degradation of signals. In analog integrated circuits at lower frequencies, such as filters, nonlinear behaviour limits the dynamic range. Analog integrated circuit designers often lack insight into nonlinear circuit behaviour. Indeed, designers are trained to reason in linear or linearized circuits but not in nonlinear ones. Numerical circuit simulations of nonlinear circuit behavior do not provide enough insight to the designer. Distortion Analysis of Analog Integrated Circuits, with a foreword by Robert G. Meyer, provides both qualitative and quantitative insight into the nonlinear behavior of analog integrated circuits at low and high frequencies. General techniques to suppress nonlinear behavior such as pre-distortion, linear and nonlinear feedback are explained in detail and illustrated with realistic examples. In this way the book fills the gap between the theory of nonlinear systems and practical analog integrated circuits. Distortion Analysis of Analog Integrated Circuits provides the reader with an in-depth analysis of elementary transistor stages, both CMOS and bipolar, as well as an analysis of several larger circuits. Hereby use is made of advanced transistor models that are also discussed in the book. The analyses take into account many more effects than in existing publications, thanks to the use of a calculation method that yields closed-form expressions for nonlinear behavior. These expressions are interpreted and illustrated withrealistic numerical examples. Distortion Analysis of Analog Integrated Circuits is essential reading for practicing analog and mixed-signal design engineers and researchers in the field. It is also suitable as a text for an advanced course on the subject. From the foreword: I am sure that the analog circuit design community will [...] welcome this work by Dr. Wambacq and Prof. Sansen as a major contribution to the analog circuit design literature in the area of distortion analysis of electronic circuits. I am personally looking forward to having a copy readily available for reference when designing integrated circuits for communication systems.' Robert G. Meyer, Professor, Electrical Engineering and Computer Sciences, University of California, Berkeley.

Analog integrated circuits are very important as interfaces between the digital parts of integrated electronic systems and the outside world. A large portion of the effort involved in designing these circuits is spent in the layout phase. Whereas the physical design of digital circuits is automated to a large extent, the layout of analog circuits is still a manual, time-consuming and error-prone task. This is mainly due to the continuous nature of analog signals, which causes analog circuit performance to be very sensitive to layout parasitics. The parasitic elements associated with interconnect wires cause loading and coupling effects that degrade the frequency behaviour and the noise performance of analog circuits. Device mismatch and thermal effects put a fundamental limit on the achievable accuracy of circuits. For successful automation of analog layout, advanced place and route tools that can handle these critical parasitics are required. In the past, automatic analog layout tools tried to optimize the layout without quantifying the performance degradation introduced by layout parasitics. Therefore, it was not guaranteed that the resulting layout met the specifications and one or more layout iterations could be needed. In Analog Layout Generation for Performance and Manufacturability, the authors propose a performance driven layout strategy to overcome this problem. In this methodology, the layout tools are driven by performance constraints, such that the final layout, with parasitic effects, still satisfies the specifications of the circuit. The performance degradation associated with an intermediate layout solution is evaluated at runtime using predetermined sensitivities. In contrast with other performance driven layout methodologies, the tools proposed in this book operate directly on the performance constraints, without an intermediate parasitic constraint generation step. This approach makes a complete and sensible trade-off between the different layout alternatives possible at runtime and therefore eliminates the possible feedback route between constraint derivation, placement and layout extraction. Besides its influence on the performance, layout also has a profound impact on the yield and testability of an analog circuit. In Analog Layout Generation for Performance and Manufacturability, the authors outline a new criterion to quantify the detectability of a fault and combine this with a yield model to evaluate the testability of an integrated circuit layout. They then integrate this technique with their performance driven routing algorithm to produce layouts that have optimal manufacturability while still meeting their performance specifications. Analog Layout Generation for Performance and Manufacturability will be of interest to analog engineers, researchers and students.

Analog circuit design has grown in importance because so many circuits cannot be realized with digital techniques. Examples are receiver front-ends, particle detector circuits, etc. Actually, all circuits which require high precision, high speed and low power consumption need analog solutions. High precision also needs low noise. Much has been written already on low noise design and optimization for low noise. Very little is available however if the source is not resistive but capacitive or inductive as is the case with antennas or semiconductor detectors. This book provides design techniques for these types of optimization. This book is thus intended firstly for engineers on senior or graduate level who have already designed their first operational amplifiers and want to go further. It is especially for engineers who do not want just a circuit but the best circuit. Design techniques are given that lead to the best performance within a certain technology. Moreover, this is done for all important technologies such as bipolar, CMOS and BiCMOS. Secondly, this book is intended for engineers who want to understand what they are doing. The design techniques are intended to provide insight. In this way, the design techniques can easily be extended to other circuits as well. Also, the design techniques form a first step towards design automation. Thirdly, this book is intended for analog design engineers who want to become familiar with both bipolar and CMOS technologies and who want to learn more about which transistor to choose in BiCMOS.

This volume of Analog Circuit Design concentrates on three topics: Operational Amplifiers. A-to-D converters and Analog CAD. The book comprises six papers on each topic written by internationally recognised experts. These papers have a tutorial nature aimed at improving the design of analog circuits. The book is divided into three parts. Part I, Operational Amplifiers, presents new technologies for the design of Op-Amps in both bipolar and CMOS technologies. Two papers demonstrate techniques for improving frequency and gain behavior at high voltage. Low voltage bipolar Op-Amp design is treated in another paper. The realization high-speed and high gain VLSI building blocks in CMOS is demonstrated in two papers. The final paper shows how to provide output power with CMOS buffer amplifiers. Part II, Analog-to-Digital Conversion, presents papers which address very high conversion speeds and very high resolution implementations using sigma-delta modulation architectures. Analog to Digital converters provide the link between the analog world of transducers and the digital world of signal processing and computing. High-performance bipolar and MOS technologies result in high-resolution or high-speed convertors which can be applied in digital audio or video systems. Furthermore, the advanced high-speed bipolar technologies show an increase in conversion speed into the gigahertz range. Part III, Analog Computer Aided Design, presents the latest research towards providing analog circuit designers with the tools needed to automate much of the design process. The techniques and methodologies described demonstrate the advances being made in developing analog design tools comparable with those alreadyavailable for digital design. The papers in this volume are based on those presented at the Workshop on Advances in Analog Circuit Design held in Delft, The Netherlands in 1992. The main intention of the workshop was to brainstorm with a group of about 100 analog design experts on the new possibilities and future developments on the above topics. The result of this brainstorming is contained in Analog Circuit Design, which is thus an important reference for researchers and design engineers working in the forefront of analog circuit design and research.

Static and Dynamic Performance Limitations for High Speed D/A Converters discusses the design and implementation of high speed current-steering CMOS digital-to-analog converters.
Starting from the definition of the basic specifications for a D/A converter, the elements determining the static and dynamic performance are identified. Different guidelines based on scientific derivations are suggested to optimize this performance. Furthermore, a new closed formula has been derived to account for the influence of the transistor mismatch on the achievable resolution of the current-steering D/A converter. To allow a thorough understanding of the dynamic behavior, a new factor has been introduced. Moreover, the frequency dependency of the output impedance introduces harmonic distortion components which can limit the maximum attainable spurious free dynamic range. Finally, the last part of the book gives an overview on different existing transistor mismatch models and the link with the static performance of the D/A converter.

This volume of Analog Circuit Design concentrates on three topics: MOST RF Circuits; Bandpass Delta-Sigma Converters; Translinear Circuits. The book comprises six papers on each topic written by internationally recognised experts. These papers are tutorial in nature and together make a substantial contribution to improving the design of analog circuits. The book is divided into three parts: Part I, MOST RF Circuits, demonstrates the viability of using CMOS for high-frequency communication applications. This renaissance in radio-frequency design is largely driven by the explosion of interest in telecommunications and several of the papers are specifically targeted to wireless communication applications. Part II, Bandpass Delta-Sigma Converters, describes the latest developments in analog-to-digital and digital-to-analog converters. These converters find applications in telecommunications, hearing aids and audio systems, particularly when they consume low-power and have high performance. This part concludes by looking at the CAD tools required for the design of such converters. Part III, Translinear Circuits, have become important devices in building analog linear functions with variable parameters. This part of the book presents the latest research and techniques for designing Translinear Circuits using both bipolar and CMOS technologies. Analog Circuit Design is an essential reference source for analog design engineers and researchers wishing to keep abreast with the latest developments in the field. The tutorial nature of the contributions also makes it suitable for use in an advanced course.

This volume of Analog Circuit Design concentrates on three topics: RF Analog-to-Digital Converters; Sensor and Actuator Interfaces; Low-Noise Oscillators, PLLs and Synthesizers. The book comprises six papers on each topic written by internationally recognised experts. These papers are tutorial in nature and together make a substantial contribution to improving the design of analog circuits. The book is divided into three parts: Part I, RF Analog-to-Digital Converters, the application of digital techniques to process analog modulated rf signals in radio receivers requires high linearity and high-resolution analog-to-digital converters. In portable applications these converters must have an extremely low-power consumption to allow a long standby time. In low-cost signal processing applications these converters are combined with a digital signal processing system onto a single chip. Today digital signal processing systems use advanced CMOS technologies requiring the analog-to-digital converter to be implemented in the same (digital) technology. Such an implementation requires special circuit techniques. Furthermore the susceptibility of converters to ground bounce or digital noise is an important design criterion. In this part different converters and conversion techniques are described that are optimized for receiver applications. Part II, Sensor and Actuator Interfaces, interfaces for sensors and actuators shape the gates through which information is acquired from the real world into digital information systems, and vice versa. The interfaces should include analog signal conditioning, analog-to-digital conversion, digital bus interfaces and data-acquisition networks. To simplify the useof data-acquisition systems additional features should be incorporated, like self-test, and calibration. To make these goals economically feasible, these functions should be integrated, preferably with the sensor, on a single chip. This part describes the latest techniques in sensor and actuator interface design. Part III, Low-Noise Oscillators, PLLs and Synthesizers, the phase noise of the receiver's local oscillator limits the immunity against interfering signals. Therefore it has become the most important specification of the local oscillators of all integrated transceivers. Frequency synthesizers for digital tuning in portable radios require extremely low phase noise for the same reason. This part describes designs and architectures which give rise to very low phase noise. Analog Circuit Design is an essential reference source for analog design engineers and researchers wishing to keep abreast with the latest developments in the field. The tutorial nature of the contributions also makes it suitable for use in an advanced course.

Broadband opamps for multi-channel communication systems make strong demands on linearity performance. This book, written for Analog CMOS designers, presents a thorough analysis of the nonlinear behaviour of circuits, to obtain opamps with low distortion.

This volume of Analog Circuit Design concentrates on 3 topics: High-Speed Analog-to-Digital Converters, Mixed Signal Design and PLLs and Synthesizers. The book comprises 6 papers on each topic written by internationally recognized experts. These papers have a tutorial nature aimed at improving the design of analog circuits. The book is divided into 3 parts: Part I, High-Speed Analog-to-Digital Converters, describes the latest techniques for producing analog-to-digital converters for applications in disk drives, radio circuits, XDSL and super HiFi audio conversion. Converters having resolutions between 7-bit and 12-bit using CMOS techniques are presented. A 13-bit bandpass sigma-delta modulator for IF signal conversion concludes this part. Part II, Mixed Signal Design, presents papers that detail nearly all known techniques and design issues for mixed signal circuits using CAD tools. Applications for telecom, sigma-delta converters, systems-on-a-chip and RF circuitry are described. Part III, PLLs and Synthesizers, illustrates up-to-date techniques for combination of inductors on a CMOS chip together with PLL techniques to obtain low-noise frequency synthesizers for telecom applications. Special attention is paid to fractional N synthesizers using sigma-delta algorithms. Analog Circuit Design is an essential reference source for analog design engineers and researchers wishing to keep abreast with the latest developments in the field. The tutorial nature of the contributions also makes it suitable for use in an advanced design course.

Johan H. Huijsing This book contains 18 tutorial papers concentrated on 3 topics, each topic being covered by 6 papers. The topics are: Low-Noise, Low-Power, Low-Voltage Mixed-Mode Design with CAD Tools Voltage, Current, and Time References The papers of this book were written by top experts in the field, currently working at leading European and American universities and companies. These papers are the reviewed versions of the papers presented at the Workshop on Advances in Analog Circuit Design. which was held in Villach, Austria, 26-28 April 1995. The chairman of the Workshop was Dr. Franz Dielacher from Siemens, Austria. The program committee existed of Johan H. Huijsing from the Delft University of Technology, Prof.Willy Sansen from the Catholic University of Leuven, and Dr. Rudy 1. van der Plassche from Philips Eindhoven. This book is the fourth of aseries dedicated to the design of analog circuits. The topics which were covered earlier were: Operational Amplifiers Analog to Digital Converters Analog Computer Aided Design Mixed AlD Circuit Design Sensor Interface Circuits Communication Circuits Low-Power, Low-Voltage Integrated Filters Smart Power As the Workshop will be continued year by year, a valuable series of topics will be built up from all the important areas of analog circuit design. I hope that this book will help designers of analog circuits to improve their work and to speed it up.

It is a great honor to provide a few words of introduction for Dr. Georges Gielen's and Prof. Willy Sansen's book "Symbolic analysis for automated design of analog integrated circuits." The symbolic analysis method presented in this book represents a significant step forward in the area of analog circuit design. As demonstrated in this book, symbolic analysis opens up new possibilities for the development of computer-aided design (CAD) tools that can analyze an analog circuit topology and automatically size the components for a given set of specifications. Symbolic analysis even has the potential to improve the training of young analog circuit designers and to guide more experienced designers through second-order phenomena such as distortion. This book can also serve as an excellent reference for researchers in the analog circuit design area and creators of CAD tools, as it provides a comprehensive overview and comparison of various approaches for analog circuit design automation and an extensive bibliography. The world is essentially analog in nature, hence most electronic systems involve both analog and digital circuitry. As the number of transistors that can be integrated on a single integrated circuit (IC) substrate steadily increases over time, an ever increasing number of systems will be implemented with one, or a few, very complex ICs because of their lower production costs.

It is a great honor to provide an introduction for Dr. Frank Op 't Eynde's and Dr. Willy Sansen's book "Analog Interfaces for Digital Signal Processing Systems." The field of analog integrated circuit design is undergoing rapid evolution. The pervasiveness of digital processing has considerably modified the micro-system architectures: the analog part of complex mixed systems is more and more pushed at the boundary limits of the processing chain. Moreover, the increased performance of digital circuits, in terms of accuracy and speed, are making the specification requirements of analog circuits very strict. In addition to this, the technology, supply voltage and power consumption of analog circuits must be compatible with those, typical for digital circuits. Therefore, in a few words, analog circuits are becoming complex and specialised interfaces between the real world and digital signal processing domains. This technological evolution should be accompanied by an equivalently fast evolution in designer competencies. Knowledge of complicated signal handling should be quickly replaced by know-how of simple but very accurate and very fast signal processing and a solid background in data conversion techniques. All of this through the use of the CMOS (and possibly BiCMOS) technology.

High-Performance CMOS Continuous-Time Filters is devoted to the design of CMOS continuous-time filters. CMOS is employed because the most complex integrated circuits have been realized with this technology for two decades. The most important advantages and drawbacks of continuous-time filters are clearly shown. The transfer function is one of the most important filter parameters but several others (like intermodulation distortion, power-supply rejection ratio, noise level and dynamic range) are fundamental in the design of high-performance systems. Special attention is paid to the practical aspects of the design, which shows the difference between an academic design and an industrial design. A clear understanding of the behavior of the circuits and techniques is preferred over complex equations or interpretation of simulated results. Step-by-step design procedures are very often used to clarify the use of the techniques and topologies. The organization of this text is hierarchical, starting with the design consideration of the basic building blocks and ending with the design of several high-performance continuous-time filters. Most of the circuits have been fabricated, theoretically analyzed and simulated, and silicon measurement results are compared with each other. High-Performance CMOS Continuous-Time Filters can be used as a text book for senior or graduate courses on this topic and can also be useful for industrial engineers as a reference book.

This new book on Analog Circuit Design contains the revised contributions of all the tutorial speakers of the eight workshop AACD (Advances in Analog Circuit Design), which was held at Nice, France on March 23-25, 1999. The workshop was organized by Yves Leduc of TI Nice, France. The program committee consisted of Willy Sansen, K.U.Leuven, Belgium, Han Huijsing, T.U.Delft, The Netherlands and Rudy van de Plassche, T.U.Eindhoven, The Netherlands. The aim of these AACD workshops is to bring together a restricted group of about 100 people who are personally advancing the frontiers of analog circuit design to brainstorm on new possibilities and future developments in a restricted number of fields. They are concentrated around three topics. In each topic six speakers give a tutorial presentation. Eighteen papers are thus included in this book. The topics of 1999 are: (X)DSL and other communication systems RF MOST models Integrated filters and oscillators The other topics, which have been coverd before, are: 1992 Operational amplifiers A-D Converters Analog CAD 1993 Mixed-mode A+D design Sensor interfaces Communication circuits 1994 Low-power low-voltage design Integrated filters Smart power 1995 Low-noise low-power low-voltge design Mixed-mode design with CAD tools Voltage, current and time references vii viii 1996 RF CMOS circuit design Bandpass sigma-delta and other data converters Translinear circuits 1997 RF A-D Converters Sensor and actuator interfaces Low-noise oscillators, PLL's and synthesizers 1998 I-Volt electronics Design and implementation of mixed-mode systems Low-noise amplifiers and RF power amplifiers for telecommunications

Design of Low-Voltage Low-Power CMOS Delta-Sigma A/D Converters investigates the feasibility of designing Delta-Sigma Analog to Digital Converters for very low supply voltage (lower than 1.5V) and low power operation in standard CMOS processes. The chosen technique of implementation is the Switched Opamp Technique which provides Switched Capacitor operation at low supply voltage without the need to apply voltage multipliers or low VtMOST devices. A method of implementing the classic single loop and cascaded Delta-Sigma modulator topologies with half delay integrators is presented. Those topologies are studied in order to find the parameters that maximise the performance in terms of peak SNR. Based on a linear model, the performance degradations of higher order single loop and cascaded modulators, compared to a hypothetical ideal modulator, are quantified. An overview of low voltage Switched Capacitor design techniques, such as the use of voltage multipliers, low VtMOST devices and the Switched Opamp Technique, is given. An in-depth discussion of the present status of the Switched Opamp Technique covers the single-ended Original Switched Opamp Technique, the Modified Switched Opamp Technique, which allows lower supply voltage operation, and differential implementation including common mode control techniques. The restrictions imposed on the analog circuits by low supply voltage operation are investigated. Several low voltage circuit building blocks, some of which are new, are discussed. A new low voltage class AB OTA, especially suited for differential Switched Opamp applications, together with a common mode feedback amplifier and a comparator are presented and analyzed. As part of asystematic top-down design approach, the non-ideal charge transfer of the Switched Opamp integrator cell is modeled, based upon several models of the main opamp non-ideal characteristics. Behavioral simulations carried out with these models yield the required opamp specifications that ensure that the intended performance is met in an implementation. A power consumption analysis is performed. The influence of all design parameters, especially the low power supply voltage, is highlighted. Design guidelines towards low power operation are distilled. Two implementations are presented together with measurement results. The first one is a single-ended implementation of a Delta-Sigma ADC operating with 1.5V supply voltage and consuming 100 &mgr;W for a 74 dB dynamic range in a 3.4 kHz bandwidth. The second implementation is differential and operates with 900 mV. It achieves 77 dB dynamic range in 16 kHz bandwidth and consumes 40 &mgr;W. Design of Low-Voltage Low-Power CMOS Delta-Sigma A/D Converters is essential reading for analog design engineers and researchers.

This volume of Analog Circuit Design concentrates on three topics: Low-Power Low-Voltage Design; Integrated Filters, and Smart Power. The book comprises six papers on each topic written by internationally recognised experts. These papers have a tutorial nature aimed at improving the design of analog circuits. The book is divided into three parts: Part I, Low-Power Low-Voltage Design, describes the latest techniques for producing analog circuits with low-voltage low-power requirements. These circuits have an important role to play in the increasing trend towards portable products, where battery life is an important design factor. The papers cover design techniques for amplifiers, analog-to-digital converters, micro-power analog filters and medical devices. Part II, Integrated Filters, presents papers which detail nearly all known techniques to construct integrated filters. These filters all use resistors and capacitors to obtain the filtering function due to the low quality of inductors in silicon. Integration of the filtering function on chips is important to reduce system cost and provide greater accuracy. Part III, Smart Power, illustrates up-to-date techniques for implementing thermal detectors and protection networks to improve reliability and the lifetime of many analog devices. These devices are more specifically those with different analog blocks operating at different temperatures. Smart Power is thus never limited to circuit design only, but must also include packaging and cooling considerations; it is system design. Analog Circuit Design is an essential reference source for analog design engineers wishing to keep abreast with the latest developments in the field. The tutorialnature of the contributions also makes the book suitable for use in an advanced course.

This volume concentrates on three topics: mixed analog--digital circuit design, sensor interface circuits and communication circuits. The book comprises six papers on each topic of a tutorial nature aimed at improving the design of analog circuits. The book is divided into three parts. Part I: Mixed Analog--Digital Circuit Design considers the largest growth area in microelectronics. Both standard designs and ASICs have begun integrating analog cells and digital sections on the same chip. The papers cover topics such as groundbounce and supply-line spikes, design methodologies for high-level design and actual mixed analog--digital designs. Part II: Sensor Interface Circuits describes various types of signal conditioning circuits and interfaces for sensors. These include interface solutions for capacitive sensors, sigma--delta modulation used to combine a microprocessor compatible interface with on chip CMOS sensors, injectable sensors and responders, signal conditioning circuits and sensors combined with indirect converters. Part III: Communication Circuits concentrates on systems and implemented circuits for use in personal communication systems. These have applications in cordless telephones and mobile telephone systems for use in cellular networks. A major requirement for these systems is low power consumption, especially when operating in standby mode, so as to maximise the time between battery recharges.

This volume of Analog Circuit Design concentrates on three topics: Volt Electronics; Design and Implementation of Mixed-Mode Systems; Low-Noise and RF Power Amplifiers for Telecommunication. The book comprises six papers on each topic written by internationally recognised experts. These papers are tutorial in nature and together make a substantial contribution to improving the design of analog circuits. The book is divided into three parts: Part I, Volt Electronics, presents some of the circuit design challenges which are having to be met as the need for more electronics on a chip forces smaller transistor dimensions, and thus lower breakdown voltages. The papers cover techniques for 1-Volt electronics. Part II, Design and Implementation of Mixed-Mode Systems, deals with the various problems that are encountered in mixed analog-digital design. In the future, all integrated circuits are bound to contain both digital and analog sub-blocks. Problems such as substrate bounce and other substrate coupling effects cause deterioration in signal integrity. Both aspects of mixed-signal design have been addressed in this section and it illustrates that careful layout techniques embedded in a hierarchical design methodology can allow us to cope with most of the challenges presented by mixed analog-digital design. Part III, Low-noise and RF Power Amplifiers for Telecommunication, focuses on telecommunications systems. In these systems low-noise amplifiers are front-ends of receiver designs. At the transmitter part a high-performance, high-efficiency power amplifier is a critical design. Examples of both system parts are described in this section. Analog Circuit Design is an essential referencesource for analog design engineers and researchers wishing to keep abreast with the latest developments in the field. The tutorial nature of the contributions also makes it suitable for use in an advanced course.

Broadband opamps for multi-channel communication systems make strong demands on linearity performance. This book, written for Analog CMOS designers, presents a thorough analysis of the nonlinear behaviour of circuits, to obtain opamps with low distortion.

This text addresses the design methodologies and CAD tools available for the systematic design and design automation of analogue integrated circuits. Two complementary approaches discussed increase analogue design productivity, demonstrated throughout using design times of the different design experiments undertaken.

It is a great honor to provide an introduction for Dr. Frank Op 't Eynde's and Dr. Willy Sansen's book "Analog Interfaces for Digital Signal Processing Systems". The field of analog integrated circuit design is undergoing rapid evolution. The pervasiveness of digital processing has considerably modified the micro-system architectures: the analog part of complex mixed systems is more and more pushed at the boundary limits of the processing chain. Moreover, the increased performance of digital circuits, in terms of accuracy and speed, are making the specification requirements of analog circuits very strict. In addition to this, the technology, supply voltage and power consumption of analog circuits must be compatible with those, typical for digital circuits. Therefore, in a few words, analog circuits are becoming complex and specialised interfaces between the real world and digital signal processing domains. This technological evolution should be accompanied by an equivalently fast evolution in designer competencies. Knowledge of complicated signal handling should be quickly replaced by know-how of simple but very accurate and very fast signal processing and a solid background in data conversion techniques. All of this through the use of the CMOS (and possibly BiCMOS) technology.

It is a great honor to provide a few words of introduction for Dr. Georges Gielen's and Prof. Willy Sansen's book "Symbolic analysis for automated design of analog integrated circuits." The symbolic analysis method presented in this book represents a significant step forward in the area of analog circuit design. As demonstrated in this book, symbolic analysis opens up new possibilities for the development of computer-aided design (CAD) tools that can analyze an analog circuit topology and automatically size the components for a given set of specifications. Symbolic analysis even has the potential to improve the training of young analog circuit designers and to guide more experienced designers through second-order phenomena such as distortion. This book can also serve as an excellent reference for researchers in the analog circuit design area and creators of CAD tools, as it provides a comprehensive overview and comparison of various approaches for analog circuit design automation and an extensive bibliography. The world is essentially analog in nature, hence most electronic systems involve both analog and digital circuitry. As the number of transistors that can be integrated on a single integrated circuit (IC) substrate steadily increases over time, an ever increasing number of systems will be implemented with one, or a few, very complex ICs because of their lower production costs.

This book contains the revised contributions of all the speakers of the fifth AACD Workshop which was held in Lausanne on April 2-4, 1996. It was organized by Dr Vlado Valence of the EPFL University and MEAD of Lausanne. The program consisted of six tutorials per day during three days. The tutorials were presented by experts in the field. They were selected by a program committee consisting of Prof. Willy Sansen of the Katholieke Universiteit Leuven, Prof. Rudy van de Plassche of Philips Research and the University of Technology Eindhoven and Prof. 10han Huijsing of the Delft University of Technology. The three topics mentioned above have been selected because of their importance in present days analog design. The other topics that have been discussed before are: in 1992 : Operational amplifiers Analog to digital convereters Analog computer aided design in 1993 : Mixed AID cicuit design Sensor interface circuits Communication circuits in 1994 : Low-power low-voltage design Integrated filters Smart power circuits in 1995 : Low-noise, low-power, low-voltage design Mixed-mode design with CAD tools Voltage, current and time references Each AACD workhop has given rise to the publication of a book by Kluwer entitled "Analog Circuit Design". This is thus the fifth book. This series of books provides a valuable overview of all analog circuit design techniques and achievements. It is a reference for whoever is engaged in this discipline.

The analysis and prediction of nonlinear behavior in electronic circuits has long been a topic of concern for analog circuit designers. The recent explosion of interest in portable electronics such as cellular telephones, cordless telephones and other applications has served to reinforce the importance of these issues. The need now often arises to predict and optimize the distortion performance of diverse electronic circuit configurations operating in the gigahertz frequency range, where nonlinear reactive effects often dominate. However, there have historically been few sources available from which design engineers could obtain information on analysis tech niques suitable for tackling these important problems. I am sure that the analog circuit design community will thus welcome this work by Dr. Wambacq and Professor Sansen as a major contribution to the analog circuit design literature in the area of distortion analysis of electronic circuits. I am personally looking forward to hav ing a copy readily available for reference when designing integrated circuits for communication systems."