Low Power Analog CMOS for Cardiac Pacemakers proposes new techniques for the reduction of power consumption in analog integrated circuits. Our main example is the pacemaker sense channel, which is representative of a broader class of biomedical circuits aimed at qualitatively detecting biological signals. The first and second chapters are a tutorial presentation on implantable medical devices and pacemakers from the circuit designer point of view. This is illustrated by the requirements and solutions applied in our implementation of an industrial IC for pacemakers. There from, the book discusses the means for reduction of power consumption at three levels: base technology, power-oriented analytical synthesis procedures and circuit architecture.
1. 1 Power-dissipation trends in CMOS circuits Shrinking device geometry, growing chip area and increased data-processing speed performance are technological trends in the integrated circuit industry to enlarge chip functionality. Already in 1965 Gordon Moore predicted that the total number of devices on a chip would double every year until the 1970s and every 24 months in the 1980s. This prediction is widely known as "Moore's Law" and eventually culminated in the Semiconductor Industry Association (SIA) technology road map [1]. The SIA road map has been a guide for the in dustry leading them to continued wafer and die size growth, increased transistor density and operating frequencies, and defect density reduction. To mention a few numbers; the die size increased 7% per year, the smallest feature sizes decreased 30% and the operating frequencies doubled every two years. As a consequence of these trends both the number of transistors and the power dissi pation per unit area increase. In the near future the maximum power dissipation per unit area will be reached. Down-scaling of the supply voltage is not only the most effective way to reduce power dissipation in general it also is a necessary precondition to ensure device reliability by reducing electrical fields and device temperature, to prevent device degradation. A draw-back of this solution is an increased signal propa gation delay, which results in a lower data-processing speed performance.
This book is based on a graduate course entitled, Ubiquitous Healthcare Circuits and Systems, that was given by one of the editors at his university. It includes an introduction and overview to the field of biomedical ICs and provides information on the current trends in research. The material focuses on the design of biomedical ICs rather than focusing on how to use prepared ICs.
Low Noise Amplifiers (LNAs) are commonly used to amplify signals that are too weak for direct processing for example in radio or cable receivers. Traditionally, low noise amplifiers are implemented via tuned amplifiers, exploiting inductors and capacitors in resonating LC-circuits. This can render very low noise but only in a relatively narrow frequency band close to resonance. There is a clear trend to use more bandwidth for communication, both via cables (e.g. cable TV, internet) and wireless links (e.g. satellite links and Ultra Wideband Band). Hence wideband low-noise amplifier techniques are very much needed. Wideband Low Noise Amplifiers Exploiting Thermal Noise Cancellation explores techniques to realize wideband amplifiers, capable of impedance matching and still achieving a low noise figure well below 3dB. This can be achieved with a new noise cancelling technique as described in this book. By using this technique, the thermal noise of the input transistor of the LNA can be cancelled while the wanted signal is amplified! The book gives a detailed analysis of this technique and presents several new amplifier circuits. This book is directly relevant for IC designers and researchers working on integrated transceivers. Although the focus is on CMOS circuits, the techniques can just as well be applied to other IC technologies, e.g. bipolar and GaAs, and even in discrete component technologies.
Systematic Design of Sigma-Delta Analog-to-Digital Converters describes the issues related to the sigma-delta analog-to-digital converters (ADCs) design in a systematic manner: from the top level of abstraction represented by the filters defining signal and noise transfer functions (STF, NTF), passing through the architecture level where topology-related performance is calculated and simulated, and finally down to parameters of circuit elements like resistors, capacitors, and amplifier transconductances used in individual integrators. The systematic approach allows the evaluation of different loop filters (order, aggressiveness, discrete-time or continuous-time implementation) with quantizers varying in resolution. Topologies explored range from simple single loops to multiple cascaded loops with complex structures including more feedbacks and feedforwards. For differential circuits, with switched-capacitor integrators for discrete-time (DT) loop filters and active-RC for continuous-time (CT) ones, the passive integrator components are calculated and the power consumption is estimated, based on top-level requirements like harmonic distortion and noise budget. This unified, systematic approach to choosing the best sigma-delta ADC implementation for a given design target yields an interesting solution for a high-resolution, broadband (DSL-like) ADC operated at low oversampling ratio, which is detailed down to transistor-level schematics. The target audience of Systematic Design of Sigma-Delta Analog-to-Digital Converters are engineers designing sigma-delta ADCs and/or switched-capacitor and continuous-time filters, both beginners and experienced. It is also intended for students/academics involved in sigma-delta and analog CAD research.
LNA-ESD Co-Design for Fully Integrated CMOS Wireless Receivers fits in the quest for complete CMOS integration of wireless receiver front-ends. With a combined discussion of both RF and ESD performance, it tackles one of the final obstacles on the road to CMOS integration. The book is conceived as a design guide for those actively involved in the design of CMOS wireless receivers. The book starts with a comprehensive introduction to the performance requirements of low-noise amplifiers in wireless receivers. Several popular topologies are explained and compared with respect to future technology and frequency scaling. The ESD requirements are introduced and related to the state-of-the-art protection devices and circuits. LNA-ESD Co-Design for Fully Integrated CMOS Wireless Receivers provides an extensive theoretical treatment of the performance of CMOS low-noise amplifiers in the presence of ESD-protection circuitry. The influence of the ESD-protection parasitics on noise figure, gain, linearity, and matching are investigated. Several RF-ESD co-design solutions are discussed allowing both high RF-performance and good ESD-immunity for frequencies up to and beyond 5 GHz. Special attention is also paid to the layout of both active and passive components. LNA-ESD Co-Design for Fully Integrated CMOS Wireless Receivers offers the reader intuitive insight in the LNA’s behavior, as well as the necessary mathematical background to optimize its performance. All material is experimentally verified with several CMOS implementations, among which a fully integrated GPS receiver front-end. The book is essential reading for RF design engineers and researchers in the field and is also suitable as a text book for an advanced course on the subject.
Intelligent/smart systems have become common practice in many engineering applications. On the other hand, current low cost standard CMOS technology (and future foreseeable developments) makes available enormous potentialities. The next breakthrough will be the design and development of "smart adaptive systems on silicon" i.e. very power and highly size efficient complete systems (i.e. sensing, computing and "actuating" actions) with intelligence on board on a single silicon die. Smart adaptive systems on silicon will be able to "adapt" autonomously to the changing environment and will be able to implement "intelligent" behaviour and both perceptual and cognitive tasks. At last, they will communicate through wireless channels, they will be battery supplied or remote powered (via inductive coupling) and they will be ubiquitous in our every day life. Although many books deal with research and engineering topics (i.e. algorithms, technology, implementations, etc.) few of them try to bridge the gap between them and to address the issues related to feasibility, reliability and applications. Smart Adaptive Systems on Silicon, though not exhaustive, tries to fill this gap and to give answers mainly to the feasibility and reliability issues. Smart Adaptive Systems on Silicon mainly focuses on the analog and mixed mode implementation on silicon because this approach is amenable of achieving impressive energy and size efficiency. Moreover, analog systems can be more easily interfaced with sensing and actuating devices.
To meet the demands of today's highly competitive market, analog electronics designers must develop their IC designs in a minimum of time. The difference between first- and second-time right seriously affects a company's share of the market. Analog designers are therefore in need for structured design methods together with the theory and tools to support them, especially when pushing the performance limits in high-performance designs. Systematic Modeling and Analysis of Telecom Frontends and Their Building Blocks aims to help designers in speeding up telecommunication frontend design by offering an in-depth understanding of the frontend's behavior together with methods and algorithms that support designers in bringing this understanding to practice. The book treats topics such as time-varying phase-locked loop stability, noise in mixing circuits, oscillator injection locking, oscillator phase noise behavior, harmonic oscillator dynamics and many more. In doing so, it always starts from a theoretical foundation that is both rigorous and general. Phase-locked loop and mixer analysis, for example, are grounded upon a general framework for time-varying small-signal analysis. Likewise, analysis of harmonic oscillator transient behavior and oscillator phase noise analysis are treated as particular applications of a general framework for oscillator perturbation analysis. In order to make the book as easy to read as possible, all theory is always accompanied by numerous examples and easy-to-catch intuitive explanations. As such, the book is suited for both computer-aided design engineers looking for general theories and methods, either as background material or for practical implementation in tools, as well as for practicing circuit designers looking for help and insight in dealing with a particular application or a particular high-performance design problem.
The Analogue-to-digital converter (ADC) is the most pervasive block in electronic systems. With the advent of powerful digital signal processing and digital communication techniques, ADCs are fast becoming critical components for system’s performance and flexibility. Knowing accurately all the parameters that characterise their dynamic behaviour is crucial, on one hand to select the most adequate ADC architecture and characteristics for each end application, and on the other hand, to understand how they affect performance bottlenecks in the signal processing chain. Dynamic Characterisation of Analogue-to-Digital Converters presents a state of the art overview of the methods and procedures employed for characterising ADCs’ dynamic performance behaviour using sinusoidal stimuli. The three classical methods – histogram, sine wave fitting, and spectral analysis – are thoroughly described, and new approaches are proposed to circumvent some of their limitations. This is a must-have compendium, which can be used by both academics and test professionals to understand the fundamental mathematics underlining the algorithms of ADC testing, and as an handbook to help the engineer in the most important and critical details for their implementation.
