Author: Vincenzo Peluso
Publisher: Springer Science & Business Media
ISBN: 1475729782
Category : Technology & Engineering
Languages : en
Pages : 178
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Book Description
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 a systematic 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.
Author: Qunying Li
Publisher:
ISBN:
Category :
Languages : en
Pages : 171
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Book Description
Author: Shahriar Rabii
Publisher: Springer Science & Business Media
ISBN: 1461551056
Category : Technology & Engineering
Languages : en
Pages : 198
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Book Description
Oversampling techniques based on sigma-delta modulation are widely used to implement the analog/digital interfaces in CMOS VLSI technologies. This approach is relatively insensitive to imperfections in the manufacturing process and offers numerous advantages for the realization of high-resolution analog-to-digital (A/D) converters in the low-voltage environment that is increasingly demanded by advanced VLSI technologies and by portable electronic systems. In The Design of Low-Voltage, Low-Power Sigma-Delta Modulators, an analysis of power dissipation in sigma-delta modulators is presented, and a low-voltage implementation of a digital-audio performance A/D converter based on the results of this analysis is described. Although significant power savings can typically be achieved in digital circuits by reducing the power supply voltage, the power dissipation in analog circuits actually tends to increase with decreasing supply voltages. Oversampling architectures are a potentially power-efficient means of implementing high-resolution A/D converters because they reduce the number and complexity of the analog circuits in comparison with Nyquist-rate converters. In fact, it is shown that the power dissipation of a sigma-delta modulator can approach that of a single integrator with the resolution and bandwidth required for a given application. In this research the influence of various parameters on the power dissipation of the modulator has been evaluated and strategies for the design of a power-efficient implementation have been identified. The Design of Low-Voltage, Low-Power Sigma-Delta Modulators begins with an overview of A/D conversion, emphasizing sigma-delta modulators. It includes a detailed analysis of noise in sigma-delta modulators, analyzes power dissipation in integrator circuits, and addresses practical issues in the circuit design and testing of a high-resolution modulator. The Design of Low-Voltage, Low-Power Sigma-Delta Modulators will be of interest to practicing engineers and researchers in the areas of mixed-signal and analog integrated circuit design.
Author: Libin Yao
Publisher: Springer Science & Business Media
ISBN: 1402041403
Category : Technology & Engineering
Languages : en
Pages : 180
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Book Description
this book is not suitable for the bookstore catalogue
Author: Jose M. de la Rosa
Publisher: John Wiley & Sons
ISBN: 1119275768
Category : Technology & Engineering
Languages : en
Pages : 892
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Book Description
Thoroughly revised and expanded to help readers systematically increase their knowledge and insight about Sigma-Delta Modulators Sigma-Delta Modulators (SDMs) have become one of the best choices for the implementation of analog/digital interfaces of electronic systems integrated in CMOS technologies. Compared to other kinds of Analog-to-Digital Converters (ADCs), Σ∆Ms cover one of the widest conversion regions of the resolution-versus-bandwidth plane, being the most efficient solution to digitize signals in an increasingly number of applications, which span from high-resolution low-bandwidth digital audio, sensor interfaces, and instrumentation, to ultra-low power biomedical systems and medium-resolution broadband wireless communications. Following the spirit of its first edition, Sigma-Delta Converters: Practical Design Guide, 2nd Edition takes a comprehensive look at SDMs, their diverse types of architectures, circuit techniques, analysis synthesis methods, and CAD tools, as well as their practical design considerations. It compiles and updates the current research reported on the topic, and explains the multiple trade-offs involved in the whole design flow of Sigma-Delta Modulators—from specifications to chip implementation and characterization. The book follows a top-down approach in order to provide readers with the necessary understanding about recent advances, trends, and challenges in state-of-the-art Σ∆Ms. It makes more emphasis on two key points, which were not treated so deeply in the first edition: It includes a more detailed explanation of Σ∆Ms implemented using Continuous-Time (CT) circuits, going from system-level synthesis to practical circuit limitations. It provides more practical case studies and applications, as well as a deeper description of the synthesis methodologies and CAD tools employed in the design of Σ∆ converters. Sigma-Delta Converters: Practical Design Guide, 2nd Edition serves as an excellent textbook for undergraduate and graduate students in electrical engineering as well as design engineers working on SD data-converters, who are looking for a uniform and self-contained reference in this hot topic. With this goal in mind, and based on the feedback received from readers, the contents have been revised and structured to make this new edition a unique monograph written in a didactical, pedagogical, and intuitive style.
Author: Gil Cho Ahn
Publisher:
ISBN:
Category : Analog-to-digital converters
Languages : en
Pages : 144
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Book Description
With the ever-increasing demand for portable devices used in applications such as wireless communication, mobile computing, consumer electronics, etc., the scaling of the CMOS process to deep submicron dimensions becomes more important to achieve low-cost, low-power and high-performance digital systems. However, this downscaling also requires similar shrinking of the supply voltage to insure device reliability. Even though the largest amount of signal processing is done in the digital domain, the on-chip analog-to-digital interface circuitry (analog-to-digital and digital-to-analog converters) is an important functional block in the system. These converters are also required to operate with low-voltage supply. In this thesis, design techniques for low-voltage and low-power analog-to-digital converters are proposed. The specific research contributions of this work include (1) introduction of a new low-voltage switching technique for switched- capacitor circuit design, (2) development of low-voltage and low-distortion delta- sigma modulator, (3) development of low-voltage switched-capacitor multiplying digital-to-analog converter (MDAC), (4) a new architecture for the low-power Nyquist rate pipelined ADC design. These design techniques enable the implementation of low-voltage and low-power CMOS analog-to-digital converters. To demonstrate the proposed design techniques, a 0.6 V, 82 dB, 2-2 cascaded audio delta-sigma ADC, a 0.9 V, 10-bit, 20MS/s CMOS pipelined ADC and a 2.4 V, 12-bit, 10MS/s CMOS pipelined ADC were implemented in standard CMOS processes.
Author: Jose M. de la Rosa
Publisher: John Wiley & Sons
ISBN: 1118568435
Category : Technology & Engineering
Languages : en
Pages : 463
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Book Description
A comprehensive overview of Sigma-Delta Analog-to-Digital Converters (ADCs) and a practical guide to their design in nano-scale CMOS for optimal performance. This book presents a systematic and comprehensive compilation of sigma-delta converter operating principles, the new advances in architectures and circuits, design methodologies and practical considerations − going from system-level specifications to silicon integration, packaging and measurements, with emphasis on nanometer CMOS implementation. The book emphasizes practical design issues – from high-level behavioural modelling in MATLAB/SIMULINK, to circuit-level implementation in Cadence Design FrameWork II. As well as being a comprehensive reference to the theory, the book is also unique in that it gives special importance on practical issues, giving a detailed description of the different steps that constitute the whole design flow of sigma-delta ADCs. The book begins with an introductory survey of sigma-delta modulators, their fundamentals architectures and synthesis methods covered in Chapter 1. In Chapter 2, the effect of main circuit error mechanisms is analysed, providing the necessary understanding of the main practical issues affecting the performance of sigma-delta modulators. The knowledge derived from the first two chapters is presented in the book as an essential part of the systematic top-down/bottom-up synthesis methodology of sigma-delta modulators described in Chapter 3, where a time-domain behavioural simulator named SIMSIDES is described and applied to the high-level design and verification of sigma-delta ADCs. Chapter 4 moves farther down from system-level to the circuit and physical level, providing a number of design recommendations and practical recipes to complete the design flow of sigma-delta modulators. To conclude the book, Chapter 5 gives an overview of the state-of-the-art sigma-delta ADCs, which are exhaustively analysed in order to extract practical design guidelines and to identify the incoming trends, design challenges as well as practical solutions proposed by cutting-edge designs. Offers a complete survey of sigma-delta modulator architectures from fundamentals to state-of-the art topologies, considering both switched-capacitor and continuous-time circuit implementations Gives a systematic analysis and practical design guide of sigma-delta modulators, from a top-down/bottom-up perspective, including mathematical models and analytical procedures, behavioural modeling in MATLAB/SIMULINK, macromodeling, and circuit-level implementation in Cadence Design FrameWork II, chip prototyping, and experimental characterization. Systematic compilation of cutting-edge sigma-delta modulators Complete description of SIMSIDES, a time-domain behavioural simulator implemented in MATLAB/SIMULINK Plenty of examples, case studies, and simulation test benches, covering the different stages of the design flow of sigma-delta modulators A number of electronic resources, including SIMSIDES, the statistical data used in the state-of-the-art survey, as well as many design examples and test benches are hosted on a companion website Essential reading for Researchers and electronics engineering practitioners interested in the design of high-performance data converters integrated in nanometer CMOS technologies; mixed-signal designers.
Author: Nianxiong Tan
Publisher: Springer Science & Business Media
ISBN: 1461562074
Category : Technology & Engineering
Languages : en
Pages : 238
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Book Description
Switched-Current Design and Implementation of Oversampling A/D Converters discusses the switched-current (SI) technique and its application in oversampling A/D converters design. The SI technique is an analog sampled-data technique that fully exploits the digital CMOS process. Compared with the traditional switched-capacitor (SC) technique, the SI technique has both pros and cons that are highlighted in the book. With the consideration of similarity and difference of SI and SC techniques, oversampling A/D converter architectures are tailored and optimized for SI design and implementation in the book. Switched-Current Design and Implementation of Oversampling A/D Converters emphasizes the practical aspects of SI circuits without tedious mathematical derivations, and is full of circuit design and implementation examples. There are more than 10 different chips included in the book, demonstrating the high-speed (over 100 MHz) and ultra-low-voltage (1.2 V) operation of SI circuits and systems in standard digital CMOS processes. Therefore, the book is of special value as a practical guide for designing SI circuits and SI oversampling A/D converters. Switched-Current Design and Implementation of Oversampling A/D Converters serves as an excellent reference for analog designers, especially A/D converter designers, and is of interest to digital designers for real-time signal processing who need A/D interfaces. The book may also be used as a text for advanced courses on the subject.
Author: Amir Zjajo
Publisher: Springer Science & Business Media
ISBN: 9048197252
Category : Technology & Engineering
Languages : en
Pages : 311
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Book Description
With the fast advancement of CMOS fabrication technology, more and more signal-processing functions are implemented in the digital domain for a lower cost, lower power consumption, higher yield, and higher re-configurability. This has recently generated a great demand for low-power, low-voltage A/D converters that can be realized in a mainstream deep-submicron CMOS technology. However, the discrepancies between lithography wavelengths and circuit feature sizes are increasing. Lower power supply voltages significantly reduce noise margins and increase variations in process, device and design parameters. Consequently, it is steadily more difficult to control the fabrication process precisely enough to maintain uniformity. The inherent randomness of materials used in fabrication at nanoscopic scales means that performance will be increasingly variable, not only from die-to-die but also within each individual die. Parametric variability will be compounded by degradation in nanoscale integrated circuits resulting in instability of parameters over time, eventually leading to the development of faults. Process variation cannot be solved by improving manufacturing tolerances; variability must be reduced by new device technology or managed by design in order for scaling to continue. Similarly, within-die performance variation also imposes new challenges for test methods. In an attempt to address these issues, Low-Power High-Resolution Analog-to-Digital Converters specifically focus on: i) improving the power efficiency for the high-speed, and low spurious spectral A/D conversion performance by exploring the potential of low-voltage analog design and calibration techniques, respectively, and ii) development of circuit techniques and algorithms to enhance testing and debugging potential to detect errors dynamically, to isolate and confine faults, and to recover errors continuously. The feasibility of the described methods has been verified by measurements from the silicon prototypes fabricated in standard 180nm, 90nm and 65nm CMOS technology.
Author: Ovidiu Bajdechi
Publisher: Springer Science & Business Media
ISBN: 9781402079450
Category : Computers
Languages : en
Pages : 216
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Book Description
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.
