Download or read book Image Sensors Employing Oversampling Sigma delta Analog to digital Conversion with High Dynamic Range and Low Power written by Danijel Maričić and published by . This book was released on 2011 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A wide variety of image sensors have been developed for numerous applications ranging from consumer imaging and cell phones to space imaging, but in virtually every domain there is an ever present need for improved image quality and reduced power consumption. Most CMOS image sensors now include on-chip analog to digital (A/D) conversion to enable easier integration into a variety of camera platforms. Nearly all of these employ Nyquist rate A/D converters, ranging from designs that share one A/D converter for the entire imaging array to designs that effectively have a separate ADC for each pixel. In this work we explore the alternative of employing an oversampling sigma-delta A/D converter at each pixel. Technology scaling leads to lower supply voltages, which in turn affects the dynamic range and the signal-to-noise (SNR) ratio of the image sensor. We show that sigma-delta A/D conversion enables further supply voltage reduction without decreasing the sensor's sensitivity and the SNR. We also demonstrate a sigma-delta image sensor implementation with reduced analog circuit complexity in comparison to earlier efforts. Furthermore, the sigma-delta modulator is insensitive to the inevitable electronic noise at the input of the comparator, which leads to improved light sensitivity. In this work we explore a specific implementation of the sigma-delta image sensor that may be capable of reaching the theoretical limit of detecting a single photon-generated electron during the exposure time."--Leaf v.

Download or read book High Performance Silicon Imaging written by Daniel Durini and published by Woodhead Publishing. This book was released on 2019-10-19 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: High Performance Silicon Imaging: Fundamentals and Applications of CMOS and CCD Sensors, Second Edition, covers the fundamentals of silicon image sensors, addressing existing performance issues and current and emerging solutions. Silicon imaging is a fast growing area of the semiconductor industry. Its use in cell phone cameras is already well established, with emerging applications including web, security, automotive and digital cinema cameras. The book has been revised to reflect the latest state-of-the art developments in the field, including 3D imaging, advances in achieving lower signal noise, and new applications for consumer markets. The fundamentals section has also been expanded to include a chapter on the characterization and testing of CMOS and CCD sensors that is crucial to the success of new applications. This book is an excellent resource for both academics and engineers working in the optics, photonics, semiconductor and electronics industries. Covers the fundamentals of silicon-based image sensors and technical advances, focusing on performance issues Looks at image sensors in applications, such as mobile phones, scientific imaging, and TV broadcasting, and in automotive, consumer and biomedical applications Addresses the theory behind 3D imaging and 3D sensor development, including challenges and opportunities

Download or read book Proceedings of 3rd 2023 International Conference on Autonomous Unmanned Systems 3rd ICAUS 2023 written by Yi Qu and published by Springer Nature. This book was released on with total page 501 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oversampling Delta Sigma Data Converters written by James C. Candy and published by Wiley-IEEE Press. This book was released on 1992 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: This now famous anthology brings together various aspects of oversampling methods and compares and evaluates design approaches. It describes the theoretical analysis of converter performances, the actual design of converters and their simulation, circuit implementations, and applications.

Download or read book Switched Current Design and Implementation of Oversampling A D Converters written by Nianxiong Tan and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Systematic Design of Sigma Delta Analog to Digital Converters written by Ovidiu Bajdechi and published by Springer Science & Business Media. This book was released on 2004-04-30 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Low voltage Low power High resolution Broadband Oversampling Analog to digital Conversion written by Je-Kwang Cho and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Oversampling A/D converters exchange resolution in time for that in amplitude by oversampling the input signal and employing sigma-delta modulators that suppress quantization error within the signal bandwidth. As a result, a high-precision A/D converter output can be generated by using back-end digital decimation filtering. However, the use of oversampling converters is typically limited to low bandwidth applications, such as digital audio systems. Recently, sigma-delta modulators operating at relatively low oversampling ratios have been shown to be effective at achieving high-performance A/D conversion for signal bandwidths of several megahertz. However, the limited signal swings and voltage headroom that accompany the aggressive scaling of CMOS technology result in high power dissipation of the analog circuits in conventional modulator architectures. Although sigma-delta modulators based on input feedforward architectures enable reduced analog power dissipation, they require a high-speed quantizer and feedback DAC with attendant high power dissipation. The objective of this research is to investigate means of power minimization for both analog and digital circuits in sigma-delta modulators operating from low supply voltages over several mega-hertz of signal bandwidth while maintaining high precision. To relax the timing constraints on the quantizer and feedback DAC, a half-sample delayed-input feedback architecture is employed in the implementation of a second-order sigma-delta modulator. Power dissipation in the analog amplifiers of the feedforward architecture is reduced by using a single amplifier to implement the two integrators. This amplifier sharing also reduces the area occupied by the integrators. The power scaling of amplifiers in discrete-time multi-order amplifier-based analog integrators is exploited by dynamically biasing the shared amplifier. A low-power, high-speed charge pump circuit for dynamic biasing minimizes the power overhead. Finally, a multi-bit quantizer, which effectively reduces the output amplitude and power dissipation of the integrators, employs interpolated preamplifiers to conserve power and area in the preamplifiers. A 2-2 cascaded sigma-delta modulator, operating from a 1.0-V supply, has been designed using a half-sample delayed-input feedforward architecture for each stage, dynamically-biased amplifier sharing for realization of the integrators, and interpolated multi-bit quantization. An experimental prototype of the proposed modulator has been integrated in a 0.18-[micrometer] CMOS technology. At a 40-MHz sampling rate, the prototype achieves 92 dB of dynamic range, a 91-dB peak SNR and an 84-dB peak SNDR for a signal bandwidth of 1.25 MHz, while consuming only 24.3 mW of total power from a 1.0-V supply.

Download or read book Low Power Low Voltage Sigma Delta Modulators in Nanometer CMOS written by Libin Yao and published by Springer Science & Business Media. This book was released on 2006-07-09 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: this book is not suitable for the bookstore catalogue

Download or read book Science Abstracts written by and published by . This book was released on 1993 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Continuous Time Sigma Delta A D Conversion written by Friedel Gerfers and published by Springer Science & Business Media. This book was released on 2006-02-27 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sigma-delta A/D converters are a key building block in wireless and multimedia applications. This comprehensive book deals with all relevant aspects arising during the analysis, design and simulation of the now widespread continuous-time implementations of sigma-delta modulators. The results of several years of research by the authors in the field of CT sigma-delta modulators are covered, including the analysis and modeling of different CT modulator architectures, CT/DT loop filter synthesis, a detailed error analysis of all components, and possible compensation/correction schemes for the non-ideal behavior in CT sigma-delta modulators. Guidance for obtaining low-power consumption and several practical implementations are also presented. It is shown that all the proposed new theories, architectures and possible correction techniques have been confirmed by measurements on discrete or integrated circuits. Quantitative results are also provided, thus enabling prediction of the resulting accuracy.

Download or read book Binary Dithered Oversampling Analog to Digital Converter written by Jirar Nicolas Helou and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: It is common knowledge among engineers that the best way to process analog signals would be in the digital domain. Signal processing varies from simple arithmetic operations such as adding multiple signals together to more complex operations such as implementing high order filters. Compared to analog, the digital domain presents a faster, more robust and more dynamic approach to handle signal processing. In order to perform digital processing on analog signals, these signals need to be properly converted into the digital domain with the best resolution as well as preserving the content of the signal with the least information loss. Sigma Delta converters are the industry standards for high-resolution analog to digital converters (ADCs). To achieve this high resolution, the design requires high order integrators, multi-bit converters and complex digital filters. This results in a large size and power inefficient integrated circuit. This dissertation presents a novel analog to digital converter architecture that competes in terms of power, size and resolution with sigma delta converters. The theory behind this new architecture is deduced from half-toning in image processing. It captures the theory of error diffusion and blue noise masking used on multi-tone image processing and applies it in a similar fashion to digitize continuous analog signals. Simulations have shown similar results for images half-toned through error diffusion and blue noise masking [17]. Moreover, there is a direct connection between error diffusion and sigma delta modulation, which inspired us to pursue the idea of developing a new ADC, the binary dithered oversampling ADC (BDO), based on blue noise dithering. We started with system level simulations to compare the performance of sigma delta to BDO and then developed proof of concept experiments to build the proper circuitry. It is important to mention that there has been a lot of work published about building simulation models to generate blue noise dither but there have not been a circuit developed to solely generate analog blue noise dither. It is true that a sigma delta modulator generates blue noise dither, but this is due to its negative feedback, which in return limits its speed. In this dissertation we are proposing a simple circuit, no negative feedback or integrators, that operates at much lower power and capable of achieving a bit resolution that is comparable to a first order sigma delta modulator. Two generations of the BDO converter were implemented using 0.5 mu-m -CMOS technology to demonstrate their functionality. We also implemented a first order continuous time sigma delta modulator on the same integrated chip to compare both architectures. We compared both converters in terms of size, power, resolution and robustness. The proposed binary dithered oversampled converter was significantly smaller in size, consumed less power and achieved comparable resolution to that of the first order sigma delta modulator. In terms of robustness, sigma delta modulator can achieve higher resolution if we increase the oversampling ratio and use higher order integrators. The tradeoff here is an increase in size and power consumption in addition to facing some stability issues due to the high order integrators. On the other hand, the BDO converter can increase its resolution by optimizing some of its components, such as enhancing the high-pass filter responsible for the blue noise shaping, without radically increasing its size or power consumption.

Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 1904 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Prototype of a New Class of Oversampling ADC written by Jun He and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Analog-to-digital (A/D) and digital-to-analog (D/A) converters are important blocks in signal processing system because they provide the link between the analog world and digital systems. Compared with Nyquist-rate data converters, oversampling data converters are more desirable for modern submicron technologies with low voltage supplies. Today, all existing oversampling modulators in popular use are derived from sigma-delta modulation. Stability is the most significant problem in the sigma-delta modulator, because the ultimate accuracy is limited by stability. As the aggressiveness of the design increases, the margin of stability diminishes rapidly. This thesis presents the design and experimental results of the first prototype circuit implementation of the novel oversampling modulation scheme proposed by Dr. Takis Zourntos. This new class of oversampling modulators are theoretically stable. With less stability limitation, the new class of modulators can potentially achieve higher signal-to-noise ratio (SNR) or less power by designing the modulator more aggressively. This thesis describes the methods and procedures of how the new oversampling modulation theory is implemented into a circuit. Some novel circuit architectures are proposed in this modulator, such as a filter which can provide status outputs for the controller and realize arbitrary zeros and poles, comparators with synchronization latches to eliminate the effect of metastability, and a digital-to-analog converter (DAC) with current calibration circuits for high linearity. A third-order continuous-time oversampling modulator employing 4-bit quantization is implemented in a 0.35-[mu]m double-poly complementary metal oxide semiconductor (CMOS) technology, with a chip area of 2150 x 2150 [mu]m2. Simulation results show it achieves 83.7-dB peak SQNR, 90-dB dynamic range over a 500kHz input signal bandwidth, and 60 mW power consumption.

Download or read book Design Techniques for Wideband Low power Delta Sigma Analog to digital Converters written by Yan Wang and published by . This book was released on 2010 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Delta-Sigma analog-to-digital converters (ADCs) are traditionally used in high quality audio systems, instrumentation and measurement (I&M) and biomedical devices. With the continued downscaling of CMOS technology, they are becoming popular in wideband applications such as wireless and wired communication systems,high-definition television and radar systems. There are two general realizations of a [Delta-Sigma] modulator. One is based on the discrete-time (DT) switched-capacitor (SC) circuitry and the other employs continuous-time (CT) circuitry. Compared to a CT structure, the DT [Delta-Sigma] ADC is easier to analyze and design, is more robust to process variations and jitter noise, and is more flexible in the multi-mode applications. On the other hand, the CT [Delta-Sigma] ADC does not suffer from the strict settling accuracy requirement for the loop filter and thus can achieve lower power dissipation and higher sampling frequency than its DT counterpart. In this thesis, both DT and CT [Delta-Sigma] ADCs are investigated. Several design innovations, in both system-level and circuit-level, are proposed to achieve lower power consumption and wider signal bandwidth. For DT [Delta-Sigma] ADCs, a new dynamic-biasing scheme is proposed to reduce opamp bias current and the associated signal-dependent harmonic distortion is minimized by using the low-distortion architecture. The technique was verified in a 2.5MHz BW and 13bit dynamic range DT [Delta-Sigma] ADC. In addition, a second-order noise coupling technique is presented to save two integrators for the loop filter, and to achieve low power dissipation. Also, a direct-charge-transfer (DCT) technique is suggested to reduce the speed requirements of the adder, which is also preferable in wideband low-power applications. For CT [Delta-Sigma] ADCs, a wideband low power CT 2-2 MASH has been designed. High linearity performance was achieved by using a modified low-distortion technique, and the modulator achieves higher noise-shaping ability than the single stage structure due to the inter-stage gain. Also, the quantization noise leakage due to analog circuit non-idealities can be adaptively compensated by a designed digital calibration filter. Using a 90nm process, simulation of the modulator predicts a 12bit resolution within 20MHz BW and consumes only 25mW for analog circuitry. In addition, the noise-coupling technique is investigated and proposed for the design of CT [Delta-Sigma] ADCs and it is promising to achieve low power dissipation for wideband applications. Finally, the application of noise-coupling technique is extended and introduced to high-accuracy incremental data converters. Low power dissipation can be expected.

Download or read book Proceedings written by and published by . This book was released on 2004 with total page 1306 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Infrared Readout Electronics written by and published by . This book was released on 1998 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book CMOS Sigma Delta Converters written by José M. de la Rosa and published by Wiley-IEEE Press. This book was released on 2013-05-06 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.