Noise Speed And Power Tradeoffs In Pipelined Analog To Digital Converters

Analog-to-digital converters (ADCs) are widely used in communication systems to interface analog and digital circuits. While the speed, power, and area of digital circuits directly benefit from the decreasing channel length of CMOS devices, analog circuits suffer from reduced headroom, lower intrinsic gain, and higher device mismatch. Consequently, it has been increasingly difficult to design high-speed and low-power pipelined ADCs using conventional op amps. This work presents a pipelined ADC that employs novel "charge-steering" op amps to relax the trade-offs among speed, noise, and power consumption. Such op amps afford a fourfold increase in speed and a twofold reduction in noise for a given power consumption and voltage gain. Using a new clock gating technique, the ADC digitally calibrates the nonlinearity and gain error at full speed. A prototype realized in 65-nm CMOS technology achieves a resolution of 10 bits with a sampling rate of 800 MHz, a power consumption of 19 mW, an SNDR of 52.2 dB at Nyquist, and an FoM of 53 fJ/conversion-step. A new background calibration technique is also proposed to accommodate temperature and supply variations.

Pipelined ADCs have seen phenomenal improvements in performance over the last few years. As such, when designing a pipelined ADC a clear understanding of the design tradeoffs, and state of the art techniques is required to implement today's high performance low power ADCs.

The Analog to Digital Converters represent one half of the link between the world we live in - analog - and the digital world of computers, which can handle the computations required in digital signal processing. These devices are mathematically very complex due to their nonlinear behavior and thus fairly difficult to analyze without the use of simulation tools. High Speed A/D Converters: Understanding Data Converters Through SPICE presents the subject from the practising engineer's point of view rather than from the academic's point of view. A practical approach is emphasized. High Speed A/D Converters: Understanding Data Converters Through SPICE is intended as a learning tool by providing building blocks that can be stacked on top of each other to build higher order systems. The book provides a guide to understanding the various topologies used in A/D converters by suggesting simple methods for the blocks used in an A/D converter. The converters discussed throughout the book constitute a class of devices called undersampled or Nyquist converters. The tools used in deriving the results presented are: TopSpice® by Penzar - a mixed mode SPICE simulator - version 5.90. The files included in Appendix A were written for this tool. However, most circuit files need only minor adjustments to be used on other SPICE simulators such as PSpice, Hspice, IS_Spice and Micro-Cap IV; Mathcad 2000 - Professional by Mathsoft. This tool is very useful in performing FFT analysis as well as drawing some of the graphs. Again, the mathcad files are included to help the user analyze the data. High Speed A/D Converters: Understanding Data Converters Through SPICE not only supplies the models for the A/D converters for SPICE program but also describes the physical reasons for the converter's performance.

Digitally Assisted Pipeline ADCs: Theory and Implementation explores the opportunity to reduce ADC power dissipation by leveraging digital signal processing capabilities in fine line integrated circuit technology. The described digitally assisted pipelined ADC uses a statistics-based system identification technique as an enabling element to replace precision residue amplifiers with simple open-loop gain stages. The digital compensation of analog circuit distortion eliminates one key factor in the classical noise-speed-linearity constraint loop and thereby enables a significant power reduction. Digitally Assisted Pipeline ADCs: Theory and Implementation describes in detail the implementation and measurement results of a 12-bit, 75-MSample/sec proof-of-concept prototype. The Experimental converter achieves power savings greater than 60% over conventional implementations. Digitally Assisted Pipeline ADCs: Theory and Implementation will be of interest to researchers and professionals interested in advances of state-of-the-art in A/D conversion techniques.

Offset Reduction Techniques in High-Speed Analog-to-Digital Converters analyzes, describes the design, and presents test results of Analog-to-Digital Converters (ADCs) employing the three main high-speed architectures: flash, two-step flash and folding and interpolation. The advantages and limitations of each one are reviewed, and the techniques employed to improve their performance are discussed.

Need to get up to speed quickly on the latest advances in high performance data converters? Want help choosing the best architecture for your application? With everything you need to know about the key new converter architectures, this guide is for you. It presents basic principles, circuit and system design techniques and associated trade-offs, doing away with lengthy mathematical proofs and providing intuitive descriptions upfront. Everything from time-to-digital converters to comparator-based/zero-crossing ADCs is covered and each topic is introduced with a short summary of the essential basics. Practical examples describing actual chips, along with extensive comparison between architectural or circuit options, ease architecture selection and help you cut design time and engineering risk. Trade-offs, advantages and disadvantages of each option are put into perspective with a discussion of future trends, showing where this field is heading, what is driving it and what the most important unanswered questions are.

This book helps engineers to grasp fundamental theories and design principles by presenting physical and intuitive explanations of switched-capacitor circuits. Numerous circuit examples are discussed and the author emphasizes the most important and fundamental principles involved in implementing state-of-the-art switched-capacitor circuits for analog signal processing and power management applications. Throughout the book, the author presents numerous step-by-step tutorials and gives practical design examples.While some quantitative analysis is necessary to understand underlying concepts, tedious mathematical equations and formal proofs are avoided. An intuitive appreciation for switched-capacitor circuits is achieved.Much of the existing information on contemporary switched-capacitor circuit applications is in the form of applications notes and data sheets for various switched-capacitor ICs. This book compiles such information in a single volume and coherently organizes and structures it.The author has his own website at www.mingliangliu.com * Step-by-step tutorials which emphasize the most fundamental principals of switched-capacitor circuits * Few tedious mathematical equations * The first easy-to-understand compilation on this subject--most information available is not very cohesive