Murmann B. Digitally Assisted Pipeline ADCs 2004 torrent

Textbook in PDF format

The continued reduction of integrated circuit feature sizes and commensurate improvements in device performance are fueling the progress to higher functionality and new application areas. For example, over the last 15 years, the performance of microprocessors has increased 1000 times. Analog circuit performance has also improved, albeit at a slower pace. For example, over the same period the speed/resolution figure-of-merit of analog-to-digital converters improved by only a factor 10. Of the many reasons for this disparity between analog and digital circuit performance advances, accuracy requirements stand out as a critical constraint in most analog circuits while being virtually absent in digital designs. Thermal noise, linearity, and matching are distinctly analog circuit problems and require design tradeoffs that invariably lower achievable performance. For example, linearity requirements are usually met with highgain feedback loops. Unfortunately, this solution also lowers circuit speed and results in elevated noise, reduced signal range, and increased power dissipation. Technology scaling, while unquestionably advantageous for digital circuits, further exacerbates analog circuit design challenges. While offering increased speed, scaled devices suffer from reduced intrinsic gain, further adding to the design challenge of high-gain feedback loops. Reduced supply voltages lower the ratio of useful signal range to supply, leading to increased power dissipation in noise-limited circuits. A large range of solutions to overcome these challenges is available to designers, both at the technology and circuits level. At the process level they include high supply options and a choice of transistor threshold voltages. Circuit innovations consist of gain boosting and nested Miller compensation. While extending the feasibility of analog circuits in scaled technologies with low supply voltages, these techniques come at the cost of a combination of increased process complexity, reduced performance, and added power dissipation.
This book proposes a different approach that takes advantage of the availability of high performance digital processing to relax analog circuit linearity requirements. The use of simple but nonlinear open loop amplification translates into increased analog circuit performance or lower power dissipation. In a careful design that uses a modern process, the area and power penalty of the added digital circuitry is negligible and benefits fully from further technology scaling. Performance demands and design challenges for analog circuits will continue to increase in the future. This book gives the designer a powerful new tool to meet these demands