High Speed A/D Converters

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 behaviour and thus fairly difficult to analyze without the use of simulation tools. This book presents the subject from the practising engineer's point of view rather than that of the academic, therefore a practical approach is emphasized. It 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: TopSpiceTM by Penzar, a mixed mode SPICE simulator, version 5.90. 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.Also used was Mathcad 2000 - Professional by Mathsoft. This tool is useful in performing FFT analysis as well as drawing graphs. Again, the mathcad files are included to help the user analyze the data. This book not only supplies the models for the A/D converters for SPICE program, but also describes the physical reasons for the converter's performance.