A transistorized logarithmic analog-to-digital converter of d-c voltage into pulses is described. The input voltage (3 mv - 3 v) is first converted into voltage pulses by a sampling gate circuit. These voltage pulses excite an LC circuit whose oscillations are tuned to resonate with the gate control pulses. The output of the LC circuit is amplified, limited, and fed to an amplitude discriminator, whose output is a packet of pulses. The number of pulses in the packet is proportional to the logarithm of the input d-c voltage.
This book presents a novel logarithmic conversion architecture based on cross-coupled inverter. An overview of the current state of the art of logarithmic converters is given where most conventional logarithmic analog-to-digital converter architectures are derived or adapted from linear analog-to-digital converter architectures, implying the use of analog building blocks such as amplifiers. The conversion architecture proposed in this book differs from the conventional logarithmic architectures. Future possible studies on integrating calibration in the voltage to time conversion element and work on an improved conversion architecture derived from the architecture are also presented in this book.
A practical, engineering book discussing the most modern and general techniques for designing analog integrated circuits which are not digital (excluding computer circuits). Covers the basics of the devices, manufacturing technology, design procedures, shortcuts, and analytic techniques. Includes examples and illustrations of the best current practice.
As the frequency of communication systems increases and the dimensions of transistors are reduced, more and more stringent performance requirements are placed on analog circuits. This is a trend that is bound to continue for the foreseeable future and while it does, understanding performance trade-offs will constitute a vital part of the analog design process. It is the insight and intuition obtained from a fundamental understanding of performance conflicts and trade-offs, that ultimately provides the designer with the basic tools necessary for effective and creative analog design. Trade-offs in Analog Circuit Design, which is devoted to the understanding of trade-offs in analog design, is quite unique in that it draws together fundamental material from, and identifies interrelationships within, a number of key analog circuits. The book covers ten subject areas: Design methodology, Technology, General Performance, Filters, Switched Circuits, Oscillators, Data Converters, Transceivers, Neural Processing, and Analog CAD. Within these subject areas it deals with a wide diversity of trade-offs ranging from frequency-dynamic range and power, gain-bandwidth, speed-dynamic range and phase noise, to tradeoffs in design for manufacture and IC layout. The book has by far transcended its original scope and has become both a designer's companion as well as a graduate textbook. An important feature of this book is that it promotes an intuitive approach to understanding analog circuits by explaining fundamental relationships and, in many cases, providing practical illustrative examples to demonstrate the inherent basic interrelationships and trade-offs. Trade-offs in Analog Circuit Design draws together 34 contributions from some of the world's most eminent analog circuits-and-systems designers to provide, for the first time, a comprehensive text devoted to a very important and timely approach to analog circuit design.
Low-Voltage CMOS Log Companding Analog Design presents in detail state-of-the-art analog circuit techniques for the very low-voltage and low-power design of systems-on-chip in CMOS technologies. The proposed strategy is mainly based on two bases: the Instantaneous Log Companding Theory, and the MOSFET operating in the subthreshold region. The former allows inner compression of the voltage dynamic-range for very low-voltage operation, while the latter is compatible with CMOS technologies and suitable for low-power circuits. The required background on the specific modeling of the MOS transistor for Companding is supplied at the beginning. Following this general approach, a complete set of CMOS basic building blocks is proposed and analyzed for a wide variety of analog signal processing. In particular, the covered areas include: amplification and AGC, arbitrary filtering, PTAT generation, and pulse duration modulation (PDM). For each topic, several case studies are considered to illustrate the design methodology. Also, integrated examples in 1.2um and 0.35um CMOS technologies are reported to verify the good agreement between design equations and experimental data. The resulting analog circuit topologies exhibit very low-voltage (i.e. 1V) and low-power (few tenths of uA) capabilities. Apart from these specific design examples, a real industrial application in the field of hearing aids is also presented as the main demonstrator of all the proposed basic building blocks. This system-on-chip exhibits true 1V operation, high flexibility through digital programmability and very low-power consumption (about 300uA including the Class-D amplifier). As a result, the reported ASIC can meet the specifications of a complete family of common hearing aid models. In conclusion, this book is addressed to both industry ASIC designers who can apply its contents to the synthesis of very low-power systems-on-chip in standard CMOS technologies, as well as to the teachers of modern circuit design in electronic engineering.
