Design of Low-Voltage Bipolar Operational Amplifiers discusses the sub-circuits necessary to build a low-voltage operational amplifier. These include rail-to-rail input stages, rail-to-rail output stages, intermediate stages, protection circuitry and frequency compensation techniques. Of each of these, various implementations are examined. Furthermore, the book discusses realizations in silicon of the amplifiers. The design and implementation of low-voltage bipolar Operational Amplifiers (OpAmps) is fully presented. A low supply voltage is necessary because the tendency towards chip components of smaller dimensions lowers the breakdown voltage of these components. Further, a low supply voltage is favorable because it enables operation of the OpAmp from just one single battery cell. The bipolar technology is chosen, because it is more suited for operation at low-voltages than the MOS technology. The common-mode input voltage of the OpAmp must be able to have any value that fits within the supply voltage range. Input stages are discussed which are able to realize this at supply voltages down to 1.8 V, as well as down to 1 V. The output voltage of the OpAmp must be able to have any value within the supply voltage range. One of the 1 V output stages that is discussed, the multi-path driven output stage, also has a high bandwidth with a high gain. In addition to the input and output stage, the OpAmp comprises an intermediate stage, between the input stage and the output stage, to boost the overall gain of the OpAmp, and a class AB current control. A frequency compensation technique is used to split apart the pole frequencies in the transfer function. A disadvantage of this nested Miller compensation, is that the resulting bandwidth is reduced by a factor of two. A new method, multi-path-driven Miller compensation, which does not have this drawback, is therefore introduced. Several realizations are evaluated and a figure of merit is defined for the performance comparison of the OpAmps. One of the OpAmps operates at a 1 V supply, has a 3.4 MHz bandwidth with a 100 pF load and has a 700 &mgr;A supply current. The book is an excellent reference for professional designers of amplifiers and may be used as a text for advanced courses on the subject.

The operational amplifier ("op amp") is the most versatile and widely used type of analog IC, used in audio and voltage amplifiers, signal conditioners, signal converters, oscillators, and analog computing systems. Almost every electronic device uses at least one op amp. This book is Texas Instruments' complete professional-level tutorial and reference to operational amplifier theory and applications. Among the topics covered are basic op amp physics (including reviews of current and voltage division, Thevenin's theorem, and transistor models), idealized op amp operation and configuration, feedback theory and methods, single and dual supply operation, understanding op amp parameters, minimizing noise in op amp circuits, and practical applications such as instrumentation amplifiers, signal conditioning, oscillators, active filters, load and level conversions, and analog computing. There is also extensive coverage of circuit construction techniques, including circuit board design, grounding, input and output isolation, using decoupling capacitors, and frequency characteristics of passive components. The material in this book is applicable to all op amp ICs from all manufacturers, not just TI. Unlike textbook treatments of op amp theory that tend to focus on idealized op amp models and configuration, this title uses idealized models only when necessary to explain op amp theory. The bulk of this book is on real-world op amps and their applications; considerations such as thermal effects, circuit noise, circuit buffering, selection of appropriate op amps for a given application, and unexpected effects in passive components are all discussed in detail. *Published in conjunction with Texas Instruments *A single volume, professional-level guide to op amp theory and applications *Covers circuit board layout techniques for manufacturing op amp circuits.

This volume of Analog Circuit Design concentrates on three topics: Operational Amplifiers. A-to-D converters and Analog CAD. The book comprises six papers on each topic written by internationally recognised experts. These papers have a tutorial nature aimed at improving the design of analog circuits. The book is divided into three parts. Part I, Operational Amplifiers, presents new technologies for the design of Op-Amps in both bipolar and CMOS technologies. Two papers demonstrate techniques for improving frequency and gain behavior at high voltage. Low voltage bipolar Op-Amp design is treated in another paper. The realization high-speed and high gain VLSI building blocks in CMOS is demonstrated in two papers. The final paper shows how to provide output power with CMOS buffer amplifiers. Part II, Analog-to-Digital Conversion, presents papers which address very high conversion speeds and very high resolution implementations using sigma-delta modulation architectures. Analog to Digital converters provide the link between the analog world of transducers and the digital world of signal processing and computing. High-performance bipolar and MOS technologies result in high-resolution or high-speed convertors which can be applied in digital audio or video systems. Furthermore, the advanced high-speed bipolar technologies show an increase in conversion speed into the gigahertz range. Part III, Analog Computer Aided Design, presents the latest research towards providing analog circuit designers with the tools needed to automate much of the design process. The techniques and methodologies described demonstrate the advances being made in developing analog design tools comparable with those already available for digital design. The papers in this volume are based on those presented at the Workshop on Advances in Analog Circuit Design held in Delft, The Netherlands in 1992. The main intention of the workshop was to brainstorm with a group of about 100 analog design experts on the new possibilities and future developments on the above topics. The result of this brainstorming is contained in Analog Circuit Design, which is thus an important reference for researchers and design engineers working in the forefront of analog circuit design and research.

Compact Low-Voltage and High-Speed CMOS, BiCMOS and Bipolar Operational Amplifiers discusses the design of integrated operational amplifiers that approach the limits of low supply voltage or very high bandwidth. The resulting realizations span the whole field of applications from micro-power CMOS VLSI amplifiers to 1-GHz bipolar amplifiers. The book presents efficient circuit topologies in order to combine high performance with simple solutions. In total twelve amplifier realizations are discussed. Two bipolar amplifiers are discussed, a 1-GHz operational amplifier and an amplifier with a high ratio between the maximum output current and the quiescent current. Five amplifiers have been designed in CMOS technology, extremely compact circuits that can operate on supply voltages down to one gate-source voltage and two saturation voltages which equals about 1.4 V and, ultimate-low-voltage amplifiers that can operate on supply voltages down to one gate-source voltage and one saturation voltage which amounts to about 1.2 V. In BiCMOS technology five amplifiers have been designed. The first two amplifiers are based on a compact topology. Two other amplifiers are designed to operate on low supply voltages down to 1.3 V. The final amplifier has a unity-gain frequency of 200 MHz and can operate down to 2.5 V. Compact Low-Voltage and High-Speed CMOS, BiCMOS and Bipolar Operational Amplifiers is intended for the professional analog designer. Also, it is suitable as a text book for advanced courses in amplifier design.

Small Signal Audio Design is a highly practical handbook providing an extensive repertoire of circuits that can be assembled to make almost any type of audio system. The publication of Electronics for Vinyl has freed up space for new material, (though this book still contains a lot on moving-magnet and moving-coil electronics) and this fully revised third edition offers wholly new chapters on tape machines, guitar electronics, and variable-gain amplifiers, plus much more. A major theme is the use of inexpensive and readily available parts to obtain state-of-the-art performance for noise, distortion, crosstalk, frequency response accuracy and other parameters. Virtually every page reveals nuggets of specialized knowledge not found anywhere else. For example, you can improve the offness of a fader simply by adding a resistor in the right place- if you know the right place. Essential points of theory that bear on practical audio performance are lucidly and thoroughly explained, with the mathematics kept to an absolute minimum. Self’s background in design for manufacture ensures he keeps a wary eye on the cost of things. This book features the engaging prose style familiar to readers of his other books. You will learn why mercury-filled cables are not a good idea, the pitfalls of plating gold on copper, and what quotes from Star Trek have to do with PCB design. Learn how to: make amplifiers with apparently impossibly low noise design discrete circuitry that can handle enormous signals with vanishingly low distortion use humble low-gain transistors to make an amplifier with an input impedance of more than 50 megohms transform the performance of low-cost-opamps build active filters with very low noise and distortion make incredibly accurate volume controls make a huge variety of audio equalisers make magnetic cartridge preamplifiers that have noise so low it is limited by basic physics, by using load synthesis sum, switch, clip, compress, and route audio signals be confident that phase perception is not an issue This expanded and updated third edition contains extensive new material on optimising RIAA equalisation, electronics for ribbon microphones, summation of noise sources, defining system frequency response, loudness controls, and much more. Including all the crucial theory, but with minimal mathematics, Small Signal Audio Design is the must-have companion for anyone studying, researching, or working in audio engineering and audio electronics.

Oversampling techniques based on sigma-delta modulation are widely used to implement the analog/digital interfaces in CMOS VLSI technologies. This approach is relatively insensitive to imperfections in the manufacturing process and offers numerous advantages for the realization of high-resolution analog-to-digital (A/D) converters in the low-voltage environment that is increasingly demanded by advanced VLSI technologies and by portable electronic systems. In The Design of Low-Voltage, Low-Power Sigma-Delta Modulators, an analysis of power dissipation in sigma-delta modulators is presented, and a low-voltage implementation of a digital-audio performance A/D converter based on the results of this analysis is described. Although significant power savings can typically be achieved in digital circuits by reducing the power supply voltage, the power dissipation in analog circuits actually tends to increase with decreasing supply voltages. Oversampling architectures are a potentially power-efficient means of implementing high-resolution A/D converters because they reduce the number and complexity of the analog circuits in comparison with Nyquist-rate converters. In fact, it is shown that the power dissipation of a sigma-delta modulator can approach that of a single integrator with the resolution and bandwidth required for a given application. In this research the influence of various parameters on the power dissipation of the modulator has been evaluated and strategies for the design of a power-efficient implementation have been identified. The Design of Low-Voltage, Low-Power Sigma-Delta Modulators begins with an overview of A/D conversion, emphasizing sigma-delta modulators. It includes a detailed analysis of noise in sigma-delta modulators, analyzes power dissipation in integrator circuits, and addresses practical issues in the circuit design and testing of a high-resolution modulator. The Design of Low-Voltage, Low-Power Sigma-Delta Modulators will be of interest to practicing engineers and researchers in the areas of mixed-signal and analog integrated circuit design.