High Frequency Continuous Time Filters In Digital Cmos Processes

There is an ever increasing trend towards putting entire systems on a single chip. This means that analog circuits will have to coexist on the same substrate along with massive digital systems. Since technologies are optimized with these digital systems in mind, designers will have to make do with standard CMOS processes in the years to come. We address analog filter design from this perspective. Filters form important blocks in applications ranging from computer disc-drive chips to radio transceivers. In this book, we develop the theory and techniques necessary for the implementation of high frequency (hundreds of megahertz) programmable continuous time filters in standard CMOS processes. Since high density poly-poly capacitors are not available in these technologies, alternative capacitor structures have to be found. Met- metal capacitors have low specific capacitance. An alternative is to use the (inherently nonlinear) capacitance formed by MOSFET gates. In Chapter 2, we focus on the use of MOS capacitors as integrating elements. A physics-based model which predicts distortion accurately is presented for a two-terminal MOS structure in accumulation. Distortion in these capacitors as a function of signal swing and bias voltage is computed. Chapter 3 reviews continuous-time filter architectures in the light of bias-dependent integrating capacitors. We also discuss the merits and demerits of various CMOS transconductance elements. The problems encountered in designing high frequency programmable filters are discussed in detail.

This book presents a new filter design approach and concentrates on the circuit techniques that can be utilized when designing continuous-time low-pass filters in modern ultra-deep-submicron CMOS technologies for integrated wideband radio receivers. Coverage includes system-level issues related to the design and implementation of a complete single-chip radio receiver and related to the design and implementation of a filter circuit as a part of a complete single-chip radio receiver. Presents a new filter design approach, emphasizing low-voltage circuit solutions that can be implemented in modern, ultra-deep-submicron CMOS technologies;Includes filter circuit implementations designed as a part of a single-chip radio receiver in modern 1.2V 0.13um and 65nm CMOS;Describes design and implementation of a continuous-time low-pass filter for a multicarrier WCDMA base-station;Emphasizes system-level considerations throughout.

This book brings together contributions from experts in the fields to describe the current status of important topics in solid-state circuit technologies. It consists of 20 chapters which are grouped under the following categories: general information, circuits and devices, materials, and characterization techniques. These chapters have been written by renowned experts in the respective fields making this book valuable to the integrated circuits and materials science communities. It is intended for a diverse readership including electrical engineers and material scientists in the industry and academic institutions. Readers will be able to familiarize themselves with the latest technologies in the various fields.

With the fast advancement of CMOS fabrication technology, more and more signal-processing functions are implemented in the digital domain for a lower cost, lower power consumption, higher yield, and higher re-configurability. This has recently generated a great demand for low-power, low-voltage A/D converters that can be realized in a mainstream deep-submicron CMOS technology. However, the discrepancies between lithography wavelengths and circuit feature sizes are increasing. Lower power supply voltages significantly reduce noise margins and increase variations in process, device and design parameters. Consequently, it is steadily more difficult to control the fabrication process precisely enough to maintain uniformity. The inherent randomness of materials used in fabrication at nanoscopic scales means that performance will be increasingly variable, not only from die-to-die but also within each individual die. Parametric variability will be compounded by degradation in nanoscale integrated circuits resulting in instability of parameters over time, eventually leading to the development of faults. Process variation cannot be solved by improving manufacturing tolerances; variability must be reduced by new device technology or managed by design in order for scaling to continue. Similarly, within-die performance variation also imposes new challenges for test methods. In an attempt to address these issues, Low-Power High-Resolution Analog-to-Digital Converters specifically focus on: i) improving the power efficiency for the high-speed, and low spurious spectral A/D conversion performance by exploring the potential of low-voltage analog design and calibration techniques, respectively, and ii) development of circuit techniques and algorithms to enhance testing and debugging potential to detect errors dynamically, to isolate and confine faults, and to recover errors continuously. The feasibility of the described methods has been verified by measurements from the silicon prototypes fabricated in standard 180nm, 90nm and 65nm CMOS technology.

Covering the essentials of analog circuit design, this book takes a unique design approach based on a MOSFET model valid for all operating regions, rather than the standard square-law model. Opening chapters focus on device modeling, integrated circuit technology, and layout, whilst later chapters go on to cover noise and mismatch, and analysis and design of the basic building blocks of analog circuits, such as current mirrors, voltage references, voltage amplifiers, and operational amplifiers. An introduction to continuous-time filters is also provided, as are the basic principles of sampled-data circuits, especially switched-capacitor circuits. The final chapter then reviews MOSFET models and describes techniques to extract design parameters. With numerous design examples and exercises also included, this is ideal for students taking analog CMOS design courses and also for circuit designers who need to shorten the design cycle.

Integrated circuit technology is widely used for the full integration of electronic systems. In general, these systems are realized using digital techniques implemented in CMOS technology. The low power dissipation, high packing density, high noise immunity, ease of design and the relative ease of scaling are the driving forces of CMOS technology for digital applications. Parts of these systems cannot be implemented in the digital domain and will remain analog. In order to achieve complete system integration these analog functions are preferably integrated in the same CMOS technology. An important class of analog circuits that need to be integrated in CMOS are analog filters. This book deals with very high frequency (VHF) filters, which are filters with cut-off frequencies ranging from the low megahertz range to several hundreds of megahertz. Until recently the maximal cut-off frequencies of CMOS filters were limited to the low megahertz range. By applying the techniques presented in this book the limit could be pushed into the true VHF domain, and integrated VHF filters become feasible. Application of these VHF filters can be found in the field of communication, instrumentation and control systems. For example, pre and post filtering for high-speed AD and DA converters, signal reconstruction, signal decoding, etc. The general design philosophy used in this book is to allow only the absolute minimum of signal carrying nodes throughout the whole filter. This strategy starts at the filter synthesis level and is extended to the level of electronic circuitry. The result is a filter realization in which all capacitators (including parasitics) have a desired function. The advantage of this technique is that high frequency parasitic effects (parasitic poles/zeros) are minimally present. The book is a reference for engineers in research or development, and is suitable for use as a text for advanced courses on the subject. >

1V CMOS Gm-C Filters: Design and Applications discusses the design aspects of transconductor and Gm-C filter circuits, with a special focus on 1V circuit implementations. The emphasis is on high linearity voltage-to-current blocks for wireless and wireline applications, and the designs cover up to very high speed specifications. 1V CMOS Gm-C Filters: Design and Applications provides a clear introduction of low voltage architectures and yields insight into the influence of circuit non-idealities. The fully CMOS implementation could be useful for wireless and wireline applications. The basic design concepts can be easily constructed through the illustration of this book. This book can be provided for engineers and researchers who are interested in the transconductor and Gm-C filter. It is also a good reference for the course related to analog integrated circuit design.