Oversampled Delta-Sigma Modulators: Analysis, Applications and Novel Topologies

ISBN-13: 9781441953506 / Angielski / Miękka / 2011 / 226 str.

Mücahit Kozak;Izzet Kale

Opis

The analysis of the quantization noise in delta-sigma modulators is not a trivial task. State-of-the-art analysis methods include modelling the quantization noise as a uniform distributed white noise. However, it is not uncommon to observe limit cycle oscillations and tones at the output of a delta-sigma modulator. In most of the applications, these limit cycles and tones are strictly objectionable. Such an application, for instance, is a Fractional-N PLL frequency synthesizer, where idle tones and limit cycles generated from the delta-sigma modulator directly appear in the synthesized RF waveform as spurious components. The relatively small conversion bandwidth is another important limitation of delta-sigma modulators. Due to their oversampling nature, delta-sigma modulators have been used in low frequency applications.
Oversampled Delta-Sigma Modulators: Analysis, Applications, and Novel Topologies presents theorems and their mathematical proofs for the exact analysis of the quantization noise in delta-sigma modulators. Extensive mathematical equations are included throughout the book to analyze both single-stage and multi-stage architectures. It has been proved that appropriately set initial conditions generate tone free output, provided that the modulator order is at least three. These results are applied to the design of a Fractional-N PLL frequency synthesizer to produce spurious free RF waveforms. Furthermore, the book also presents time-interleaved topologies to increase the conversion bandwidth of delta-sigma modulators. The topologies have been generalized for any interleaving number and modulator order.
Oversampled Delta-Sigma Modulators: Analysis, Applications, and Novel Topologies is full of design and analysis techniques. The book contains sufficient detail that enables readers with little background in the subject to easily follow the material in it.
Oversampled Delta-Sigma Modulators: Analysis, Applications, and Novel Topologies will be of interest to graduate students, researchers, and practising circuit designers in the areas of delta-sigma based data converters and Fractional-N PLL frequency synthesizer design.

Recenzje

From the reviews:

"This book describes the principles of operation of oversampled (delta sigma symbol) modulators and gives an exact analysis and speed limitations of these non-linear complex circuits. ... The book should be useful both as a reference book to graduate students, and researchers and practising engineers in the field of mixed-signal VLSI design. After finishing the text, the total picture of design including analysis, modeling, simulation, and implementation of this type of circuits is presented to the reader. ... I highly recommend this book." (Mile Stojcev, Microelectronics Reliability, Vol. 44, 2004)

Spis treści

Preface. 1: Introduction. 1.1. Aims and Motivations. 1.2. Original Contributions. 1.3. Outline of the Research Monograph. 2: Basic Principles of Delta-Sigma Modulation. 2.1. Nyquist Rate Converters. 2.2. Quantization Noise. 2.3. Oversampling Advantage. 2.4. DeltaSigma Modulation. 2.5. Limit Cycle Oscillations and Tones. 2.6. Higher Order DeltaSigma Modulators. 2.7. Multi-Bit DeltaSigma Converters. 2.8. State-of-the-art Analysis. 3: Analysis of Mash Delta-Sigma Modulators with DC Inputs. 3.1. Introduction. 3.2. Non-Linear Difference Equations. 3.3. Statistics of the Quantizer Error Sequence. 3.4. Simulation Results. 3.5. Output Spectrum. 3.6. Digital Realization of Irrational Initial Condition. 3.7. Conclusion. 4: Analysis of Single-Stage Delta-Sigma Modulators with DC Inputs. 4.1. Motivation behind the Work. 4.2. Uniform Quantizer in the No-Overload Region. 4.3. Non-Linear Difference Equations. 4.4. No-Overload Stability Criterion. 4.5. Solution to the Non-Linear Difference Equation. 4.6. Statistics of the Quantizer Error Sequence. 4.7. Fundamental Result. 4.8. Simulation Results. 4.9. Output Spectrum. 4.10. Error-Feedback Topology. 4.11. Conclusion. 5: Fractional-N PLL Frequency Synthesizers. 5.1. Introduction. 5.2. Analysis of PLLs. 5.3. The Fractional-N Concept. 5.4. Design and Simulation of Fractional-N PLL Frequency Synthesizers. 5.5. Pipelined Implementation of Mash &Dgr;&Sgr; Modulators. 5.6. Conclusion. 6: Time-Interleaved Delta-Sigma Modulators. 6.1. Introduction. 6.2. Block Digital Filtering Approach. 6.3. Time-Interleaved &Dgr;&Sgr; Modulators with Reduced Complexity. 6.4. Simulations. 6.5. Implementation Issues. 6.6. Hardware Comparison. 6.7. Higher-Order Time-Interleaved &Dgr;&Sgr; Modulators. 6.8. Zero-Insertion Interpolation Time-Interleaving. 6.9. Further Practical Issues. 6.10. Conclusion. References.