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Understanding Delta-Sigma Data Converters

TL;DR: This chapter discusses the design and simulation of delta-sigma modulator systems, and some of the considerations for implementation considerations for [Delta][Sigma] ADCs.
Abstract: Chapter 1: Introduction.Chapter 2: The first-order delta-sigma modulator.Chapter 3: The second-order delta-sigma modulator.Chapter 4: Higher-order delta-sigma modulation.Chapter 5: Bandpass and quadrature delta-sigma modulation.Chapter 6: Implementation considerations for [Delta][Sigma] ADCs.Chapter 7: Delta-sigma DACs.Chapter 8: High-level design and simulation.Chapter 9: Example modulator systems.Appendix A: Spectral estimation.Appendix B: The delta-sigma toolbox.Appendix C: Noise in switched-capacitor delta-sigma data converters.

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Citations
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Proceedings ArticleDOI
01 Nov 2013
TL;DR: The proposed result overcomes the limitation of a latest method that can deal with NTFs with finite impulse response only and has an advantage over the benchmark one in improving the signal-to-noise ratio.
Abstract: This paper is concerned with the issue of noise shaping of delta-sigma modulators. The shaped noise transfer function (NTF) is assumed to have infinite impulse response (IIR), and the optimization objective is minimizing the maximum magnitude of the NTF over the signal frequency band. By virtue of the generalized Kalman-Yakubovich-Popov lemma, the optimization of NTFs is converted into a minimization problem subject to quadratic matrix inequalities, and then an iterative linear matrix inequality algorithm is proposed to solve this alternative minimization problem. The proposed result overcomes the limitation of a latest method that can deal with NTFs with finite impulse response only. A design example is provided to demonstrate that the proposed design method has an advantage over the benchmark one in improving the signal-to-noise ratio.

7 citations


Cites background or methods from "Understanding Delta-Sigma Data Conv..."

  • ...Problem Statement Noise shaping is the central task of designing ∆Σ modulators [3]....

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  • ...Especially, in the context of ∆Σ modulation, the value of ̟ is determined as ̟ = π OSR for low-pass modulators and ̟ = π 2×OSR for band-pass modulators, where OSR represents oversampling ratio [3]....

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  • ...which is a standard setting for ∆Σ modulator design [3], [8]....

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  • ...To solve this problem, an empirical but commonly-used strategy is to bound the H∞ norm of the NTF below a reasonable level [3], [8], [9], [24]....

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  • ...∆Σ Modulator and Loop Filter Detailed description on ∆Σ modulators can be found in [3], and for convenience, we briefly introduce some related basic concepts here....

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Journal ArticleDOI
TL;DR: This paper intends to review the motivation, to give a tutorial of the state of the art, as well as to introduce a deeper analysis for DSM with interferer robustness, and to analyzes state-of-the-art techniques of modulators with improved interferer rejection.
Abstract: This paper reviews and analyzes the state of the art of Delta-Sigma modulators for receiver applications. Receiver ADCs require not only steadily increased bandwidth, low power and area consumption, but especially face strong interferer signals. These are outside the band of interest, but they most often determine the overall receiver dynamic range and linearity requirements. In order to avoid or at least relax explicit filtering in front of the ADC, Delta-Sigma architectures have been presented with improved robustness to interferers by filtering. This paper intends to review the motivation, to give a tutorial of the state of the art, as well as to introduce a deeper analysis for DSM with interferer robustness. For this, an introduction to the requirements of Delta-Sigma modulators in receivers is given, and a method is introduced which allows to analyze and to scale the internal states meeting the requirements of the interferer scenarios. The paper additionally analyzes state-of-the-art techniques of modulators with improved interferer rejection in order to outline more clearly their possibilities and drawbacks.

7 citations


Cites background or methods from "Understanding Delta-Sigma Data Conv..."

  • ...This way, a rescaling is performed by changing the individual coefficients but without affecting the overall NTF or STF [34]....

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  • ...In most state of the art approaches, this is done by assuming an IB maximum stable amplitude and equalizing the internal nodes accordingly [34]....

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  • ...Even though DSM design tools like [34] allow to scale the internal signal swings, this is done for a full-scale (FS) signals with a fixed frequency, and not for above full-scale OOB signals....

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  • ...The coefficients for this modulator were generated with the “Delta-Sigma toolbox” [34] for a DT prototype, with a noise-gain of two, an oversampling-ratio (OSR) of 32, a 4-bit internal quantization; this DT modulator was subsequently converted into a CT architecture using a NRZ DAC waveform including an excess loop delay (ELD) of ....

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Journal ArticleDOI
TL;DR: A novel method for the digital synthesis of high quality signals by means of one-bit digital-to-analog converters using evolutionary algorithms to analysis of the best binary sequences for signal generation.

7 citations

Journal ArticleDOI
TL;DR: The design of an embedded audio-visual tracking and speech purification system that is able to perform human face tracking, voice activity detection, sound source direction estimation, and speech enhancement in real-time is described.

7 citations

Journal ArticleDOI
TL;DR: In this article, a CMOS-integrated electrochemical biochip for high-performance molecular testing is presented, which includes an array of 32 $\times $ 32 three-electrode voltammetry pixels and on-chip temperature control between 25 and 95 °C.
Abstract: A CMOS-integrated electrochemical biochip for high-performance molecular testing is presented. The system includes an array of 32 $\times $ 32 three-electrode voltammetry pixels and on-chip temperature control between 25 and 95 °C. Each 100 $\mu \text{m}\,\times 100\,\,\mu \text{m}$ pixel includes a CMOS-compatible and chemo-stable amorphous carbon electrode transducer connected to in-pixel $\Sigma \Delta $ current detection circuitry with 280 fA rms input-referred noise (0.1–20 Hz bandwidth) and 93 dB dynamic range (DR). Array-based DNA detection assays are implemented, and successful DNA melt-analysis and real-time label-free DNA hybridization detection are reported.

7 citations


Cites methods from "Understanding Delta-Sigma Data Conv..."

  • ...In each pixel, we implemented the first-order current sensing modulator [25], [26] connector to the WE transductor element, as shown in Fig....

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References
More filters
Journal ArticleDOI
TL;DR: Higher order modulators are shown not only to greatly reduce oversampling requirements for high-resolution conversion applications, but also to randomize the quantization noise, avoiding the need for dithering.
Abstract: Oversampling interpolative coding has been demonstrated to be an effective technique for high-resolution analog-to-digital (A/D) conversion that is tolerant of process imperfections. A novel topology for constructing stable interpolative modulators of arbitrary order is described. Analysis of this topology shows that with proper design of the modulator coefficients, stability is not a limitation to higher order modulators. Furthermore, complete control over placement of the poles and zeros of the quantization noise response allows treatment of the modulation process as a high-pass filter for quantization noise. Higher order modulators are shown not only to greatly reduce oversampling requirements for high-resolution conversion applications, but also to randomize the quantization noise, avoiding the need for dithering. An experimental fourth-order modulator breadboard demonstrates stability and feasibility, achieving a 90-dB dynamic range over the 20-kHz audio bandwidth with a sampling rate of 2.1 MHz. A generalized simulation software package has been developed to mimic time-domain behavior for oversampling modulators. Circuit design specifications for integrated circuit implementation can be deduced from analysis of simulated data. >

399 citations

Journal ArticleDOI
James C. Candy1
TL;DR: It is shown that digital filters comprising cascades of integrate-and-dump functions can match the structure of the noise from sigma delta modulation to provide decimation with negligible loss of signal-to-noise ratio.
Abstract: Decimation is an important component of oversampled analog-to-digital conversion. It transforms the digitally modulated signal from short words occurring at high sampling rate to longer words at the Nyquist rate. Here we are concerned with the initial stage of decimation, where the word rate decreases to about four times the Nyquist rate. We show that digital filters comprising cascades of integrate-and-dump functions can match the structure of the noise from sigma delta modulation to provide decimation with negligible loss of signal-to-noise ratio. Explicit formulas evaluate particular tradeoffs between modulation rate, signal-to-noise ratio, length of digital words, and complexity of the modulating and decimating functions.

342 citations

Journal ArticleDOI
TL;DR: This paper introduces a new method of analysis for deltasigma modulators based on modeling the nonlinear quantizer with a linearized gain, obtained by minimizing a mean-square-error criterion, followed by an additive noise source representing distortion components.
Abstract: This paper introduces a new method of analysis for deltasigma modulators based on modeling the nonlinear quantizer with a linearized gain, obtained by minimizing a mean-square-error criterion [7], followed by an additive noise source representing distortion components. In the paper, input signal amplitude dependencies of delta-sigma modulator stability and signal-to-noise ratio are analyzed. It is shown that due to the nonlinearity of the quantizer, the signal-to-noise ratio of the modulator may decrease as the input amplitude increases prior to saturation. Also, a stable third-order delta-sigma modulator may become unstable by increasing the input amplitude beyond a certain threshold. Both of these phenomena are explained by the nonlinear analysis of this paper. The analysis is carried out for both dc and sinusoidal excitations.

284 citations

Book ChapterDOI
James C. Candy1, O. Benjamin1
TL;DR: Simple algebraic expressions for this modulation noise and its spectrum in terms of the input amplitude are derived and can be useful for designing oversampled analog to digital converters that use sigma-delta modulation for the primary conversion.
Abstract: When the sampling rate of a sigma-delta modulator far exceeds the frequencies of the input signal, its modulation noise is highly correlated with the amplitude of the input. We derive simple algebraic expressions for this noise and its spectrum in terms of the input amplitude. The results agree with measurements taken on a breadboard circuit. This work can be useful for designing oversampled analog to digital converters that use sigma-delta modulation for the primary conversion.

255 citations

Journal ArticleDOI
01 Mar 1993
TL;DR: The modulator of a bandpass analog/digital (A/D) converter, with 63 dB signal/noise for broadcast AM bandwidth signals centered at 455 kHz, has been implemented by modifying a commercial digital-audio sigma-delta ( Sigma Delta ) converter.
Abstract: The modulator of a bandpass analog/digital (A/D) converter, with 63 dB signal/noise for broadcast AM bandwidth signals centered at 455 kHz, has been implemented by modifying a commercial digital-audio sigma-delta ( Sigma Delta ) converter. It is the first reported fully monolithic implementation of bandpass noise shaping and has applications to digital radio. >

211 citations