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A CMOS Area Image Sensor With Pixel Level A/D Conversion
 IN ISSCC DIGEST OF TECHNICAL PAPERS
, 1995
"... A CMOS 64 x 64 pixel area image sensor chip using SigmaDelta modulation at each pixel for A/D conversion is described. The image data output is digital. The chip was fabricated using a 1.2µm two layer metal single layer poly nwell CMOS process. Each pixel block consists of a phototransistor and ..."
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Cited by 27 (7 self)
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A CMOS 64 x 64 pixel area image sensor chip using SigmaDelta modulation at each pixel for A/D conversion is described. The image data output is digital. The chip was fabricated using a 1.2µm two layer metal single layer poly nwell CMOS process. Each pixel block consists of a phototransistor and 22 MOS transistors. Test results demonstrate a dynamic range potentially greater than 93dB, a signal to noise ratio (SNR) of up to 61dB, and dissipation of less than 1mW with a 5V power supply.
A/D Conversion with Imperfect Quantizers
 IEEE Transactions on Information Theory, Volume 52, Issue
, 2006
"... We analyze mathematically the effect of quantization error in the circuit implementation of Analog to Digital (A/D) converters such as Pulse Code Modulation (PCM) and Sigma Delta Modulation (Σ∆). Σ ∆ modulation, which is based on oversampling the signal, has a self correction for quantization error ..."
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Cited by 11 (1 self)
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We analyze mathematically the effect of quantization error in the circuit implementation of Analog to Digital (A/D) converters such as Pulse Code Modulation (PCM) and Sigma Delta Modulation (Σ∆). Σ ∆ modulation, which is based on oversampling the signal, has a self correction for quantization error that PCM does not have, and that we believe to be a major reason why Σ ∆ modulation is preferred over PCM in A/D converters with imperfect quantizers. Motivated by this, we construct other encoders that use redundancy to obtain a similar self correction property, but that achieve higher order accuracy relative to bit rate than “classical ” Σ∆. More precisely, we introduce two different types of encoders that exhibit exponential bit rate accuracy (in contrast to the polynomial rate of classical Σ∆) and still retain the self correction feature.
Deterministic Analysis of Oversampled A/D Conversion and Sigma/Delta Modulation, and Decoding Improvements using Consistent Estimates
, 1993
"... Analogtodigital conversion (ADC) which consists in a double discretization of an analog signal in time and in amplitude is increasingly used in modern data acquisition. However, the conversion process always implies some loss of information due to amplitude quantization. Oversampling is the techni ..."
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Cited by 7 (0 self)
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Analogtodigital conversion (ADC) which consists in a double discretization of an analog signal in time and in amplitude is increasingly used in modern data acquisition. However, the conversion process always implies some loss of information due to amplitude quantization. Oversampling is the technique currently used to reduce this loss of accuracy. The error reduction can be performed by lowpass filtering the quantized signal, thus eliminating the high frequency components of the quantization error signal. This is the classical method used to reconstruct the analog signal from its oversampled and quantized version. This reconstruction scheme yields a mean squared error (MSE) inversely proportional to the oversampling ratio R. The fundamental question pursued in this thesis is the following: how much information is available in the oversampled and quantized version of a bandlimited signal for its reconstruction? In order to identify this information, it is essential to go back to the original description of quantization which is typically deterministic. We show that a reconstruction scheme fully takes this information into account
NOISE SHAPING IN AN ITUT G.711INTEROPERABLE EMBEDDED CODEC
"... In the transition from narrowband to wideband speech communications, there is a need in some applications for a high quality wideband coding scheme interoperable with the ITUT G.711 narrowband coding standard. This can be accomplished using a multilayer coding scheme with a G.711 compatible core l ..."
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Cited by 1 (1 self)
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In the transition from narrowband to wideband speech communications, there is a need in some applications for a high quality wideband coding scheme interoperable with the ITUT G.711 narrowband coding standard. This can be accomplished using a multilayer coding scheme with a G.711 compatible core layer. For optimal wideband quality in the upper layers, this requires using full frequency range (504000 Hz instead of 3003400Hz) in the core layer. In this context, the 8bit nonuniform PCM quantizer of the ITU–T G.711 standard can produce highly perceptible noise. The purpose of this paper is to demonstrate how efficient noise masking can be applied at the encoder in a G.711interoperable manner, and how the same noise masking can be extended at the decoder to one or more enhancement layers to implement a perceptually optimized multilayer codec. 1.
unknown title
"... Abstract—Design techniques for 61 modulators from communications are applied and adapted to improve the spectral characteristics of high frequency power electronic applications. A high frequency power electronic circuit can be regarded as a quantizer in an interpolative 61 modulator. We review one d ..."
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Abstract—Design techniques for 61 modulators from communications are applied and adapted to improve the spectral characteristics of high frequency power electronic applications. A high frequency power electronic circuit can be regarded as a quantizer in an interpolative 61 modulator. We review one dimensional 61 modulators and then generalize to the hexagonal sigmadelta modulators that are appropriate to threephase converters. A range of interpolative modulator designs from communications can then be generalized and applied to power electronic circuits. White noise spectral analysis of sigmadelta modulators is generalized and applied to analyze the designs so that the noise can be shaped to design requirements. Simulation results for an inverter show significant improvements in spectral performance. Index Terms—Ergodic, power electronics, quantization, 61 modulation, spectral analysis, voltage source inverter (VSI).
DESIGN OF ROBUST AND FLEXIBLE ONCHIP ANALOGTODIGITAL CONVERSION ARCHITECTURE Approved by:
, 2004
"... To the greatest engineer ..."
Hexagonal Sigma Delta Modulators in Power Electronics
, 2003
"... Design techniques for sigmadelta modulators from communications are applied and adapted to improve the spectral characteristics of high frequency power electronic applications. A high frequency power electronic circuit can be regarded as a quantizer in an interpolative ΣΔ modula ..."
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Design techniques for sigmadelta modulators from communications are applied and adapted to improve the spectral characteristics of high frequency power electronic applications. A high frequency power electronic circuit can be regarded as a quantizer in an interpolative &Sigma;&Delta; modulator. We review one dimensional sigmadelta modulators and then generalize to the hexagonal sigmadelta modulators that are appropriate to threephase converters. A range of interpolative modulator designs from communications can then be generalized and applied to power electronic circuits. White noise spectral analysis of sigmadelta modulators is generalized and applied to analyze the designs so that the noise can be shaped to design requirements. Simulation results for an inverter show significant improvements in spectral performance.
Quantization Noise in ΔΣ A/D Converters
, 1995
"... Introduction The heart of a \Delta\Sigma modulator and any other analogtodigital converter (ADC) is a quantizer, a device which maps real numbers into a finite set of possible representative values, often as few as two. Any analysis of the behavior of a \Delta\Sigma modulator must include consider ..."
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Introduction The heart of a \Delta\Sigma modulator and any other analogtodigital converter (ADC) is a quantizer, a device which maps real numbers into a finite set of possible representative values, often as few as two. Any analysis of the behavior of a \Delta\Sigma modulator must include consideration of the behavior of the quantizer. The quantization operation is inherently nonlinear and hence rigorous analysis is complicated even in the simplest of systems. When quantizers are incorporated into linear systems with feedback such as \Delta\Sigma modulators and bangbang control systems, the analysis becomes even more difficult. Simulations cannot capture all aspects of possible system behavior and are not always reproducible as different random number generators are used and care is not always taken to ensure that sample functions are long enough for sample averages to be close to expectations with high probability. As a result, various methods based on approximations have
Error Spectrum Shaping
 Duke University
, 1988
"... CONTENTS ACKNOWLEDGMENT............................................................................................iii TABLE OF CONTENTS........................................................................................... iv LIST OF TABLES ..................................................... ..."
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CONTENTS ACKNOWLEDGMENT............................................................................................iii TABLE OF CONTENTS........................................................................................... iv LIST OF TABLES .................................................................................................... vii LIST OF FIGURES ................................................................................................... ix SUMMARY...............................................................................................................xiii CHAPTER PAGE 1. INTRODUCTION ................................................................................................... 1 Goals & Motivation ................................................................................................... 2 Research Overview .................................................................................................... 4 Thesis Organization .............
[6] E. Parzen, “Multiple time series Modeling, ” in Multivariate Analp
, 1970
"... [7] W. C. Kellog, “Time domain design of nonrecursive least meansquare digital filters, ” IEEE Trans. Audio Electroacoust., vol. ..."
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[7] W. C. Kellog, “Time domain design of nonrecursive least meansquare digital filters, ” IEEE Trans. Audio Electroacoust., vol.