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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 34 (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.
On the Stability of Sigma Delta Modulators
 IEEE TRANSACTLONS ON SIGNAL PROCESSING, VOL. 41. NO. 7. JULY 1993
, 1993
"... In this paper we propose a framework for stability analysis of EA modulators, and argue that limit cycles for constant inputs are natural objects to investigate in this context. We present a number of analytical and approximate techniques to aid the stability analysis of the double loop and interpol ..."
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Cited by 26 (2 self)
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In this paper we propose a framework for stability analysis of EA modulators, and argue that limit cycles for constant inputs are natural objects to investigate in this context. We present a number of analytical and approximate techniques to aid the stability analysis of the double loop and interpolative modulators, and use these techniques to propose ways of improved design that explicitly take stability into account.
Estimating from Outputs of Oversampled DeltaSigma Modulation
"... . Oversampling a deltasigmamodulated sequence, one can compute unbiased sample estimates of averages of consecutive input elements for a wide variety of inputs. We prove that these estimates are most efficient in their class (that is, variances of sample means are minimum in the class of random bi ..."
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Cited by 1 (0 self)
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. Oversampling a deltasigmamodulated sequence, one can compute unbiased sample estimates of averages of consecutive input elements for a wide variety of inputs. We prove that these estimates are most efficient in their class (that is, variances of sample means are minimum in the class of random binary sequences g n , n = 1; : : : ; N , such that the expected values of g n are equal to the values of the corresponding inputs of deltasigma modulation) and consistent. Deltasigma modulation may also be described as onedimensional error diffusion (a technique for digital halftoning). However, deltasigma modulation is not a practical digital halftoning algorithm, because human vision averages small luminance deviations in two dimensions. We pose an open problem that invites the reader to extend our approach to the twodimensional case for the purpose of development of a practical digital halftoning algorithm. IEEE EDICS number: SP 3.8.2 Correspondence should be sent to: Dmitri A. Guse...
Stochastic Analysis of the ΣΔ Modulator and Differential Pulse Code Modulator
, 1997
"... One of the most popular systems for performing high resolution analog to digital conversion is the modulator. Though common in applications, theoretical analysis of the modulator is difficult due to the presence of a discontinuous quantizer in the modulator. This paper presents asymptotic resu ..."
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One of the most popular systems for performing high resolution analog to digital conversion is the modulator. Though common in applications, theoretical analysis of the modulator is difficult due to the presence of a discontinuous quantizer in the modulator. This paper presents asymptotic results regarding the statistical behavior of the modulator when inside the loop dithering is utilized. In some recent papers examining the stochastic behavior of the 61; it was shown (via simulations) that the input to the quantizer can be accurately modeled as a stationary Gaussian process. Our analysis shows that both the input to the quantizer and the quantization noise are asymptotically stationary Gaussian processes, under mild assumptions on the input and the dither process. The results of this paper are derived by letting the quantizer stepsize approach zero, and the analytical approach is related to the stochastic analysis of adaptive filtering algorithms. Our analysis is valid for a large collection of stochastic input signals, including ARMA processes. Furthermore, previous stochastic analysis assumed that the quantizer never overloaded, while the present analysis does not make this assumption. It is also shown that analysis of the Differential Pulse Code Modulator is in fact analogous to the analysis of the modulator. Simulation results presented for the firstorder modulator and two secondorder modulators demonstrate the practicality of the analysis.
AN AUDIO ENGINEERING SOCIETY PREPRINTOversampled Analogue.toDigital Conversion for Digital Audio Systems
, 1988
"... Thispreprinthasbeenreproducedfromthe author'sadvance manuscript,withoutediting,correctionsorconsiderationby theReviewBoard.TheAES takesno responsibility forthe contents. Additionalpreprintsmay be obtainedby sendingrequest andremittanceto theAudioEngineeringSocie _ 60 East 42ndStreet,New York,Ne ..."
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Thispreprinthasbeenreproducedfromthe author'sadvance manuscript,withoutediting,correctionsorconsiderationby theReviewBoard.TheAES takesno responsibility forthe contents. Additionalpreprintsmay be obtainedby sendingrequest andremittanceto theAudioEngineeringSocie _ 60 East 42ndStreet,New York,New York10165,USA. Al/rightsreserved.Reproductionof thispreprint,or any portionthereof,isnotpermittedwithoutdirectpermission fromtheJournalof theAudioEngineeringSociety.
A Simple Signal Shaper for GMSK/GFSK and MSK Modulator Based on SigmaDelta Lookup Table
"... Abstract. Due to wide power spectrums of rectangular data streams, it is important for baseband signals to be heavily band limited before modulation. That can be achieved by pulse shaping of rectangular bits. Some of the most common are a halfsine pulse shaper and a Gaussian pulse shaper which are ..."
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Abstract. Due to wide power spectrums of rectangular data streams, it is important for baseband signals to be heavily band limited before modulation. That can be achieved by pulse shaping of rectangular bits. Some of the most common are a halfsine pulse shaper and a Gaussian pulse shaper which are used in Minimum Shift Keying (MSK), Gaussian Minimum Shift Keying (GMSK) and Gaussian Frequency Shift Keying (GFSK) modulations, respectively. The most common solutions of such shapers use PCM based lookuptable (LUT), which requires an nbit D/A converter. We proposed the use of a 1bit Sigma Delta Modulation (SDM) LUT, which results in smaller ROM capacity, a 1bit wide output word, and a simple1bit D/A converter realized as an outofchip firstorder lowpass RC filter, or an inchip charge pump. This article
AntiCorrelation Digital Halftoning
"... A new class of digital halftoning algorithms is introduced. Anticorrelation digital halftoning (ACDH) combines the idea of a wellknown game, Russian roulette, with the statistical approach to bilevel quantization of digital images. A representative ofthe class, serpentine anticorrelation digital h ..."
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A new class of digital halftoning algorithms is introduced. Anticorrelation digital halftoning (ACDH) combines the idea of a wellknown game, Russian roulette, with the statistical approach to bilevel quantization of digital images. A representative ofthe class, serpentine anticorrelation digital halftoning, is described and compared to error di usion, ordered dither, and other important digital halftoning techniques. Serpentine ACDH causes fewer unpleasant correlated artifacts and less contouring than the benchmark algorithms. The quantization noise spectra associated with serpentine ACDH possess bene cial characteristics related to properties of the vision system. The term \violet noise " is proposed to describe quantization noise with stronger bias in favor of highfrequency components than that of blue noise. Novel techniques for color visualization of the noise spectra and the corresponding phase spectra are introduced, and the relative signi cance of the magnitudes and phases of the discrete Fourier transform of the quantization noise is studied. Unlike popular algorithms based on error di usion, serpentine ACDH does not enhance edges. This is good for applications to digital holography and medical imaging. A simple input preprocessing technique allowsonetointroduce edge enhancement if desired, while keeping it more isotropic than that of error di usion. The relation between unwanted transient boundary e ects and edge enhancement accompanying error di usion is examined, and approaches to reduction of boundary e ects are considered. Serpentine ACDH does not cause signi cant boundary e ects. The average intensity representation by di erent algorithms is studied for constant input levels (serpentine ACDH does remarkably well). Prospects for ACDH research are discussed.
Statistical Analysis of FirstOrder BangBang PhaseLocked Loops Using SignDependent Random Walk Theory
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Walid Emar,Issam Ttrad & Rateb AlIssa A Novel Topology Of Delta Modulation Technique For Improving The Power Factor Of AcDc Converters
"... This work presents a new topology of delta modulation technique. This kind of modulation technique is usually used to improve the power factor of Pulse Width Modulation (PWM) converters used for supplying A.C. drives. Many new topologies have been presented trying to obtain a costeffective solution ..."
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This work presents a new topology of delta modulation technique. This kind of modulation technique is usually used to improve the power factor of Pulse Width Modulation (PWM) converters used for supplying A.C. drives. Many new topologies have been presented trying to obtain a costeffective solution to reduce the input current harmonic content and to make it sinusoidal and in phase with the input voltage of ACDC converters. Each one of them has its application range due to the inherent characteristics of the topology (See [23]). Obviously, not every converter is useful for the same application. Hence, this paper tries to show the most appropriate topology of different variants of modulation technique used for power factor correction. This technique which is used to generate the PWM control signals for the main devices of the PWM converter has the advantage of yielding instantaneous current control, resulting in a fast response [3], [4]. However, the switching frequency is not constant and varies over a wide range during each halfcycle of the A.C. input voltage. Furthermore, the frequency is also sensitive to the values of the circuit components, which is also addressed in this paper. This new delta modulation technique topology proves to give great stability performance over other variants of delta modulation or other modulation techniques.
from Conacyt México. Sliding Mode ∑ ∆ Modulation Control of the Boost Converter
, 2004
"... A switched implementation of average dynamic output feedback laws trough a Σ∆modulator, widely known in the classic communications and analog signal encoding literature, not only frees the sliding mode control approach from state measurements and the corresponding synthesis of sliding surfaces in ..."
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A switched implementation of average dynamic output feedback laws trough a Σ∆modulator, widely known in the classic communications and analog signal encoding literature, not only frees the sliding mode control approach from state measurements and the corresponding synthesis of sliding surfaces in the plant’s state space, but it also allows to effectively transfer all desired closed loop features of an uniformly bounded, continuous, average output feedback controller design into the more restrictive discrete valued (ONOFF) control framework of a switched system. The proposed approach is here used for the inputoutput sliding mode stabilization of the “boost " DCtoDC converter. This is achieved by means of a well known passivity based controller but any other output feedback design would have served our purposes. This emphasizes the flexibility of the proposed sliding mode control design implementation through Σ∆modulators.