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Asian Solid-State Circuits Conference (A-SSCC)

作者： Huang, Chenling Sarkar, Pikul Chakrabartty, Shantanu Michigan State Univ Dept Elect & Comp Engn E Lansing MI 48824 USA

Hot-electron injection is widely used for accurate programming of on-chip floating-gate voltage and current references. The conventional programming approach involves adapting the duration and magnitude of the injection pulses based on a predictive model which is estimated by using measured data. However, varying the pulse-widths or amplitudes introduces nonlinearity in the injection process which complicates the modeling, calibration and programming procedure. In this paper, we propose a linear hot-electron injection technique which significantly simplifies the programming procedure, and can achieve programming accuracy greater than 13-b which is limited by the thermal noise from the injection process. The procedure employs an active feedback circuit which ensures that all the nonlinear factors affecting the hot-electron injection process are held constant, thus achieving a stable and controllable injection rate. Measured results using an array of floating-gate voltage reference prototyped in a 0.5-mu m standard CMOS process demonstrate that the injection rates can be controlled from 0.1 to 4.1 Vfor the programmable voltage range. Using 50-ms injection pulses, we show that the average injection rate can be adapted from 6.9 to 250 mu V/cycle.

关键词： Adaptive programming floating-gate transistor hot-electron injection injection rate pulse-width modulation

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Optimized Coding Scheme for Class-S Amplifiers

Optimized Coding Scheme for Class-S Amplifiers

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41st European Microwave Conference (EuMC)

作者： Wentzel, Andreas Meliani, Chafik Heinrich, Wolfgang Ferdinand Braun Inst FBH D-12489 Berlin Germany

ISBN: (纸本)9782874870224

This paper is based on a voltage-mode class-S power amplifier for the 450 MHz band using GaN-MMICs. To optimize back-off performance, the conventional topology is modified and the circuit is operated using different coding schemes for the input signal. While for the classical band-pass delta-sigma modulation, a peak output power of 2.3 W with 38% drain efficiency is obtained, tests using a pulse-width modulation approach yield significant improvements, with a maximum output power of 3 W with more than 80% drain efficiency. At 6 dB and 1 0 dB power back-off, 60% and 40% efficiency are achieved, respectively.

关键词： Microwave power amplifiers class-S switch-mode delta-sigma modulation pulse-width modulation GaN MMIC

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Harmonic current control in a high-power current source rectifier system

Harmonic current control in a high-power current source rect...

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作者： Zhou, Hua University of Alberta

学位级别：master

Line current distortion is an important issue to a high-power current source rectifier(CSR) system. There are two main challenges related to this issue. First, the CSR input LC resonance can be affected by the variation of the source inductance from the power system and the effects of the CSR DC side circuit, which may lead to a line current distortion higher than expected. Another challenge is that the traditional high-power CSR using Selective Harmonic Elimination (SHE) pulse-width modulation (PWM) technique attempts to eliminate certain harmonics in the PWM current, which limits its ability for line current harmonic control. To control the CSR line current harmonics, this thesis focuses on two aspects: 1) the analysis and design of CSR input filter to avoid unexpected input LC resonance, and 2) the development of a new PWM scheme that can compensate the effects of the grid voltage harmonics and DC link current ripples. The thesis work has been validated by simulations and on an experimental CSR prototype

关键词： Current source rectifier Harmonic control pulse-width modulation Total harmonic distortion Filter design

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DEVICE APPLICATION OF NON-EQUILIBRIUM MOS CAPACITORS FABRICATED ON HIGH RESISTIVITY SILICON

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INTERNATIONAL JOURNAL ON SMART SENSING AND INTELLIGENT SYSTEMS 2011年第4期4卷 686-697页

作者： Malik, O. De la Hidalga-W, F. J. INAOE Dept Elect Puebla Mexico

This work shows that the direct pulse-wide-modulated (PWM) output electric signal, with a duty cycle controlled by light intensity, can be obtained using a circuit that contains a saw-tooth voltage generator connected in series with a dc voltage source and a metal (semitransparent gate) oxide semiconductor capacitor (MOS-C) operating in non-equilibrium mode. Amplified output signal presents positive and negative PWM waveforms that can be easily separated using diodes. The duty of the positive part is proportional to the light intensity, whereas for the negative part is inversely proportional to the intensity. The frequency operating range of this proposed instrument varies from 1 Hz to a few kilohertz. The duty cycle of the PWM output signal varies from 2 to 98 % when the incident light intensity is varying in the microwatts range. This new transducer could be useful for automatic control, robotic applications, dimmer systems feedback electronic systems, and non-contact optical position sensing for nulling and centering measurements. The detailed description of the physical and operating principles of this invented transducer are presented.

关键词： MOS-capacitor silicon pulse-width modulation nulling and centering measurements

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Impact of finite impulse response digital-to-analogue converter delay on the stability of continuous-time sigma-delta modulators with pulse-with modulation in the feedback path

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IET CIRCUITS DEVICES & SYSTEMS 2010年第3期4卷 218-226页

作者： Colodro, F. Torralba, A. Univ Seville Dept Elect Engn Escuela Tecn Super Ingenieros Seville 41092 Spain

A finite impulse response (FIR) digital-to-analogue converter (DAC) in the feedback path has been shown to reduce the sensitivity to clock jitter of continuous-time sigma-delta modulators (SDMs). A method to analyse the impact of the additional loop delay introduced by the FIR-DAC on the modulator stability is proposed in this paper. This method is applied to the pulse width modulated (PWM) SDM. As in the PWM-SDM the pulse-width modulator is sampled at a frequency higher than the quantiser, a discrete time model is first obtained which operates with only one clock. The stability analysis is based on a linear model with a new criterion which takes into account the quantiser overloading. The theoretical results are in accordance with the results obtained by simulation. Here, it is shown that PWM-SDMs with an order greater than 2 can be designed maintaining the low sensitivity of multiple feedback architectures to a delay in the outer loop.

关键词： pulse-width modulation sigma-delta modulation finite impulse response digital-to-analogue converter continuous-time sigma-delta modulators loop delay quantiser overloading continuous time filters stability analysis FIR filters pulse width modulation discrete time model feedback path circuit feedback

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Trajectory Planning for Spacecraft Rendezvous with On/Off Thrusters *

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IFAC Proceedings Volumes 2011年第1期44卷 8473-8478页

作者： Rafael Vazquez Francisco Gavilan Eduardo F. Camacho Departamento de Ingenieria Aerospacial Departamento de Ingenieria de Sistemas y Automatica Universidad de Sevilla Camino de los Descubrimientos s/n 41092 Sevilla Spain

Abstract The objective of this work is to present a trajectory planning algorithm for spacecraft rendezvous that is able to incorporate pulse-width Modulated (PWM) control signals. The algorithm is based on linearization around a previously computed solution. To initialize the algorithm, a first solution needs to be obtained. To do so, the trajectory planning problem is solved using pulse-Amplitude Modulated (PAM) control signals; these are then converted to PWM signals, which are used as an initial guess. Iterating, the solution is refined until an optimal value is reached. Simulations show that this method converges after a few iterations. The algorithm is simple and fast, hence it could be implemented online or used together with a Model Predictive Controller.

关键词： Spacecraft autonomy Space robotics pulse-width modulation Trajectory planning Optimal trajectory Linearization

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pulse-width modulation pre-emphasis applied in a wireline transmitter, achieving 33 dB loss compensation at 5-Gb/s in 0.13-μm CMOS

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IEEE JOURNAL OF SOLID-STATE CIRCUITS 2006年第4期41卷 990-999页

作者： Schrader, JR Klumperink, EAM Visschers, JL Nauta, B Univ Twente CTIT Res Inst IC Design Grp NL-7500 AE Enschede Netherlands Natl Inst Nucl Phys & High Energy Phys NIKHEF NL-1098 SJ Amsterdam Netherlands

A transmitter pre-emphasis technique for copper cable equalization is presented that is based on pulse-width modulation (PWM). This technique is an alternative to the usual 2-tap symbol-spaced FIR (SSF) pre-emphasis. The technique uses timing resolution instead of amplitude resolution to adjust the filter transfer function, and therefore fits well with future high-speed low-voltage CMOS processes. Spectral analysis and time domain simulations illustrate that PWM pre-emphasis offers more relative high frequency boost than 2-tap SSF. Only one coefficient needs to be set to fit the equalizer transfer function to the channel, which makes convergence of an algorithm for automatic adaptation straightforward. A proof-of-concept 0.13-mu m CMOS transmitter achieves in excess of 5 Gb/s (2-PAM) over 25 m of standard RG-58U low-end coaxial copper cable with 33 dB of channel loss at the Nyquist frequency (2.5 GHz). Measured BER at this speed and channel loss is < 10(-12).

关键词： CMOS integrated circuits copper equalizers pulse-width modulation transceivers transmit pre-emphasis transmit pre-shaping wire communication

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A Class-E PA With pulse-width and pulse-Position modulation in 65 nm CMOS

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IEEE JOURNAL OF SOLID-STATE CIRCUITS 2009年第6期44卷 1668-1678页

作者： Walling, Jeffrey S. Lakdawala, Hasnain Palaskas, Yorgos Ravi, Ashoke Degani, Ofir Soumyanath, Krishnamurthy Allstot, David J. Univ Washington Dept Elect Engn Seattle WA 98195 USA Intel Corp Hillsboro OR 97124 USA

A class-E power amplifier (PA) utilizes differential switches and a tuned passive output network improves power-added efficiency (PAE) and insensitivity to amplitude variations at its input. A modulator is introduced that takes outphased waveforms as its inputs and generates a pulse-width and pulse-position modulated (PWPM) signal as its output. The PWPM modulator is used in conjunction with a class-E PA to efficiently amplify constant envelope (e.g., GMSK) and non-constant envelope (e.g., QPSK, QAM, OFDM) signals with moderate peak-to-average ratios (PAR). The measured maximum output power of the PA is 28.6 dBm with a PAE of 28.5%, and the measured error vector magnitude (EVM) is 1.2% and 4.6% for GMSK and pi/4-DQPSK (PAR approximate to 4 dB) modulated signals, respectively.

关键词： Class-E linearization outphasing power-added efficiency power amplifier pulse-position modulation pulse-width modulation

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pulse-width modulation pre-emphasis applied in a wireline transmitter, achieving 33 dB loss compensation at 5-Gb/s in 0.13-μm CMOS

Pulse-width modulation pre-emphasis applied in a wireline tr...

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Symposium on VLSI Circuits

关键词： CMOS integrated circuits copper equalizers pulse-width modulation transceivers transmit pre-emphasis transmit pre-shaping wire communication

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Optimized modulation for AC-DC Harmonic Immunity in VSC HVDC Transmission

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IEEE TRANSACTIONS ON POWER DELIVERY 2010年第3期25卷 1713-1720页

作者： Flourentzou, Nikolas Agelidis, Vassilios. G. Univ Sydney Sch Elect & Informat Engn Sydney NSW 2006 Australia

Control methods based on selective harmonic elimination pulse-width modulation (SHE-PWM) techniques offer the lowest possible number of switching transitions. This feature also results in the lowest possible level of converter switching losses. For this reason, they are very attractive techniques for the voltage-source-converter-(VSC) based high-voltage dc (HVDC) power transmission systems. The paper discusses optimized modulation patterns which offer controlled harmonic immunity between the ac and dc side. The application focuses on the conventional two-level converter when its dc-link voltage contains a mix of low-frequency harmonic components. Simulation and experimental results are presented to confirm the validity of the proposed switching patterns.

关键词： Amplitude modulation (AM) dc-ac power conversion harmonic control HVDC insulated-gate bipolar transistor (IGBT) power electronics power transmission system pulse-width modulation voltage-source converter (VSC)

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