Complex behavior in switching power converters

Power electronics circuits are rich in nonlinear dynamics. Their operation is characterized by cyclic switching of circuit topologies, which gives rise to a variety of nonlinear behavior. This paper provides an overview of the chaotic dynamics and bifurcation scenarios observed in power converter circuits, emphasizing the salient features of the circuit operation and the modeling strategies. In particular this paper surveys the key publications in this field, reviews the main modeling approaches, and discusses the salient bifurcation behaviors of power converters with particular emphasis on the disruption of standard bifurcation patterns by border collisions     

Synchronization and Small-Signal Analysis of Nonlinear Periodic Circuits

Common approaches to simulate the steady-state behavior of nonlinear periodic circuits forced by a periodic signal of small amplitude assume that the forcing signal effects are additive to the steady-state solution of the unperturbed circuit. This assumption leads to the adoption of the variational model of the nonlinear unperturbed circuit. The variational model does not pose any particular problem when dealing with nonautonomous circuits, but must be suitably formulated when autonomous circuits are considered and the frequency of the forcing signal is close to the working frequency of the unperturbed nonlinear circuit. We show that, in this case, synchronization effects must be accounted for, and, as synchronization phenomena are intrinsically nonlinear, it is impossible to take them into account using a variational model. In fact, conventional variational models are derived from the unperturbed nonlinear circuit working at steady state and with a fixed relative phase between perturbation and system, i.e., without any possibility of phase shifts (that is, of any dynamics leading to possible synchronization). In general, this yields inaccurate or even wrong results. In this paper, we investigate this limitation of the approaches based on the variational model. Some simulation results are reported that show the transition between the nonsynchronization region to the synchronization one of well-known simple oscillators, such as the Van der Pol one when the parameters of the small-signal perturbation are varied.     

Low-Frequency Noise Phenomena in Switched MOSFETs

In small-area MOSFETs widely used in analog and RF circuit design, low-frequency (LF) noise behavior is increasingly dominated by single-electron effects. In this paper, the authors review the limitations of current compact noise models which do not model such single-electron effects. The authors present measurement results that illustrate typical LF noise behavior in small-area MOSFETs, and a model based on Shockley-Read-Hall statistics to explain the behavior. Finally, the authors treat practical examples that illustrate the relevance of these effects to analog circuit design. To the analog circuit designer, awareness of these single-electron noise phenomena is crucial if optimal circuits are to be designed, especially since the effects can aid in low-noise circuit design if used properly, while they may be detrimental to performance if inadvertently applied     

Toward nonlinear wave digital filters

The wave digital filter (WDF) theory provides us with a systematic methodology for building digital models of analog filters through the discretization of their individual circuit components. In some situations, WDF principles can also be successfully used for modeling circuits in which a nonlinear circuit element is present under mild conditions on its characteristic. We propose an extension of the classic WDF principles, which allows us to considerably extend the class of nonlinear elements that can be modeled in the wave digital domain. The method we propose is based on a new class of waves that can be chosen in such a may that incorporates the intrinsic dynamics of a nonlinear element into a new class of dynamic multiport adaptors. This family of junctions represents a generalization of the concept of “mutator” in the analog nonlinear circuit theory because it allows us to treat a nonlinear dynamic element as if it were instantaneous (resistive)     

电流激励蔡氏电路混沌的解析预测

考虑到蔡氏电路受周围电路的影响,故将受周围影响的蔡氏电路做了等效处理,并将其等效为电流激励蔡氏电路。这里首次用解析的方法对三阶非线性微分方程能够产生混沌的参数范围进行预测,利用该方法得出电流激励蔡氏电路产生混沌的必要参数条件。通过数值仿真证明了该等效电路具有极其丰富的混沌动力学行为,仿真结果与解析预测结果有较好的吻合性。     

FD-TD modeling of digital signal propagation in 3-D circuits withpassive and active loads

Most existing computer-aided circuit design tools are limited when digital clock speeds exceed several hundred MHz. These tools may not deal effectively with the physics of UHF and microwave electromagnetic wave energy transport along metal surfaces such as ground planes or in the air away from metal paths that are common at or above this frequency range. In this paper, we discuss full-wave modeling of electronic circuits in three dimensions using the finite-difference time-domain (FD-TD) solution of Maxwell's equations. Parameters such as stripline complex line impedance, propagation constant, capacitance per unit length and inductance per unit length can be easily computed as a function of frequency. We also discuss FD-TD Maxwell's equations computational modeling of lumped-circuit loads and sources in 3-D, including resistors and resistive voltage sources, capacitors, inductors, diodes, and transistors. We believe that this approach will be useful in simulating the large-signal behavior of very high-speed nonlinear analog and digital devices in the context of the full-wave time-dependent electromagnetic field     

电力电子电路中非线性现象研究的发展综述

对电力电子电路中的非线性研究的发展近况作了较为全面的叙述。指出了从非线性动力学的角度去研究分叉与混沌行为是今后电力电子电路分析方法的一个发展方向。     

一类电路系统的分岔分析及超混沌控制研究

为了揭示电路系统丰富的非线性动力学行为,提高电路系统的稳定性,避免混沌或超混沌电路对元器件的危害,针对一类电路系统模型,应用现代数学中的微分方程理论和非线性动力学的方法,分析了系统发生分岔的条件,并通过数值分析验证了该理论结果。研究发现系统在一定参数条件下存在内衣马克-沙克分岔和倍周期分岔,随着参数的变化系统演化为混沌和超混沌。针对目前超混沌控制方法的研究较少,而且控制的周期轨道多是低周期轨道,提出一种节约能量并能将系统控制到高倍周期和概周期的方法,为研究许多现实离散系统模型提供了一种新的方法,对于研究电路系统提供了一条新的思路,因而具有一定的理论意义和实用价值。     

基于Matlab/Simulink的单相触发电路的设计与实现

文中基于Matlab／Simulink设计了一个单相可控整流电路的触发电路。并阐述了触发电路的模块化与封装方法。该触发装置在Simulink环境下具有友好的用户界面，使用方便，简化了单相可控整流电路的仿真模型。通过对单相桥式整流电路的仿真，体现了该触发装置在单相可控整流电路仿真中的良好效果。     

Modeling and analysis of power extraction circuits for passive UHF RFID applications

Modeling and analysis of far field power extraction circuits for passive UHF RF identification (RFID) applications are presented. A mathematical model is derived to predict the complex nonlinear performance of UHF voltage multiplier using Schottky diodes. To reduce the complexity of the proposed model, a simple linear ap-proximation for Schottky diode is introduced. Measurement results show considerable agreement with the values calculated by the proposed model. With the derived model, optimization on stage number for voltage multiplier to achieve maximum power conversion efficiency is discussed. Furthermore, according to the Bode-Fano criterion and the proposed model, a limitation on maximum power up range for passive UHF RFID power extraction circuits is also studied.     

应用于无源超高频射频识别卡芯片的能量提取电路建模与分析

Modeling and analysis of far field power extraction circuits for passive UHF RF identification （RFID） applications are presented. A mathematical model is derived to predict the complex nonlinear performance of UHF voltage multiplier using Schottky diodes. To reduce the complexity of the proposed model, a simple linear approximation for Schottky diode is introduced. Measurement results show considerable agreement with the values calculated by the proposed model. With the derived model, optimization on stage number for voltage multiplier to achieve maximum power conversion efficiency is discussed. Furthermore, according to the Bode-Fano criterion and the proposed model, a limitation on maximum power up range for passive UHF RFID power extraction circuits is also studied.     

超高频无源RFID标签的一些关键电路的设计

本文针对超高频无源RFID标签芯片的设计,给出了一些关键电路的设计考虑。文章从UHFRFID标签的基本组成结构入手,先介绍了四种电源恢复电路结构,以及在标准CMOS工艺下制作肖特基二极管来组成倍压电路的解决方案。然后针对电源稳压电路,提出了串联型和并联型两种稳压电路。文章针对ASK包络解调电路,提出了新的泄流源的设计。最后,文章介绍了启动信号产生电路的设计考虑。     

Circuits with Oscillatory Hierarchical Farey Sequences and Fractal Properties

We present two dual oscillating circuits having a wide spectrum of dynamical properties but relatively simple topologies. Each circuit has five bifurcating parameters, one nonlinear element of cubic current–voltage characteristics, one controlled element, LCR components and a constant biasing source. The circuits can be considered as two coupled oscillators (linear and nonlinear) that form dual jerk circuits. Bifurcation diagrams of the circuits show a rather surprising result that the bifurcation patterns are of the Farey sequence structure and the circuits’ dynamics is of a fractal type. The circuits’ fractal dimensions of the box counting (capacity) algorithm, Kaplan–Yorke (Lyapunov) type and its modified (improved) version are all estimated to be between 2.26 and 2.52. Our analysis is based on numerical calculations which confirm a close relationship of the circuits’ bifurcation patterns with those of the Ford circles and Stern–Brocot trees.     

Differential BiCMOS logic circuits: fault characterization anddesign-for-testability

Merged Current Switch Logic (MCSL) and Differential Cascode Voltage Switch Logic (DCVSL) are two common structures for differential BiCMOS logic family, that have several potential applications in high-speed VLSI circuits. This paper studies the fault characterization of these BiCMOS circuits. The impact of each possible single defect on the behavior of the circuits is analyzed by simulation. A new class of faults which is unique to differential circuits is identified and its testability is assessed. We propose a design-for-testability method that facilitates testing of this class of faults. Two different realizations for this method are introduced. The impact of this circuit modification on the behavior of the circuit in normal mode is investigated     

一种用于UHF RFID的低压高效电源产生电路

介绍了一种为无源UHF RFID设计的高效高灵敏度电源产生电路.该电路基于0.18μm工艺,其中包含了两个电荷泵,一个参考电流源和一组偏置电路.由于其偏置电路消除了传统电路中的阈值损失和体效应,使该电路在低压下的电源转换性能得到很大的提高.要为100kΩ负载提供1.5V电源电压,所需最小输入电压为350mV,转换效率为22%.在负载为60kΩ时,最高可以获得29.8%的转换效率.仿真结果表明,新的电路结构比传统的电荷泵具有更优越的性能.     

Low loss and high performance SAW filters for 800 MHz mobile telephone transceiver

Low loss surface acoustic wave (SAW) filters have been developed for use in the radio frequency circuits of the mobile telephone transceiver. Both the UHF (800 MHz) and VHF (90 MHz) band-pass filters have exhibited high performance, and the employment of the SAW filters has shown advantages in UHF/VHF circuit integration for mass production.     

Nonlinear function generators and chaotic signal generators using apulse-width modulation method

A new approach for making arbitrary nonlinear transfer function generator circuits is proposed. Arbitrary non-monotone functions can be made by combining plural pulse-width modulation (PWM) circuits. Chaotic signal generators can be made by using these circuits. This approach is useful for implementing large-scale nonlinear circuit systems     

An all-band TV tuner IC with 10-GHz 100-V mixed analog/digital Sibipolar technology

An all-band TV tuner IC with an on-chip PLL and a high-voltage output stage is developed. The use of a self-aligned bipolar technology called high-voltage compatible sidewall base contact structure (HV-SICOS) allows the integration of 1-GHz analog circuits, 1-GHz low-power ECL-I²L PLL circuits, and a 0.5- to 30-V tuning diode bias current on the same chip. The analog block has a VCO and mixer pair for the VHF/CATV and another pair for the UHF bands, a UHF input amplifier, an IF amplifier, and a VCO signal switching circuit. To suppress the digital noise level for mixed analog/digital mode operation, the PLL is constructed with high-speed ECL circuits for divide-by-four and dual modulus prescalers, and low-power I²L circuits. An isolation area is placed between the analog and digital blocks. Conversion gain of 24 dB for VHF/CATV and 33 dB for UHF, a noise figure of 10 dB, and 1% cross modulation of 95 dB-μV are obtained. This IC operates with a total power dissipation of 200 mW on a 3-mm×4-mm chip     

New precision rectifier circuits with high accuracy and wide bandwidth

Two new circuits for precise full-wave rectification are presented. The first is based on a current feedback amplifier with a new current-mode absolute-value circuit in its feedback loop. The second utilizes an operational conveyor working in conjunction with a current-mode absolute-value circuit in a new configuration. Both circuits have high accuracy and wide bandwidth, giving undistorted rectified waveforms up to 500?kHz in the first case and 1?MHz in the other. Additionally, both systems have high sensitivity, being able to full-wave rectify signals with amplitudes as small as 5?mV peak at 100?kHz. Finally, the new systems have excellent temperature stability, low offset output voltage and are suitable for IC fabrication.     

Inducing Chaos in Electronic Circuits by Resonant Perturbations

We propose a scheme to induce chaotic attractors in electronic circuits. The applications that we are interested in stipulate the following three constraints: 1) the circuit operates in a stable periodic regime far away from chaotic behavior; 2) no parameters or state variables of the circuit are directly accessible to adjustment and 3) the circuit equations are unknown and the only available information is a time series (or a signal) measured from the circuit. Under these conditions, a viable approach to chaos induction is to use external excitations such as a microwave signal, assuming that a proper coupling mechanism exists which allows the circuit to be perturbed by the excitation. The question we address in this paper is how to choose the waveform of the excitation to ensure that sustained chaos (chaotic attractor) can be generated in the circuit. We show that weak resonant perturbations with time-varying frequency and phase are generally able to drive the circuit into a hierarchy of nonlinear resonant states and eventually into chaos. We develop a theory to explain this phenomenon, provide numerical support, and demonstrate the feasibility of the method by laboratory experiments. In particular, our experimental system consists of a Duffing-type of nonlinear electronic oscillator driven by a phase-locked loop (PLL) circuit. The PLL can track the frequency and phase evolution of the target Duffing circuit and deliver resonant perturbations to generate robust chaotic attractors