Numerical state-space average-value modeling of PWM DC-DC converters operating in DCM and CCM

State-space average-value modeling of pulsewidth modulation converters in continuous and discontinuous modes has received significant attention in the literature, and various models have been developed. This paper presents a new approach for generating the state-space average-value model. In the proposed methodology, the so-called duty-ratio constraint and the correction term are extracted numerically using the detailed simulation and are expressed as nonlinear functions of the duty cycle and average-value of the fast state variable. The parasitic effects of circuit elements are readily included. The resulting average-value model is compared to a hardware prototype, a detailed simulation, and several previously published models. The proposed model is shown to be very accurate in predicting the large-signal time-domain transients as well as the small-signal frequency-domain characteristics.     

无源非线性延迟锁定保护电路的分析

本文提出一种简单的无源非线性延迟锁定保护电路，它除具有由复杂的数字逻辑电路构成的计数式延迟锁定保护电路的功能外，对实际工程上常用的ｒｃ低通电路相关处理情况，还优于后者。本文分析了无源非线性延迟锁定保护电路的性能，给出了理想积分和ｒｃ低通电路相关处理两种情况下的确定保持时间的均值和方差，奠定了这种保护系统的理论基础。     

The circuit realization of Mexican Hat wavelet function

A wavelet network circuit implementation for Mexican Hat mother wavelet has been proposed for nonlinear function approximation which can also be used for the realization of the algebraic nonlinear components. The Mexican Hat mother wavelet function has been implemented with discrete circuit components and it has been observed that the experimental waveform obtained from the realized circuit is approximately same as the Spice simulation of the original function. The circuit simulations of exemplar functions implemented in Spice are also given.     

非线性RLC电路的频响特性与稳定性分析

针对非线性RLC电路的频响特性和周期解稳定性等问题,建立了电感非线性RLC串联电路的动力学方程。利用谐波平衡法,导出了电感非线性RLC串联电路的频率响应方程,研究了频率响应特性曲线的跳跃和滞后现象及其不产生谐振现象的条件;分析了该电路周期解的稳定性,得出了稳定区和不稳定区的分界线方程;讨论了非线性因素的影响,得出了忽略RLC串联电路的电感非线性因素的条件。     

Effects of UHF stimulus and negative feedback on nonlinear circuits

We investigate the combined effect of rectification and nonlinear dynamics on the behavior of several simple nonlinear circuits. We consider the classic resistor-inductor-diode (RLD) circuit driven by a low-frequency (LF) source when an operational amplifier with negative feedback is added to the circuit. Ultra-high-frequency (UHF) signals are applied to the circuit, causing significant changes in the onset of LF period doubling and chaos. Measurements indicate that this effect is associated with a dc voltage induced by rectification of the UHF signal in the circuit. The combination of rectification and nonlinear circuit dynamics produce qualitatively new behavior, which opens up a new channel of radio frequency interference in circuits.     

Integrated 1 V thermal shutdown circuit

A 1 V thermal shutdown circuit for the protection of electronic circuits against undesired power dissipation is presented. The circuit functions as a nonlinear current modifier which cuts the bias current of the main circuit down to zero at temperatures above 130 degrees C. The voltage coefficient is 0.5 degrees C/V and the untrimmed accuracy is 7 degrees C.<>     

一种学习速率自适应的可编程片上学习BP神经网络电路系统的设计

设计了一种学习速率自适应的可编程片上学习BP神经网络电路系统.整个系统由前向网络、误差反传网络两部分组成.提出了一种新型的可编程S型函数及其导数的发生器电路.它不仅产生S型函数,完成非线性I－V转换;还利用前向差分法,产生S型函数的导数.这两种函数不仅与理想函数的拟合程度很好,而且易实现对阈值和增益因子的编程.为提高BP神经网络片上学习的收敛速度,还提出了学习速率自适应电路.本文采用标准1.2μm CMOS工艺的模型参数,对整个系统进行了sin(x)函数拟合等模拟实验,验证了该片上学习BP神经网络的优越性能.     

An Integrated Temperature Sensor-Controller

The temperature sensor-controller (TSC) and its associated circuit is a multifunctional or systems oriented linear monolithic integrated silicon device. It is designed for low cost (i.e., high yields) and high functional utility. The device has the capability of temperature stabilizing its own environment and that of an associated circuit over a wide temperature range. It can also measure and provide temperature control as well as function as a stable voltage reference. By utilizing several metallization masks the TSC is combined with an operational amplifier, a linear wide range voltage controlled oscillator, an active filter, and other linear circuit functions.     

考虑微磁芯磁阻的分布参数微梁执行器小信号宏模型

以多级弯曲磁微梁执行器为研究对象，先采用梁的模态函数线性组合来逼近梁的变形曲线，然后利用磁路定律，考虑了在宏观磁执行器中忽略的磁芯磁阻，建立了考虑力-磁耦合的非线性方程组，克服了以往的磁微执行器模型不能考虑力磁耦合，而且忽略磁芯磁阻的缺点．计算结果与实验数据及有限元计算结果对比表明，文中的模型有足够的精度，可以作为宏模型使用．     

Theory of nonlinear distortion produced in a semiconductor diode

The extensive literature on the nonlinear behavior of semiconductor devices is reviewed. Over and above what is offered in the literature, the general theory of nonlinear distortion is presented in a clear and easily understood manner. Formulas derive for several of the more important kinds of distortion are readily applicable to any nonlinear transfer characteristic describing frequency-independent impedances. simplified formulas for small-signal levels reveal the relationships between the nonlinear distortions of the same order. For each order, the dependence of the distortions on the operating point of the device is described by a universal fuction. The small-signal approximations are used to investigate the non-linear distortion produced in semiconductor diodes. The universal functions for the Second-, third-, and fourth-order distortions are calculated and graphically presented. Distortion reduction is briefly considered with emphasis on counterphase, modulation. This method substantially reduces the cross modulation in the input circuit of transistor without noticeable loss in amplification.     

Nonlinear design of multiple-cavity switchable dielectric-resonator oscillators

The application of nonlinear CAD techniques to the design of multiple-cavity dielectric-resonator oscillators is demonstrated. The circuit topology consists of an FET oscillator which can be coupled to one of several dielectric resonators by means of a diode switching network. The circuit is numerically designed as a whole making use of a novel broadband optimisation technique especially devised for autonomous nonlinear circuits. At each fundamental frequency of interest the steady state of oscillation is determined by harmonic-balance analysis and at the same time the oscillator is tuned to the prescribed frequency by changing a parameter of the corresponding resonator. The electrical performance is simultaneously specified at all the fundamentals, and the optimisation is carried out with respect to the circuit parameters of the frequency-invariant part of the network.<>     

An accurate model for power DMOSFETs including interelectrodecapacitances

A SPICE-compatible circuit model for power MOSFETs is presented. It is based on device physics and uses a subcircuit representation. The interelectrode capacitances are modeled accurately as nonlinear functions of the applied biases. Various second-order effects relating to the gate capacitance model are discussed, and strategies are presented to include them in the model. The model parameters can be obtained from device measurements. The model is verified by comparing measured and simulated waveforms from a gate charge test circuit     

关于隧道二极管电路

隧道二极管的伏安特性是一条“N”形的曲线，含有隧道二极管的电路是一种非线性电路。研究非线性电路的一种有效方法是分段线性化法,它的特点是把非线性的求解过程分成几个线性区段，对每一个线性区段再应用线性电路的分析方法。本文完整地阐述了分段线性化法的步骤，对如何建立线性化后的方程，进行了较详细的讨论，并在每一个线性区段，建立求解工作点的一组线性方程。最后求解这些方程，它们的有效解就是隧道二极管电路实际的工作点。     

三阶非自治电路中的混沌振荡

本文研究在正弦电源激励下的三阶电路中的非线性动力性质。在该电路中，唯一的非线性元件是分段线性的负电阻元件。计算机模拟和电路实验表明，该电路在电源电压的有效值改变时，振荡制式会有如下之演变：周期—拟周期—混沌—亚超混沌—混沌—周期。此处所谓的亚超混沌振荡，是指相空间轨线的吸引子具有( ，0，0，-)类型的李雅普诺夫指数谱的振荡制式而言的。这种亚超混沌振荡制式在现有的非线性电路与系统的文献中尚不曾有过报道。本文的计算机模拟结果与电路实验结果之间有较好的吻合。     

Soft Fault Feature Extraction in Nonlinear Analog Circuit Fault Diagnosis

Aiming at the problem to diagnose soft faults in nonlinear analog circuits, a novel approach to extract fault features is proposed. The approach is based on the Wigner–Ville distribution (WVD) of the subband Volterra model. First, the subband Volterra kernels of the circuit under test are cleared. Then, the subband Volterra kernels are used to obtain the WVD functions. The fault features are extracted from the WVD functions and taken as input data into the hidden Markov model (HMM). Finally, with classification of features using HMMs, the soft fault diagnosis of the nonlinear analog circuit is achieved. The simulations and experiments show that the method proposed in this paper can extract the fault features effectively and improve the fault diagnosis.     

Linearity performance comparison of cascode current source and single-device current source IDPs; analyses,simulations and measurements

The input differential pair (IDP) is usually a major source of nonlinear distortion in any op-amp. This is especially true if the input signal has a large common-mode component, as is the case when an op-amp functions as a unity-gain buffer or as part of a single-ended sample-hold (S/H) circuit. In this paper, we analyse the distortion of the commonly used cascode current source IDP structure and explain the sources of its nonlinear behaviour. Next, a special design technique is proposed which enhances the linearity of IDPs. The circuit uses a single device current source that has the same channel length while its width is double those of IDP devices. Theoretical analysis, as well as simulation and experimental results, is given to confirm the improved linearity of a unity gain buffer. Simulations predict improvements up to 20 dB. 15 dB total harmonic distortion (THD) reduction was also achieved for a 15 MHz input signal based on measurement of a test chip. The method is valuable as power supply voltages shrink, and the design offers extra voltage headroom at input.     

A LiÉnard Oscillator Resonant Tunnelling Diode-Laser Diode Hybrid Integrated Circuit: Model and Experiment

We report on a hybrid optoelectronic integrated circuit based on a resonant tunnelling diode driving an optical communications laser diode. This circuit can act as a voltage controlled oscillator with optical and electrical outputs. We show that the oscillator operation can be described by LiÉnard's equation, a second order nonlinear differential equation, which is a generalization of the Van der Pol equation. This treatment gives considerable insight into the potential of a monolithic version of the circuit for optical communication functions including clock recovery and chaotic source applications.      

A New Criterion for Nonlinearity of Block Ciphers

For years, the cryptographic community has searched for good nonlinear functions. Bent functions, almost perfect nonlinear functions, and similar constructions have been suggested as a good base for cryptographic applications due to their highly nonlinear nature. In the first part of this paper, we examine using these functions as block ciphers, and present several distinguishers between almost perfect nonlinear permutations and random permutations. In the second part of the paper, we suggest a criterion to measure the effective linearity of a given block cipher. We devise a general distinguisher for block ciphers based on their effective linearity. Finally, we show that for several constructions, our distinguishing attack is better than previously known techniques.     

Perturbation Analysis of Nonlinear Distortion in Analog Integrated Circuits

A method for predicting the distortion in weakly nonlinear analog circuits is presented, which relies on the classical theory of regular perturbation. Accordingly, a nonlinear circuit is described and analyzed as a perturbation of its linearized model, and the response to a periodic signal is analytically calculated through frequency-domain recurrent formulas. The method is simple and quite straightforward to apply, as it involves the calculation of frequency-domain transfer functions and of Fourier coefficients only, making it easily adaptable to any circuit topology. The method can be a valid alternative to the Volterra series method. A relationship between the proposed method and the Volterra series method is established, showing that they lead to very similar approximants to the solution. The method has been numerically tested in practical circuits wherein the devices are modeled by polynomial and exponential nonlinearities.     

Modeling of a constant Voltage transformer

This paper presents a comprehensive nonlinear model of the controlled constant voltage transformer also known as the ferroresonant transformer. Saturation is a normal mode of operation for this device. This paper derives an equivalent electrical circuit that relates to the physical structure of a typical design. The level of detail includes winding resistances, continuously nonlinear magnetizing inductances, tapped windings, and leakage inductances. The paper describes methods to extract the winding resistances, leakage inductances, and hysteresis loops of the transformer and how to fit the latter into single-valued nonlinear functions. The paper compares computer simulation results of the model with those obtained analytically and experimentally. The results show that the derived circuit will be very useful for designers of the ferroresonant transformer, which is used in uninterruptible power supplies.