开关电容网络的灵敏度分析

本文给出了一种有效的开关电容网络计算机辅助灵敏度分析方法。这种新方法利用快速数值型算法获得了符号灵敏度函数。根据该算法编制的计算机程序,可以获得两种灵敏度函数:一种是以增量作为变量的大参量变化灵敏度,另一种是以元件参数本身作为变量的相对灵敏度函数。本文还导出SC网络传输极点及其灵敏度的计算法,最后给出两个计算实例。     

采用一阶运放模型的开关电容电路分析

本文以非零主导极点模型代替开关电容(SC)电路中的非理想运放,得到连续条件下对SC网络拓扑无限制的频率响应式;对矩阵进行行列运算减少了电路变量,避免了复杂计算。这一分析方法已在IBM—PC微型机上实现。文中对二阶带通滤波电路的计算说明了运放有限增益带宽乘积对SC电路性能的影响,以及该分析方法的有效性。     

利用SPICE分析开关电容网络的转换程序——SCNT

本文介绍一个可将双相开关电容网络转换为等效的连续时间电路的计算机程序SCNT。该程序可以接受由单个开关、电容、理想运算放大器、独立电压源和一种多功能SC模块所构成的双相开关电容网络。其输出为直接可被通用电路模拟程序(如SPICE程序)能接受的电路描述。因而,作为一个软件接口,可以利用SPICE方便地分析双相开关电容网络。     

用感性开关电容的正弦波振荡器

正 (一)引言 开关电容(SC)滤波器在1977年被重新提出后,受到了极大的注意。最近,一些作者又利用开关电容方法来实现别的模拟电路,如正弦波振荡器、过零检波器和峰值检波器、跟踪滤波器、锁相环和平衡解调器、压控张弛振荡器,以及模拟延迟线等。 本文描述一种采用感性开关电容的正弦波振荡器。与文献[3]中采用并联开关电容的方案相比,由于感性开关电容在一个时钟周期Tc内,完成两次信息传输,因而预期     

开关电阻对SC放大器速度的影响和优化方法

在开关电容(SC)放大器中,由于MOS开关导通电阻的存在,会对其建立速度产生影响.首先使用跨导运算放大器的一阶线性模型推导了包含开关导通电阻的开关电容放大器的闭环传输函数,通过分析极点和零点的分布,研究了放大器中不同位置开关的导通电阻对阶跃响应的影响.进而提出了一种MOS开关的优化设计方法来缩短放大器阶跃响应的建立时间.最后使用电路仿真工具验证了该方法的有效性.     

使用单位增益缓冲器构成的抗寄生SC跨导

用单位增益缓冲器构成的开关电容滤波器(SCF),若能消除寄生电容引起的阻性寄生,则可用于高频设计,总寄生灵敏度会因此大大降低。本文在此基础上提出一种新的抗寄生开关电容(SC)跨导元件电路差分跨导元件,并用它构成了适用于高频的SC浮地电感和积分器。最后用它实现了一个三阶椭圆函数低通滤波器,并经计算机模拟和实验验证,证明了该方案的正确性。     

SC网络分析的标度-Pauper算法

本文讨论了一种SC网络的频域分析方法,首先探讨了SC网络的标度性质,根据这条性质和特定的Pauper算法,可以用积木块法将SC网络用一个由放大器、电阻和电容组成的连续时间模拟电路来等效.于是,SC网络的频率响应和灵敏度可以调用现有的标准模拟电路分析程序算出,而无须编制专用程序,与已有方法比较,本方法具有计算速度快的优点。     

双线性变换一阶及二阶开关电容电路设计

按双线性变换方法构成的一阶及二阶开关电容电路不但可以用来构成所有各种类型的级联滤波器,而且在按照模拟低通原型滤波器构成的跳耦电路中,用适当的二阶开关电容电路代替积分电路,可将原型滤波器变换为带通或带阻滤波器。文中给出了一阶及二阶开关电容电路的系统设计方法,讨论了各类电路的灵敏度及如何调整电路参数以获得最大输出动态范围。     

一个新的高Q单放大器开关电容滤波器及其最佳设计

本文提出了一个新的高Q单放大器开关电容(SC)滤波器,给出了该电路最大与最小电容比最小的最优设计。同已有文献相比,本文电路的最大与最小电容比已得到大幅度地减小。     

电动汽车锂电池组双层环形均衡器研究

传统Buck-Boost均衡电路传输路径长且均衡效率低,现有的环形均衡器无法从根本上解决该问题。针对该问题,文中提出了一种基于Buck-Boost及开关电容的锂电池双层环形均衡器。该均衡电路采用模块化均衡的方法在底层模块和顶层模块采用Buck-Boost和开关电容的混合电路实现均衡,并采用图论分析的方法,从均衡速度、均衡效率两方面分析电路结构。结果表明,该均衡电路具有能量传输路径少、能量传输效率高的优点。文中在MATLAB/Simulink电力仿真平台上搭建了均衡电路的仿真模型,仿真结果表明基于Buck-Boost及开关电容的双层环形均衡器比单层环形均衡器均衡速度提高了46%。文中搭建了4节电池的实验样机对环形均衡电路工作原理及系统均衡效率进行实验验证,结果表明双层环形均衡器比单层环形均衡器均衡效率可提高26.78%。仿真与实验结果与理论分析一致,说明电路结构合理有效。     

A SWITCHED CAPACITOR CIRCUIT ANALYSIS PROGRAM AND ITS APPLICATIONS

A program developed for analyzing arbitrary N-phase switched capacitor circuits is presented.Application of the program is given.The program simulation facilities,such as time-domain analysis,frequence-domain analysis,sensitivity analysis and multiple ohjective optimization are described.Thealgorithm used in the program is introduced briefly.Several examples are given to show the application of theprogram.     

CAD tools for the synthesis and layout of SC filters and networks

This paper describes two programs for the synthesis and layout generation of SC filters and networks. The first part of the paper describes a technology-independent synthesis and optimization program for SC filters. The program allows for the exact synthesis of cascaded SC biquad and SC ladder filters. Two performance measures related to sensitivity and noise are employed to estimate the performance of the synthesized circuits and to select optimum realizations. The same measures are used in a novel capacitance assignment procedure. The second part of the paper describes a flexible SC layout generator, which can be adapted to various design rules and floorplans by means of a technology file. Area efficient layout is generated by placing individual circuit elements rather than building blocks. Crosstalk between conductors is minimized by a router that distinguishes between different kinds of nodes.1. The scaling of the biquad circuit is dependent on the position of the biquad in the cascade.2. This may not seem to be overly important, since high-pass-type filters do not occur that often in practical applications. If one considers, however, that SCSYN is to be used as a general filter synthesis program, thenevery filter must be automatically realizable. In such an environment, a CAD program that can design all but one type of filter is either quite useless or very limited indeed.3. Note that an SC filter, in contrast to a digital filter, may contain delay-free loops.     

Analog circuit design optimization based on symbolic simulation andsimulated annealing

A methodology for the automatic design optimization of analog integrated circuits is presented. A non-fixed-topology approach is realized by combining the optimization program OPTIMAN with the symbolic simulator ISAAC. After selecting a circuit topology, the user invokes ISAAC to model the circuit. ISAAC generates both exact and simplified analytic expressions, describing the circuit's behavior. The model is then passed to the design optimization program OPTIMAN. This program is based on a generalized formulation of the analog design problem. For the selected topology, the independent design variables are automatically extracted and OPTIMAN sizes all elements to satisfy the performance constraints, thereby optimizing a user-defined design objective. The global optimization method used on the analytic circuit models is simulated annealing. Practical examples show that OPTIMAN quickly designs analog circuits, closely meeting the specifications, and that it is a flexible and reliable design and exploration tool     

用SQP时域优化高速互连线电路

提出了一个基于特征法传输线网络建模和灵敏度分析的非线性高速互连线电路的时域优化设计方法．考虑到高速互连线电路设计的特性,一般其最优值只是在初值的较小邻域,提出用改进的序列二次规划法SQP优化方法保证了算法的整体收敛性及局部超一次收敛性．介绍了用于优化内循环的特征法传输线建模和灵敏度分析．最后,用两个例子证明了方法的可行性．     

用SQP时域优化高速互连线电路

提出了一个基于特征法传输线网络建模和灵敏度分析的非线性高速互连线电路的时域优化设计方法 .考虑到高速互连线电路设计的特性 ,一般其最优值只是在初值的较小邻域 ,提出用改进的序列二次规划法 SQP优化方法保证了算法的整体收敛性及局部超一次收敛性 .介绍了用于优化内循环的特征法传输线建模和灵敏度分析 .最后 ,用两个例子证明了方法的可行性 .     

微波单片模拟电路CAD软件

本文介绍清华电子系正在研制的一部大型微波单片集成电路CAD软件.该软件用于MMIC及MIC模拟电路的分析与优化设计,主要可进行低噪声放大、宽频带放大、功率放大、混频、滤波、天线及匹配网络等电路设计.针对MMIC的特点,采用了多种先进的数值分析方法.在元件分析方面使用了场匹配法、直线法、模型法;电路方面采用元件灵敏度分析、矩量法全电路分析、谐波平衡非线性分析、蒙特卡洛成品率分析;优化技术上利用全域随机优化、梯度优化、灵敏度优化等.经计算与验证,该软件精度高、效果好、使用方便.目前仍在进一步开发研究.     

Two-pole approximation for interconnect design and optimization

Firstly, an approach to find two approximate poles for capturing the system behaviour of interconnect network is presented. Secondly, two parameters, the damping ratio and natural undamped frequency, are expressed as functions of the two poles. These two parameters are used to define an objective function and constraints, which form a constrained multivariable nonlinear optimization problem. The optimization problem is solved using a gradient projection method. One major advantage of our approach is the ability to explicitly control the maximum overshoots at the observation points.     

A New Approach to Reducing Output Ripple in Switched-Capacitor-Based Step-Down DC–DC Converters

Rapidly dropping power supply voltages and tight voltage regulation requirements for integrated circuits challenges power supply designers. A novel interleaved discharging (ID) approach is presented to reduce the output ripple in step-down switched-capacitor (SC) dc-dc converters. Simulation and experimental results of a four-stage SC dc-dc converter show that the ID approach can reduce the output ripple by a factor of three. The proposed approach also improves the converter efficiency by 7%. The ID method provides flexibility in the design optimization of step-down SC dc-dc converters     

DEMON-an optimal seeking computer program for the design of microwave circuits

A program for the design of generalized TEM microwave circuits has been written. The optimization process utilizes a simple but effective rationale called direct pattern search to reduce the error between a desired circuit objective and the current value of a chosen response. Lossy transmission line equations are utilized in the program for exactness. As an example of its utility a 2-4-GHz maximally flat magnitude microwave transistor amplifier is designed and fabricated.