SRAM circuit-failure modeling and reliability simulation with SPICE

Based on some new accelerated lifetime models and failure equivalent circuit modeling techniques for the common semiconductor wear out mechanisms, simulation program with integrated circuit emphasis (SPICE) can be used to characterize CMOS VLSI circuit failure behaviors and perform reliability simulation. This paper used a simple SRAM circuit as an example to demonstrate how to apply SPICE to circuit reliability modeling, simulation, analysis, and design. The SRAM circuit, implemented with a commercial 0.25-/spl mu/m technology, consists of functional blocks of 1-bit six-transistor cell, precharge, read/write control, and sense amplifier. The SRAM operation sequence of "write 0, read 0, write 1, read 1" was first simulated in SPICE to obtain the terminal voltage and current stress profiles of each transistor. Then, normalized lifetimes of all transistors in terms of each failure mechanism were calculated with the corresponding accelerated lifetime models. These lifetime values were sorted to single out the most damaged transistors. Finally, the selected transistors were substituted with failure equivalent circuit models, and SPICE simulations were performed again to characterize the circuit performance, functionality, and failure behaviors. The simulation shows that the 0.25-/spl mu/m technology, hot-carrier injection (HCI), and time-dependent dielectric breakdown (TDDB) had significant effects on SRAM-cell stability and voltage-transfer characteristics, while negative bias temperature instability (NBTI) mainly degraded the cell transition speed when the cell state flipped. This illustrative SRAM simulation work proves that, with SPICE and the failure equivalent circuit models, circuit designers can better understand the damage effects of HCI/TDDB/NBTI on the circuit operation, quickly estimate the circuit lifetime, make appropriate performance/reliability tradeoffs, and formulate practical design guidelines to improve the circuit reliability.     

Modeling and simulation of an electronically commutatedpermanent-magnet machine drive system using SPICE

This paper describes the design of high-efficiency, electronically commutated, permanent-magnet machine (ECPM) drives based on the finite-element/difference method, and the solution of the ensuing differential equations with the Simulation Program with Integrated Circuit Emphasis (SPICE). The permanent-magnet motor model includes the computation of load-dependent components of the motor-equivalent circuit (e.g., induced voltages and inductances). A new SPICE metal-oxide semiconductor field-effect transistor (MOSFET) model reflecting the reverse-recovery current phenomenon-which is very important for the design of variable-speed drives operating in the pulse-width-modulated (PWM) mode-is introduced. Results of this new model are compared with measurements. Since ECPMs lend themselves well to vehicle propulsion due to their inherent high efficiencies at light weight, it is desirable to have a very high output-power-to-weight ratio for such applications. In addition, high ECPM drive efficiencies are important for recovery of the braking energy     

Applications of SPICE simulation software to the study of reliability and availability in electrical engineering education

The effectiveness of SPICE in calculating probabilities, reliability, steady-state availability, and mean time to failure of repairable systems described by Markov models is demonstrated. Two examples are presented. The first example is a two-unit, warm standby, microcomputer system with self-reset function and repair facility. The second example is a robotic system comprising two identical robots and one safety system. In both cases, the results obtained using SPICE are compared with previously published results obtained using the Laplace transform method. Full SPICE listings are included.     

Novel non‐linear macromodel suitable for SPICE simulation of analogue multipliers realized with bipolar and CMOS technologies

The purpose of this paper is to propose a simple and accurate non‐linear macromodel for analogue multipliers. The performance of the new macromodel is demonstrated by comparing the SPICE simulation results obtained with the device‐based models and with the macromodel. The most important result obtained in the frame of this work is the combination of accurate modelling with reduced computer time, thus providing the IC designer with the possibility of speeding up the simulation of large electronic systems. Copyright © 1999 John Wiley & Sons, Ltd.     

Application of digital computers to the study of power systems with asynchronized electromechanical frequency converters

The advent of large scale computers with high computational speeds enables more complex systems with interconnected subsystems to be studied and implemented     

Real-time digital simulation of power electronics systems with Neutral Point Piloted multilevel inverter using FPGA

Most of actual real time simulation platforms have practically about ten microseconds as minimum calculation time step, mainly due to computation limits such as processing speed, architecture adequacy and modeling complexities. Therefore, simulation of fast switching converters’ instantaneous models requires smaller computing time step. The approach presented in this paper proposes an answer to such limited modeling accuracies and computational bandwidth of the currently available digital simulators.As an example, the authors present a low cost, flexible and high performance FPGA-based real-time digital simulator for a complete complex power system with Neutral Point Piloted (NPP) three-level inverter. The proposed real-time simulator can model accurately and efficiently the complete power system, reducing costs, physical space and avoiding any damage to the actual equipment in the case of any dysfunction of the digital controller prototype. The converter model is computed at a small fixed time step as low as 100 ns. Such a computation time step allows high precision account of the gating signals and thus avoids averaging methods and event compensations. Moreover, a novel high performance model of the NPP three-level inverter has also been proposed for FPGA implementation. The proposed FPGA-based simulator models the environment of the NPP converter: the dc link, the RLE load and the digital controller and gating signals. FPGA-based real time simulation results are presented and compared with offline results obtained using PLECS software. They validate the efficiency and accuracy of the modeling for the proposed high performance FPGA-based real-time simulation approach. This paper also introduces new potential FPGA-based applications such as low cost real time simulator for power systems by developing a library of flexible and portable models for power converters, electrical machines and drives.     

Fuzzy理论在电力系统铁磁谐振研究中的应用

根据电力系统铁磁谐振的模糊性,应用Fuzzy理论对电力系统发生铁磁谐振的可能性、影响因素及防止措施进行了研究.这种新方法对补充和完善铁磁谐振问题的研究具有重要的意义.     

Fuzzy理论在电力系统铁磁谐振研究中的应用

根据电力系统铁磁谐振的模糊性 ,应用Fuzzy理论对电力系统发生铁磁谐振的可能性、影响因素及防止措施进行了研究。这种新方法对补充和完善铁磁谐振问题的研究具有重要的意义     

Digital simulation of electrical systems to reinforce laboratoryteaching

For the purpose of reinforcing undergraduate laboratory teaching, we have shown some applications of PSpice in the simulation of communication and control systems. Examples discussed include the telephone link, the quadrature PSK system, a feedback control system with transport lag and nonlinearity, and a digital control system. In each example, a schematic diagram of the system, the input circuit file, and representative output graphs are given. With behavioral modeling of some devices in the system, the simulation time for each job is kept to within a few minutes. As a result, students are able to run such programs using the evaluation version of the package on their personal computers     

基于蒙特卡罗仿真和非线性规划技术的输电系统充裕度评估

采用非序贯Monte Carlo仿真法抽取输电系统的故障状态,并采用连接矩阵存储和广度优先搜索技术实现网络拓扑分析,从而高效解决了多重故障识别和孤岛处理问题,并节省了状态抽取的时间.同时建立了最优负荷削减非线性规划模型,用非线性原对偶内点法求解.利用故障状态抽样概率和最优负荷削减量加权的方法对严重故障状态进行筛选和排序,找出系统运行风险和薄弱环节.IEEE-RTS实例的评估结果证明了所提算法的正确性和有效性.     

Proteus与第三方IDE联合搭建单片机系统仿真平台

在实际单片机系统开发过程中,利用Proteus软件对设计系统进行仿真,已经成为一种主流趋势,针对Proteus自带编译器的不足,采用Proteus与第三方IDE联合搭建单片机系统仿真平台,易于提高开发效率。通过一个具体单片机系统实例,引入了两种常用的第三方IDE软件,与Proteus联合搭建仿真平台,取得了满意的仿真效果。     

铁电存储器在单片机数据采集系统中的应用

本文结合PIC16F877A单片机采集系统,采用二线制12C串行总线方式,给出铁电存储器FM24C64与PIC16F877A单片机的硬件接口电路图,简化线路板的空间。而且,还介绍了关于铁电存储器FM24C64的基本时序,读写过程,及其软件设计的步骤。这种设计方案节省功耗、成本,克服了EEPROM或者其他非易失性存储器的不足,提高了采集系统工作稳定,陛和可靠性,可以广泛的用于PIC单片机产品的开发和研制。     

Hypothetical simulation of non‐linear systems with memory,using an ideal computer with infinite speed and capacity

The solution of equations describing non‐linear dynamic systems is considered. A computer with infinite speed and capacity—as a hypothetical device—is assumed. The method is based on the classical sampling theorem, Newton iteration and discrete Fourier transform. Algorithms for transient and periodic cases, working simultaneously in the time and frequency domain are introduced and demonstrated. Copyright © 2000 John Wiley & Sons, Ltd.     

单片机控制在网板烘干线上的应用研究

在对网板烘干机PLC控制电路及其功能分析的基础上,通过研究得出一套完整的单片机控制电路,其功能可以完全替代烘干机PLC,并且在硬件和软件上,采用光藕和滤波及引导指令抗干扰设计大大提升了电路的稳定性,使整台机器运行可靠。     

Reliability assessment of restructured power systems using reliability network equivalent and pseudo-sequential simulation techniques

This paper presents a technique to evaluate reliability of a restructured power system with a bilateral market. The proposed technique is based on the combination of the reliability network equivalent and pseudo-sequential simulation approaches. The reliability network equivalent techniques have been implemented in the Monte Carlo simulation procedure to reduce the computational burden of the analysis. Pseudo-sequential simulation has been used to increase the computational efficiency of the non-sequential simulation method and to model the chronological aspects of market trading and system operation. Multi-state Markov models for generation and transmission systems are proposed and implemented in the simulation. A new load shedding scheme is proposed during generation inadequacy and network congestion to minimize the load curtailment. The IEEE reliability test system (RTS) is used to illustrate the technique.     

SDH和WDM光纤技术的应用与对比分析

随着科技的进步,带动了现代电力通信技术的蓬勃发展.光纤通信已经逐步成为了电力系统通信的主要方式.首先介绍了SDH技术和WDM技术的基本概念以及各自在电力系统通信中的应用,然后对各自的优势和缺陷进行了对比分析.通过分析发现,对于不同的场合和应用,应该选择合适的技术去匹配,同时还应该充分考虑将几种技术综合起来应用以发挥优势...     

Optimization of linear systems for 3D parallel simulation of semiconductor devices: Application to statistical studies

The 3D simulators are nowadays essential in semiconductor device modelling in order to study fluctuation effects when devices are scaled to gate lengths approaching nanometre dimensions. To take into account these effects it is necessary to perform statistical studies, which have a high computational cost. The resolution of the linear systems generated by the discretization of partial differential equations is the most time‐consuming part of the simulation process. In this paper we propose an optimization of the linear system solution procedure based on domain decomposition methods implemented in a 3D parallel drift–diffusion device simulator. We have also carried out an analysis of the parallel performance of the device simulator. Numerical results show superlinear efficiency values up to 62 processors in the solution of the Poisson equation. The results were obtained on a Cluster HP Integrity Superdome. Copyright © 2008 John Wiley & Sons, Ltd.     

单片机I^2C总线与数字电位器通信的Proteus仿真

针对传统单片机系统开发方法存在硬件调试困难,研究了基于EDA软件Proteus的仿真平台,实现单片机系统的仿真。对单片机I^2C总线原理进行了分析,设计了基于8051单片机的I^2C总线与数字电位器AD5242数据通信系统。仿真结果表明,该总线数据通信系统的设计方案是可行的,具有一定的实际使用价值。     

联合仿真反事故演习系统应用与研究

做好调度人员的技术培训是保证电网安全的首要任务之一,阐述了华东电网调度员联合仿真反事故演习系统的设计要点,该系统将DTS和OTS两大原来独立运行的培训系统运用数据网络通信技术有机结合构成,并对实现的关键技术进行了详细说明,运行实践表明系统特别适合大区域多站反事故演习。