H+离子敏场效应传感器的SPICE模型仿真分析

本文从离子敏场效应晶体管(ISFET)的传感机理出发,利用计算机辅助设计软件(SPICE)建立了ISFET的物理模型。借助此模型,对器件的电学行为进行了模拟,仿真结果与实验数据取得了良好的一致性。     

3‐D simulation of compound thin‐film transistors

Abstract— A 3‐D technology CAD (TCAD) tool for the numeric modeling of thin‐film compound transistors is described. The model takes into account the influence of different bulk doping levels due to the non‐stochiometric film composition as well as the influence of donor and acceptor boundary traps. Apart from the field effect, the temperature dependence of the thin‐film transistor (TFT) is also calculated. The TCAD tool successfully explains the behavior of thin CdSe TFTs and shows that the off‐current is determined by the grain‐boundary traps.     

基于SPICE二次开发的电路仿真软件的设计

提出了一种利用SPICE作为行为仿真模型来设计电路仿真软件的新颖方法,通过对SPICE在源码基础上的改造和扩充,将其作为仿真内核,并以COM组件的形式集成于多媒体虚拟环境中,成功解决了仿真技术与多媒体技术的融合设计问题,构建了一种智能电路仿真系统.测试结果与推广应用情况表明,系统具有良好的可设计性、操作的任意性和具有真实感的交互功能,使用户能像操作真实实验一样来操作,从而达到良好的实验效果.     

OpenMP Implementation of SPICE3 Circuit Simulator

In this paper, we describe our experience of creating an OpenMP implementation of the SPICE3 circuit simulator program. Given the irregular patterns of access to dynamic data structures in the SPICE code, a parallelization using current standard OpenMP directives is impossible without major rewriting of the original program. The aim of this work is to present a case study showing the development of a shared memory parallel code with minimum effort. We present two implementations, one with minimal code modification and one without modification to the original SPICE3 program using Intel’s taskq construct. We also discuss the results of the case study in terms of what future compiler tools may be needed to help OpenMP application developers with similar porting goals. Our experiments using SPICE3, based on SRAM model simulation, were compiled by the SUN compiler running on a SunFire V880 UltraSPARC-III 750 MHz and by the Intel icc compiler running on both an IBM Itanium with four CPUs and Intel Xeon of two processors machines. The results are promising.     

Enabling a compact model to simulate the RF behavior of MOSFETs in SPICE

A detailed methodology for implementing a MOSFET model valid to perform RF simulations is described in this article. Since the SPICE‐like simulation programs are used as a standard tool for integrated circuit (IC) design, the resulting model is oriented for its application under the SPICE environment. The core of the proposed model is the popular BSIM3v3, but in this model the RF effects are taken into account by means of extrinsic lumped elements. Good agreement between the simulated and measured small‐signal S‐parameter data is achieved for a 0.18‐μm channel‐length MOSFET, thus validating the proposed model. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE 15, 2005.     

Relating the SPICE framework and SEI approach to software process assessment

In June 1993, an international effort (SPICE) was launched to develop a standard for software process assessment. An important goal of this effort is to harmonize existing process assessment approaches. This paper describes and characterizes SEI and SPICE software process assessment work and then highlights the similamties and differences. The following aspects are considered-underlying philosophy, goals, scope/domain, rating processes, underlying reference model, tailorability and impact on the international software community.     

基于UML的模拟电路仿真系统的设计*

模拟电路仿真程序对集成电路设计和电路性能评价具有十分重要的意义。近年来,面向对象技术已成为软件设计的主流思想,以电路仿真系统为背景,给出了一种基于UML的面向对象的分析与设计方法,清楚有效地进行系统建模。这种方法在模拟电路仿真系统SPICE的开发过程中被证明是提高软件开发质量和效率的有效途径。     

用TCAD进行IC新工艺的开发

文章对集成电路工艺计算机辅助设计系统(TCAD虚拟FAB系统)做了简要介绍,指出了TCAD在新工艺开发中的地位,提出了利用TCAD进行新工艺开发的思想。以synopsys公司的TWB虚拟FAB系统为例,对TCAD用于新工艺的开发作了探讨,并给出了以此为平台进行700V高压BCD工艺设计的实例。     

Charge density and bare surface barrier height in GaN/AlGaN/GaN heterostructures: A modeling and simulation study

In this article, we present a physics‐based model to explain the effect of the GaN cap layers on the 2D electron gas density and the bare surface barrier height in AlGaN/GaN heterostructures. We consider that the 2DEG originates from the surface donor states present on the GaN cap top surface. The influence of a 2D hole gas, formed when the valence band crosses the Fermi energy level, has also been considered. This model agrees well with the published experimental results and TCAD simulations, and can easily be incorporated into the modeling of GaN/AlGaN/GaN‐based HEMT devices.     

Single-electron tunneling depressing synapse for cellular neural networks

In this paper, a cellular neural network with depressing synapses for contrast-invariant pattern classification and synchrony detection is presented, starting from the impulse model of the single-electron tunneling junction. The results of the impulse model and the network are simulated using simulation program with integrated circuit emphasis (SPICE). It is demonstrated that depressing synapses should be an important candidate of robust systems since they exhibit a rapid depression of excitatory postsynaptic potentials for successive presynaptic spikes.     

A system-level model for a silicon thermal flow sensor

A system-level model with lumped parameters for a thermal flow sensor is presented. The model is built with 13 circuit cells consisting of thermal resistors and thermal capacitors in SPICE. The circuit cell originates from the heat conduction equation using the Finite Differential Method, including the 2-D thermal conduction cell, the convection cell, and the thermal capacity in the chip. Based on the thermal model of the flow sensor, the 2-D temperature distribution of the chip can be calculated with SPICE in both the constant power mode (CP) and constant temperature difference mode (CTD). As an example, the system level model of the thermal anemometer in the CTD mode was established in PSPICE. Wind tunnel test was carried out to verify the system model, and show a reasonable agreement with the simulation results, with an error less than 8%.     

用于光电讯号检测的有源滤波器的计算机辅助设计

本文介绍了有源滤波器的计算机辅助设计。采用了ＳＰＩＣＥ程序进行仿真。运算放大器采用由无源元件和受控源组成的线性模式。利用计算机仿真，不仅可以知道频域响应，而且可以知道时域响应。实验值和仿真值有良好的符合。     

基于RLC模型的互连线时延估算

对VLSI电路中RLC互连线的时延进行了研究,使用改进的一阶模型来近似分布式均匀传输线的传输函数,计算出时域下的阶跃响应并得到简洁的时延计算公式.然后将其应用到具体的RLC互连树中计算源节点到漏节点的时延,其驱动器模型由电阻和电容组成,负载为容性负载.实验结果表明,该模型的计算结果与SPICE仿真结果的误差小于10%,计算量也比基于二阶传输函数的算法大为减少,在计算效率和精度两方面得到较好折衷,可以用于考虑时延效应的优化程序中.     

Nonlinear SPICE models for physiologic systems

Most biological systems are nonlinear but investigators interested in modeling them often make linear approximations to avoid performing tedious manual calculations. SPICE (Simulation Program with Integrated Circuit Emphasis, developed at the University of California, Berkeley, CA), an electrical circuit simulation program, is frequently used for creating and analyzing linear network models of physiologic and pathophysiologic processes. However, few investigators use the full capabilities of the program by modeling nonlinear elements. We developed six nonlinear SPICE elements, allowing simplified modeling of most commonly encountered physiologic processes. These are provided as subcircuits that can be easily incorporated into existing SPICE models. Included are voltage and current controlled nonlinear resistors, capacitors and inductors. In addition, we describe adders, multipliers, powers, inverse, and derivative functions.     

Simulation of the coupling of the external electromagnetic field to PCB traces in the SPICE simulator

In this article, a simple method of modeling and simulating electromagnetic field coupling to PCB in the SPICE simulator is presented. The method exploits two assumptions: quasi-TEM wave propagation along PCB traces and representation of an external electromagnetic noise by a plane wave. Under these assumptions, a model of electromagnetic field coupling to the PCB traces is created in the form of an active n-wire transmission line placed in an inhomogeneous (that is, three layers) medium. Next, using the method of successive approximations, an equivalent active n-port (described by means of scattering parameters) is found. This work results in formulas that express the external electromagnetic field in the form of current sources and the way they are simulated in SPICE. The method is illustrated with two examples. © 2004 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14, 190–200, 2004.     

基于模型修正技术的模拟集成电路几何规划优化方法

为了兼顾模拟集成电路设计优化的求解精度和计算效率,提出一种基于正项式模型修正技术的几何规划优化方法.首先将模拟集成电路的设计目标与约束简化为正项式模型,然后在采用几何规划方法迭代优化的过程中利用晶体管级SPICE仿真不断修正这一正项式模型.实例表明,与传统基于公式的优化方法和基于仿真的优化方法相比,该方法能够在尽量保证计算效率和全局最优解的前提下使优化精度满足晶体管级SPICE仿真的要求.     

Characterization and modeling of metal-film microbolometer

The characteristic thermal parameters of a platinum-film microbolometer are extracted from the data of two measuring methods. A simple and accurate equivalent circuit model, along with its thermal behavior, is proposed for the device. Applying the model to simulate some device circuits results in good agreement with the experimental data. Furthermore, an effective method of ambient temperature compensation, proposed previously by our laboratory, is demonstrated both experimentally and by simulation using the same model. The established electro-thermal model therefore serves as an useful tool for SPICE simulations in the design of microbolometers     

非线性电路分析系统的设计及仿真研究

针对MATLAB在解析高阶非线性电路时存在的困难以及与当前主流电路系统分析软件的不兼容性,设计了基于MATLAB平台并兼容SPICE规范的电路分析系统.研究的主要内容有:使用离散化伴随模型降维方法得到非线性器件的直接与递归线性化仿真模型,用四象限法进行非线性电路的直流计算,对时域线性多步数值积分方法的初值、步长和断点进行了优化设计.结果表明:系统保证了电路的仿真精度,大大加快了仿真速度,且降低了对工作平台的要求,弥补了 MATLAB平台在高阶非线性电路仿真方面的不足.     

SPICE-compatible microwave model of an optically controlled high electron mobility transistor

The effect of optical illumination on the microwave characteristics of an optically gated AlGaAs/GaAs HEMT has been studied theoretically. This article describes an integral approach to the problem which includes the calculation of the capacitance and the sheet concentration of the two-dimensional (2D) electron gas in the illuminated condition. The changes in the various intrinsic parameters of the device under the illuminated condition have been utilized to calculate the Y-parameters of the device at microwave frequencies. The lumped circuit model of the device in the illuminated condition has been obtained with the various components determined from the Y-parameters. The attractive feature of the present model is that it is fully compatible with commonly used circuit simulation packages like SPICE. © 1996 John Wiley & Sons, Inc.     

Average power control and positioning of polysilicon thermal actuators

This paper reports on characterizing and modeling the behavior of micromachined polysilicon thermal actuators when driven by DC or pulsed drive signals. Thermal actuators can be controlled and positioned using a pulsed input with a period much less than the thermal time constant of the device as demonstrated by data collected in air and vacuum. Both pulse width and pulse amplitude modulation were successfully employed to position lateral actuators, lateral actuator arrays, and piston micro-mirrors. A SPICE model for polysilicon thermal actuators was developed using relationships between resistance, deflection, and average power. This model incorporates the polysilicon thermal actuator's electrical load, transient response, and deflection characteristics necessary for predicting actuator performance and developing microsystems. The SPICE model exhibits very close agreement with the measured performance of the polysilicon thermal actuators.