On the implementation of general four-terminal DC device models in SPICE

The circuit-simulator program SPICE has been used worldwide by industry and academia to simulate wide varieties of IC designs. With the advance of technology have come many new devices that cannot be simulated by SPICE in its current form. We present methods for implementing classes of new DC device models directly into the source code of SPICE. The techniques described are illustrated for the case of the El-Mansy MOSFET model.     

DC characteristic simulation for floating gate neuron MOS circuits

An original approach to DC characteristic SPICE simulation for floating gate neuron MOS circuits is demonstrated. A novel macromodel which calculates the floating gate potential by combining resistances and dependent voltage and current sources is introduced. Utilising this method, DC characteristics for neuron MOS circuits have been confirmed to be successfully simulated using SPICE     

Extraction of high-frequency equivalent circuit parameters ofsubmicron gate-length MOSFET's

As the effective gate-length of a MOSFET reduces, its high-frequency characteristics improve. However, they become more difficult to model. Current SPICE models are based on DC measurement data and simplistic capacitance models which can only approximate the high-frequency device characteristics up to a fraction of the device unity current gain frequency (f_τ). Thus, it is important to investigate the high-frequency characteristics and then incorporate the small-signal equivalent circuit parameters in SPICE. In this, work we report a simple nonquasi static model, which offers good accuracy needed for circuit simulation, and a new curve fitting method for the extraction of the network model elements. The current work is part of a study aimed at improving the existing scalable model for MOSFET's, and it focuses on extracting the elements of an equivalent circuit which describes the state-of-the-art device     

Simulation of optically injection-locked microwave oscillatorsusing a novel SPICE model

Optical injection-locking of GaAs field-effect transistor microwave oscillators has been examined experimentally as well as by using two different optical interaction models. An additional simulation program with IC emphasis (SPICE) circuit for observing small locking ranges is also described. This first-order interaction model which utilizes a standard version of SPICE produces predictions of injection-locking range in excellent agreement with measured results. These tools allow the oscillator designer to optimize the injection-locking performance by analyzing various circuit topologies and DC bias levels     

Equivalent circuit approach for single electron transistor modelfor efficient circuit simulation by SPICE

A new compact DC/transient single electron transistor model for circuit simulation by SPICE is introduced. This model includes newly developed equivalent circuit approach based on the time-dependent master equation and an exact conductance or transient conductance model. The simulation speed of this model is improved compared with that of the previous models     

低温ECL电路的直流特性分析

本文在对低温双极晶体管的直流特性的分析基础上,推导出ECL电路在低温下的直流解析模型,并与实验结果和计算机模拟结果进行了比较,还对SPICEⅡ模型在低温下的修正和低温ECL电路的设计进行了一些探讨。     

SPICE implementation of lossy transmission line and Schottky diodemodels

The author describes models for the lossy transmission line and the Schottky diode that are incorporated into the source code of the circuit simulation program SPICE (version 2G.6). The model used for the lossy transmission line was derived by A.J. Gruodis (1979). The DC model for the Schottky barrier diode as shown was formulated by D.B. Estreich (1983). Examples used to verify the models are given     

ANALYSIS OF DC CHARACTERISTICS OF ECL CIRCUIT AT LOW TEMPERATURE

Based on the analysis of DC characteristics of silicon bipolar transistors at low temperature, DC analytic models of ECL circuit at low temperature are derived, then compared with the experimental data and computer simulation results. The modification of SPICE BJT model about temperature and design of low temperature ECL circuit are discussed.     

An Investigation of the Charge Conservation Problem for MOSFET Circuit Simulation

MOSFET capacitor models implemented in circuit simulators currently do not guarantee charge conservation, which is extremely crucial for the simulation of dynamic RAM's, switched capacitor filters, and other MOS VLSI circuits. Several MOSFET capacitor models have been introduced in the literature; however, none of these models addresses the actual reasons of charge nonconservation in SPICE2. This charge conservation problem has been studied and the causes are found. Our investigations show that charge is the appropriate state variable, and that the nonconservation of charge in SPICE2 stems from a numerical integration problem quite independent of the device physics. A new charge model has been derived, implemented in SPICE2, and tested. The new model differs from the previous models in two respects. First, it uses both charge equations and capacitance equations. Second, the partitioning of the channel charge between the source and drain terminals is carried out by requiring the charge equations to satisfy self-consistent boundary conditions. A strong emphasis is placed on charge continuity, both in the conventional operating region and in the region of weak inversion and accumulation. Benchmark tests indicate that this new model conserves charge while reducing the simulation time by 18-85 percent compared to Meyer's model which was originally used in SPICE2.     

适合器件设计和电路模拟的SiGe基区HBT物理模型

提出了一个模拟ＳｉＧｅ基区ＨＢＴ器件特性的物理模型。在基区部分考虑了发射结处的价带不连续、大注入效应、Ｇｅ组份变化及重掺杂效应引起的能带变化的影响；在集电区分析时考虑了基区推出效应、载流子速度饱和效应、电流引起的空间电荷区效应以及准饱和效应。在此基础上给出了ＳｉＧｅ基区ＨＢＴ器件的电流和电荷公式。同时开发了ＳｉＧｅ基区ＨＢＴ的直流瞬态模型和小信号模型。利用修改的ＳＰＩＣＥ程序模拟了实际ＳｉＧｅ基区     

Modified Gummel-Poon model for susceptibility prediction

This paper describes a new model of the bipolar transistor by which the effects of RF interference on the DC quiescent operating point upset can be computed. It is an improvement of the Gummel-Poon (GP) model used in circuit simulators like SPICE in the sense that it takes into account distributed phenomena excited by RF interference like the DC and AC crowding of the emitter current in the base region. The model, implemented in SPICE, has been experimentally validated and its efficiency has been demonstrated. The model does not require more measurements then those necessary to extract the parameters of the conventional GP model     

Advanced SPICE-Modeling of 4H-SiC MESFETs

A modified drain source current suitable for simulation program with integrated circuit emphasis （SPICE） simulations of SiC MESFETS is presented in this paper. Accurate modeling of SiC MESFET is achieved by introducing three parameters in Triquint＇s own model （TOM）. The model, which is single piece and continuously differentiable, is verified by measured direct current （DC） I-V curves and scattering parameters （up to 20 GHz）.     

Drain current model for undoped Gate Stack Double Gate (GSDG) MOSFETs including the hot-carrier degradation effects

In this paper, analytical models of drain current and small signal parameters for undoped symmetric Gate Stack Double Gate (GSDG) MOSFETs including the interfacial hot-carrier degradation effects are presented. The models are used to study the device behavior with the interfacial traps densities. The proposed model has been implemented in the SPICE circuit simulator and the capabilities of the model have been explored by circuit simulation example. The developed approaches are verified and validated by the good agreement found with the 2D numerical simulations for wide range of device parameters and bias conditions. GSDG MOSFET design and the accurate proposed model can alleviate the critical problem and further improve the immunity of hot-carrier effects of DG MOSFET-based circuits after hot-carrier damage.     

器件与电路参数对SET波形影响仿真研究

利用Sentaurus TCAD仿真软件,建立并校准了MOSFET仿真模型。分析了NMOS器件在重离子轰击下产生的SET波形。结果表明,轰击位置在漏极且入射角呈120°时,器件具有最大的峰值电流。通过建立MIX、TCAD、SPICE三种反相器模型并施加重离子轰击,研究了不同模拟方式下电路响应对SET波形的影响,指出了采用双指数电流源在SPICE电路中模拟的不准确性。采用MIX模型探究了器件结构及电路环境对SET波形的影响。结果表明,LET能量、栅极长度、轨电压和负载电容都会对SET波形脉宽及平台电流大小产生显著影响,说明了建立SET模拟波形时须综合考虑这些因素。     

VDMOS等效电路的SPICE模型

分析了VDMOS器件中存在的各种寄生效应以及这些寄生效应对器件性能的影响,在此基础上建立了VDMOS等效电路的SPICE模型.通过MEDICI数值分析软件,模拟VDMOS在不同偏置条件下的电压、电流、电容特性,从而提取出VDMOS等效电路模型参数.并用SPICE软件对等效电路仿真,进行了直流分析和瞬态分析,得到等效电路的电学特性曲线图.仿真的结果与MEDICI器件模拟工具模拟结果相互比较,具有较好的一致性.     

Two-dimensional simulation of conducted currents characteristics inelectrical discharges

In this paper, a simple general electrical discharges circuit model for electrical discharge current waveform simulation in overvoltaged air gaps is presented. A macroscopic circuital method of simulation utilizing the standard SPICE network simulator, based on a two-dimensional (2-D) nonlinear impedances network has been proposed. The structure of the simulation framework is designed to take into account the electrode geometries in a straightforward way. A study of conducted current waveform for different electrode geometries has been done. Experimental data have been used to validate the simulation results     

Transit-time model for short-channel MOSFET's

A new analytical transit-time model for submicrometer MOS devices has been developed. The model is based on a modified SPICE level-three MOSFET DC model, and it allows the use of a physical value for the charge carrier saturation velocity. This is essential for accurate transit-time modeling. Both DC and transit-time models show good agreement with the results obtained from more complicated two-dimensional numerical simulations     

RTD的器件模型和模拟——共振隧穿器件讲座(9)

阐述了电路模拟在设计和研制大规模集成过程中的必要性和重要意义,器件模型在电路模拟中的重要性以及器件模拟与器件模型的关系;在器件模拟通用软件形成过程的基础上重点讨论了RTD的器件模型、器件模拟和电路模拟软件SPICE三个课题;介绍了基于物理参数I-V方程RTD模型和高斯函数、指数函数RTD直流模型;利用ATLAS器件模拟通用软件对RTD进行了器件模拟,得到了势垒和势阱宽度、E区掺杂浓度等对RTDI-V特性的影响;以包含RTD电路的SPICE电路模拟中的文字逻辑门为例,通过电路模拟验证了其逻辑功能,对设计该电路起到指导和参考作用。     

GaAs数字单片电路的计算机模拟

本文在开发并确立通用电路分析程序SPICE3A7的GaAs MESFET模型及相应模型参数提取方法的基础上,对GaAs MESFET器件及相关BFL.单元电路进行了直流和瞬态的计算机模拟和部分优化,取得了较好结果;并对研制中的分频器电路设计进行了计算机研究.