Showing papers on "Spice published in 1995"

Modeling and analysis of multichip module power supply planes

Abstract: A method that would allow accurate modeling of arbitrarily shaped planes with bypass capacitors has been developed. It is compatible with a SPICE-based modeling method for the rest of the power supply hierarchy and the devices. A modified SPICE is used to accommodate distributed circuits. The distributed circuits are built with microwave analysis software and connected to SPICE by s-parameter files. The modeling process is described and examples of thick and thin-film power supply planes are presented with comparison to measured results. The method is used to explore potential design choices for a large MCM with many simultaneously switching drivers. >

An LCL resonant converter with PWM control-analysis, simulation, and implementation

Abstract: A three element resonant converter capable of driving a voltage type load with load independent operation is analyzed using a state-space approach. Pulse width modulation is employed to control and regulate the output voltage. Closed-form solutions are obtained under steady state conditions. The experimental study of a prototype converter reveals complete agreement with the analytical and SPICE simulation results. Typical experimental oscillograms are given to verify the basic principles. >

Interconnect characterization using time-domain reflectometry

Abstract: An approach is presented for modeling board-level, package-level, and multichip module substrate-level interconnect circuitry based on measured time-domain reflectrometry data. The scattering poles and residues of a multiport system are extracted and used as a model that can be evaluated in linear time by recursive convolution in a SPICE-based simulator. This allows any linear or nonlinear circuits to be connected to the model ports, and the entire circuit may be simulated in in a SPICE-based simulator. Two-port and four-port example microstrip circuits are characterized, and the simulation results are compared with measured data. Delay, reflection, transmission, and crosstalk are shown to be accurately modeled in each case. >

SPICE: Practical Device Modeling

Abstract: Practical device modelling modelling capacitors, inductors and resistors modelling rectifier and zener diodes modelling bipolar and Darlington transistors modelling small signal MOSFETs and JFETs modelling power MOSFETs modelling analogue behavioural elements.

Signal isolation in BiCMOS mixed mode integrated circuits

Abstract: Comparing several cross-talk reduction schemes using two-dimensional device simulation and measurements on silicon has shown that while SOI based processes provide high isolation from cross-talk, fully junction isolated wells can provide equal or better cross-talk immunity at a lesser expense. Simple guard ring substrate contacts appear to be the technique best suited for preventing cross-talk at high operating frequencies. A lumped parameter equivalent circuit has also been developed to simulate fully junction isolated wells in SPICE.

IGBT SPICE model

Abstract: During the last few years, great progress in the development of new power semiconductor devices has been made. The new generation of power semiconductors is capable of conducting more current and blocking higher voltage. The IGBT (insulated gate bipolar transistor) is an outgrowth of power MOSFET technology. More like a MOSFET than a bipolar transistor in structure, the IGBT has some of the electrical characteristics of both. Like a MOSFET, the gate of the IGBT is isolated, and drive power is very low. The on-state conduction voltage of an IGBT is similar to that of a bipolar transistor. However, SPICE users are constantly faced with the inability to analyze circuits that contain devices that are not in the SPICE library of the semiconductor models. With the authors' own computer program, a complete macromodel of the IGBT for the SPICE simulator has been computed. In this paper, a complete IGBT SPICE macromodel is described and verified with experimental results. >

SPICE Models for Vacuum-Tube Amplifiers

Abstract: PSpice analog behavioral models for the vacuum-tube triode and pentode are given. The application of these models to the computer analysis of audio power amplifiers is described. An example SPICE simulation of a vacuum-tube amplifier is presented

Dynamic SPICE-simulation of the electrothermal behavior of SOI MOSFET's

Abstract: A nonlinear dynamic electrothermal model of the SOI MOSFET is implemented and used in SPICE3. This model is formulated as a set of algebraic and (partial) differential equations which is converted into a SPICE3 netlist automatically by a model translator. Neither is the simulator rewritten nor are SPICE device models implemented or changed. In this way, the presented approach supports effective model development. To show the electrothermal interaction, the SOI MOSFET model is applied to several static and dynamic simulations. The SPICE-simulation results of the thermal model are verified with the commercial finite-element simulator ANSYS. >

An algorithm for identifying unstable operating points using SPICE

Abstract: The standard SPICE dc operating point analysis does not distinguish between stable and unstable operating points. Circuit designers can be misled when an operating point "looks" correct on the basis of dc simulation but turns out to be unobservable once the circuit is breadboarded or fabricated. The algorithm presented herein can identify a large class of unstable operating points, and it has been incorporated into the SPICE dc operating point analysis without compromising analysis speed. >

SPICE simulation of surface acoustic wave interdigital transducers

Abstract: Surface Acoustic Wave (SAW) devices, are not normally amenable to simulation through circuit simulators. In this letter, an electrical macromodel of Mason's Equivalent Circuit for an interdigital transducer (IDT) is proposed which is compatible to a widely used general purpose circuit simulator SPICE endowed with the capability to handle negative capacitances and inductances. Illustrations have been given to demonstrate the simplicity of ascertaining the frequency and time domain characteristics of IDT and amenability to simulate the IDT along with other external circuit elements. >

A physics-based HBT SPICE model for large-signal applications

Abstract: A new, physics-based, large-signal SPICE model for graded-base HBT's is reported. The novelty of the model lies in its use of the emitter-base diode ideality factor to account for the voltage dependencies of the tunneling factor and the barrier height for back injection of electrons. This expedient allows the HBT to be simply represented in SPICE by the regular homojunction BJT macromodule of this stimulator. The usefulness and accuracy of the model are demonstrated by comparisons of simulated and measured data for a graded-base AlGaAs-GaAs HBT: DC I-V data and large-signal switching results from a ring-oscillator circuit are presented. >

An extended Tanh law MOSFET model for high temperature circuit simulation

Abstract: The Tanh law MOSFET model proposed earlier by Shousha & Aboulwafa (see ibid., vol. 28, no. 2, p. 176-9, 1993) is extended to predict the temperature dependence of the drain current by including the temperature dependence of the threshold voltage and the mobility. The model requires fewer temperature dependent parameters compared to SPICE level2 model. The extended model shows good agreement between measurement and simulation of devices with different device geometries over wide temperature range (27-200/spl deg/C). >

Realistic worst-case SPICE file extraction using BSIM3

Abstract: In this paper, a methodology for generating worst-case SPICE files is presented. This methodology is based upon the identification and evaluation of circuit building blocks within a design. Correlations between these block are determined for a specific circuit variable. The results show there is a high degree of correlation between NAND, NOR, inverter logic gates and NAND gates implemented in Complementary Pass Transistor Logic (CPL) with regards to speed and power dissipation. A method of resolving multiple SPICE files is also presented which produces a realistic prediction of circuit performance.

SPICE-models for high-pincount board connectors

Abstract: We present results obtained from a reliable SPICE model for SIPAC connectors. By means of typical measurement and simulation results, the reliability of the simulation model is demonstrated. All important electric characteristics of the connectors can be simulated by the SPICE-model, e.g., different time delays and characteristic impedances, transmission, and reflection characteristics and near-end and far-end crosstalk. There are no restrictions in the simulation concerning pin assignments. The comparison between simulation and measurement is very good up to a limit of f=3 GHz and a risetime of t/sub r/>35 ps.

Energy recovery for low-power CMOS

Abstract: Energy recovery, as a means to trade off power dissipation for performance in CMOS logic circuits, is analyzed and investigated. A mathematical model is presented to estimate the efficiency for two energy-recovery approaches under varying conditions of voltage swing, transition time, and MOS device parameters. This model can be directly compared to the well-known model for supply-voltage scaling, which is the prevalent method for trading power dissipation for performance. The two models are evaluated against SPICE simulations. Excluding body effects, which would not be present in CMOS process technologies such as Silicon-On-Insulator (SOI), the simulations and the equations agree to within 10%. The simulations also indicate that energy recovery, when implemented with circuit techniques such as bootstrapping, can significantly outperform the supply-voltage-scaled approach across a wide range of operating frequencies. To further investigate this result, two eight-bit adder designs, one based on supply-voltage scaling and the other on energy recovery, are simulated and compared.

Study of carrier transport effects on quantum well lasers using a SPICE simulator

Abstract: The effects of carrier transport time across a separate confinement heterostructure on the characteristics of quantum well (QW) lasers are investigated through the equivalent circuit model derived from Nagarajan's rate equations. Turn-on delay and frequency modulation of QW lasers are obtained using a SPICE simulator. It is shown that turn-on delay is linearly proportional to the transport time corresponding to the cladding layer thickness under high prebias conditions. The modulation bandwidth and peak magnitude both decrease while the transport time increases.

A SPICE model for IGBTs

Abstract: Berkeley SPICE is the most popular program for simulating the behavior of electronic circuits. The biggest stumbling block that most engineers run into is turning company specifications or vendor data sheets into SPICE device models that emulate real devices and run without problems. This is especially true for power devices, like IGBTs, where the cost of testing and possibly destroying devices is prohibitive. This paper describes the first known SPICE subcircuit macro model for IGBTs. Simulation results and a simple software solution for extracting SPICE models from data sheet parameters are presented. >

Full-swing high speed CBiCMOS digital circuit for low-voltage applications

Abstract: A new complementary BiCMOS circuit to achieve full-swing and high speed for low-voltage applications is presented. The proposed circuit utilises the parasitic lateral bipolar transistor, generic to the CMOS process, to speed up the pull-down transient performance. It is based on the submicron technologies and specifically designed, simulated, and comparatively evaluated for low supply voltages. The analysis, simulations and SPICE results are used, not only to confirm the functionality of the circuit but also to compare its performance in terms of speed, output voltage swing, power dissipation, and cascading (chain) effect. Experimental results have been obtained to evaluate the BiFET action in a BiCMOS low voltage environment. >

Piecewise-linear modeling of I-V characteristics with SPICE

Abstract: This paper presents a technique for piecewise-linear modeling of arbitrary nonlinear I-V characteristics with SPICE. In particular, I-V characteristics (including those exhibiting negative resistance) that lend themselves to piecewise-linear approximation are easily modeled using six elemental building blocks; three for voltage-controlled I-V characteristics and three for current-controlled I-V characteristics. The elemental building blocks are implemented with resistor, diode, independent voltage source, and independent current source SPICE primitives. Two of the elemental building blocks use the ability of SPICE to accept negative values for the resistance and diode saturation current parameters. The technique is applied to model a unijunction transistor and a tunnel diode. Two negative resistance oscillator examples which use these models are included; a current-controlled negative resistance sinusoidal oscillator (unijunction transistor) and a voltage-controlled negative resistance relaxation oscillator (tunnel diode). These examples have been used to teach the fundamentals of negative resistance oscillators and nonlinear effects to sophomores and juniors. >

CMOS high-frequency rectifier with unity voltage gain

Abstract: A new CMOS voltage rectifier circuit based on the current mode technique is presented. The circuit exhibits highly linear characteristics over a wide range of input values. It is extremely simple and compact, and a very effective building block for VLSI analogue IC design. SPICE simulated results are given, in good agreement with theoretical results.

SPICE analysis of signal propagation in Si microstrip detectors

Abstract: The main DC and AC characteristics of AC-coupled polysilicon-biased silicon microstrip detectors have been measured in order to determine the set of SPICE parameters of these devices based on a RC network. For this purpose each strip has been divided in 200 unit cells and simulations with 5 and 9 strips have been performed. The model is capable of calculating the interstrip and coupling impedance and phase angle in good agreement with experimental results up to a frequency of 1 MHz. The electrical propagation of a current signal simulating the charge pulse of a ionising particle along the strips has been studied. The role of the input characteristics of the read-out electronics on the detector output signals has been addressed. The signal propagation has been studied also for anomalous working conditions of the detector, such as a strip with a break in the Al film, or disconnected from the read-out electronics. >

Eddy current modeling of silicon steel for use on SPICE

Abstract: The relation between the equivalent eddy current field He and the instantaneous flux density rate dB/dt is experimentally obtained for current transformers made of silicon steel. The results show that He is proportional to (dB/dt)/sup 0.6-0.7/ in the operating frequency range (/spl sim/100 Hz) of the current transformers. The ac B-H loop calculated by combining the proposed eddy current model with the Jiles-Atherton model agrees well with the measured data. In addition, this combined model allows magnetic component characteristics using SPICE to be simulated. The simulated secondary voltage waveforms of current transformers are in satisfactory agreement with the measured values.

Calculating distortion levels in sampled-data circuits using SPICE

Abstract: This paper presents an analysis technique that can be used to compute the harmonic and intermodulation distortion levels of a sampled-data circuit directly from a SPICE transient analysis. It is useful for analyzing the nonlinear behavior of switched-capacitor and switched-current circuits at the transistor level. The approach is valid for all input signal levels, makes no assumption of the underlying nonlinearity, and its accuracy is limited only by the numerical accuracy of SPICE.

A close loop DC motor speed control simulation system using SPICE

Abstract: This paper presents a complete close loop DC motor speed control system model in SPICE. The results are validated comparing them with the data produced by a testing system.

Photovoltaic system simulation using a standard electronic circuit simulator

Abstract: An approach to photovoltaic (PV) system simulation is presented based on the use of SPICE instead of using a specifically developed software package. SPICE models for PV cells, PV modules, lead-acid batteries and the rest of the main components of a PV system have been developed. A simulation example of a stand-alone PV system including measured irradiance data as an input is used to show some of the possibilities inherent in such an approach. Greater flexibility, quick access to all voltages and currents within the system and a simpler way of interfacing with standard electronic components are the main conclusions to be drawn from this work.

Neutral base recombination in advanced SiGe HBTs and its impact on the temperature characteristics of precision analog circuits

Abstract: We present the first comprehensive investigation of neutral base recombination (NBR) in advanced UHV/CVD SiGe HBTs, and quantitatively assess its impact on the temperature characteristics of precision analog circuits. We show that a direct consequence of NBR in SiGe HBT's is the degradation of Early voltage (V/sub A/) when transistors are operated with constant current input (forced-I/sub B/). We quantitatively address the impact of NBR on precision SiGe analog circuits by incorporating the effect into a new version of SPICE, calibrating the SPICE models to data, and simulating different types of precision current sources across the temperature range of -55/spl deg/C to 85/spl deg/C.

Using Spice and behavioral synthesis tools to optimize ASICs' peak power consumption

Abstract: This paper describes a methodology that combines Spice simulations with a behavioral synthesis tool to estimate and optimize digital ASICs' peak power consumption. Spice can be used to provide very accurate and complete measures of power consumption. A behavioral-level tool is then used to minimize the use of power in each clock cycle by carefully selecting the appropriate hardware, while simultaneously scheduling operations. Results show substantial reductions in peak power.

Microelectromechanical gyroscope: analysis and simulation using SPICE electronic simulator

Abstract: Microgyroscope applications are increasing in many fields, creating a need to develop low cost, compact gyroscopes. A full understanding of the operation principles and limitations of a rate gyroscope are essential in creating a small and low-cost device. Currently, there is no simulation tool available that can simulate both the electronic and nonelectronic components of a complete device. The work described in this paper presents a method to simulate a complete comb-drive rate microgyroscope using the SPICE electronic simulation tool. The simulation method given here can be generalized to a wide range of MEMS devices. An equivalent circuit was developed and simulated using SPICE. Results of the frequency response, and transient analysis are given. The results obtained reproduce the reported device operation. A set of important new findings are revealed from the analysis using this new tool. Using the transient analysis, for example, we can see that the requirement of a large quality factor of the sensor causes a very slow (open-loop) response and that a closed-loop operation is essential in this device. In addition, the nonideal factors are described and are analyzed using SPICE.

A MOS analog-switch macromodel for charge injection analysis

Abstract: This paper presents a SPICE macromodel, which allows the accurate prediction of charge injection from single-channel MOS analog switches. The macromodel is based on a closed-form solution to the system of differential equations that describe a typical sample-and-hold circuit. Experimental results, applying the developed model are discussed.