Showing papers on "Spice published in 2003"

An evolutionary approach to automatic synthesis of high-performance analog integrated circuits

Abstract: This paper presents an analog integrated circuit synthesis system based on an evolutionary approach. The system contains several novel features. One of these is the high-performance optimization algorithm, which is a combination of evolutionary strategies and simulated annealing. Modeling of dc parameters is done via a fast dc simulator developed for this purpose whereas modeling of ac parameters can be done either with user-defined equations or with neural-fuzzy performance models trained from SPICE simulations. Another novel feature of the system is the incorporation of matching properties of devices. This way, the optimized circuit becomes tolerant to process variations. The synthesis system has been tested on several independent examples and synthesized circuits have been verified functionally with SPICE simulations. Finally, a prototype chip composed of the three examples has been manufactured. The measurement results have demonstrated the validity of the synthesis system on silicon.

First-Order All-Pass Filter Canonical in the Number of Resistors and Capacitors Employing a Single DDCC

Abstract: In this work, a voltage-mode canonical first-order all-pass filter is presented. The filter contains only a single resistor, a single capacitor, and a single differential difference current conveyor (DDCC). No passive component-matching constraints are required. A complementary metal oxide semiconductor CMOS implementation of a DDCC is given to simulate the proposed circuit with a Spice simulation program whose results illustrate the high performance of the circuit.

Method for producing spice flavor

Abstract: PROBLEM TO BE SOLVED: To establish a method for properly using a synthetic perfume material as a method for preparing a stronger and more natural spice flavor as a systematic means; and to provide the more superior spice flavor by the means. SOLUTION: The spice flavor is obtained by classifying several thousand usable perfume materials by the functional groups to 13 kinds of (A) hydrocarbons, (B) alcohols, (C) phenols, (D) aldehydes, (E) ketones, (F) ethers, (G) esters, (H) carboxylic acids, (I) lactones, (J) furan compounds, (K) furanones, (L) nitrogen-containing/sulfur-containing compounds and (M) natural perfumes, and formulating (1) at least one or more kinds, preferably two or more kinds of materials selected from the groups, with (2) an extract of a spice in a proper proportion. As a result, a desired spice flavor can be easily prepared compared to the conventional method. COPYRIGHT: (C)2005,JPO&NCIPI

Electronically tunable, active only floating inductance simulation

Abstract: In this paper a new floating inductance simulator employing only active elements is proposed. The proposed circuit uses one internally compensated operational amplifier and one dual output current controlled conveyor (CCCII). The simulated inductance value can be controlled electronically by adjusting the bias current of the CCCII. No component matching constraints are imposed for the simulator and all active sensitivities are low. The performance of the circuit is demonstrated on a fourth-order elliptic filter using a SPICE simulation program

A physics based model for the RTD quantum capacitance

Abstract: A simple derivation of the form for the compact model of the quantum capacitance in a resonant tunneling diode (RTD) is presented. The quantum capacitance is shown to reduce the resistive cutoff frequency. The implementation of the model into SPICE is described. The distorting effect of the strongly nonlinear quantum capacitance on an oscillator circuit is demonstrated in a SPICE simulation. The nonlinearity becomes important for the highest frequency applications when the RTD capacitance is comparable to the capacitance in the rest of the circuit.

High-speed digital family using field effect diode

Abstract: Novel high-speed digital subcircuits are proposed using field effect diodes (FED) as active elements. A SPICE simulation of the FED is presented and the characteristics of an inverter are examined. Using FED as the basis for a new digital family is discussed. Simulations show that such circuits are one to two orders of magnitude faster than conventional circuits.

Modeling and optimization of resonant cavity enhanced-separated absorption graded charge multiplication-avalanche photodetector (RCE-SAGCM-APD)

Abstract: In this paper, a physical model of the Resonant Cavity Enhanced-Separated Absorption Graded Charge Multiplication-Avalanche Photodetector (RCE-SAGCM-APD) is presented. First, a SPICE model for RCE-SAGCM-APD is presented showing the dependence of the transfer function of this model on the dimensions, the material parameters and the multiplication gain of the photodetector. The results obtained from this SPICE model are compared with published experimental results and good agreement is obtained. The present SPICE model can also be applied to non RCE-APD and to different versions of avalanche photodetectors by modifying its transfer function. The gain-bandwidth characteristic of RCE-APD is studied for different areas and different values of the thicknesses of both the absorption and the multiplication layers. The gain-bandwidth characteristic of RCE-SAGCM-APD is studied for the case of an inductor added in series to the load resistance and better performance is achieved in comparison to the case with no inductance. The photodetector with and without the inductor is optimized to get the best values of thicknesses of both absorption and multiplication layers and also the optimal values of the series inductance. These optimizations are done for different areas of the photodetector, different multiplication gains and also for different load resistances.

Experimental and simulation studies of single-electron-transistor-based multiple-valued logic

Abstract: Periodic drain current-gate voltage characteristics of single-electron transistors (SETs) were utilized to construct basic components of multiple-valued logic (MVL), such as a universal literal gate and a quantizer. In order to supplement the small gain and the small applicable voltage of the SET, hybrid SET-MOSFET scheme is proposed and demonstrated experimentally using CMOS-compatible pattern-dependent oxidation (PADOX) technology. We also succeeded in reproducing the results using a SPICE circuit simulator with a compact analytical SET model, and estimated the performance of the proposed MVL.

The development of a macro-modeling tool to develop IBIS models

Abstract: A tool to convert SPICE netlists to IBIS (Input/Output Buffer Information Specification) models is presented. This tool simulates the netlist on a user-desirable SPICE engine and produces both static and dynamic characteristics of the IBIS model.

An effective capacitance based driver output model for on-chip RLC interconnects

Abstract: This paper presents a new library compatible approach to gate-level timing characterization in the presence of RLC interconnecting loads. We describe a two-ramp model based on transmission line theory that accurately predicts both the 50% delay and waveform shape (slew rate) at the driver output when inductive effects are significant. The approach does not rely on piecewise linear Thevenin voltage sources. It is compatible with existing library characterization methods and is computationally efficient. Results are compared with SPICE and demonstrate typical errors under 10% for both delay and slew rate.

SPICE modeling of neutron displacement damage and annealing effects in bipolar junction transistors

Abstract: For the purpose of simulating the effects of neutron radiation damage on bipolar circuit performance, we have developed a bipolar junction transistor SPICE model that incorporates displacement damage effects. A physics-based formalism is used for describing the radiation effects within the framework of the Gummel-Poon model. A model structure that includes the dependence of neutron fluence on the relevant SPICE parameters is outlined, from which a simplified radiation model is established. The latter is presented and implemented in AIM-Spice, and it is shown to agree quite well with experiments. Dynamic effects including annealing are also discussed.

Modeling and simulation of a Thermal Management System for Electric Vehicles

Abstract: A Thermal Management System for Electric Vehicles (EV) based on the Peltier-Effect Heat Pumps was designed, fabricated, installed into an EV and its performance was tested. A mathematical model was derived from this system and was simulated using a SPICE program. The results show the applicability of the Peltier-effect heat pumps for the temperature regulation of an EV.

Measurement and SPICE prediction of sub-picosecond clock jitter in A/D converters

Abstract: We propose an innovative characterization technique that allows us to discriminate noise contributions due to jitter from other phenomena (voltage reference and substrate noise, high-amplitude effects) in A-to-D converters. The jitter estimated with this method closely matches that inferred from the signal-to-noise ratio at high input frequencies, where noise is dominated by the aperture uncertainty. At the sub-picosecond level required for the 14-b high-IF ADC under test, any off-chip disturbances substantially affect the accuracy of the measurement. In order to characterize the uncertainty, first the phase noise spectrum of the external clock source is measured and converted into jitter by way of a rigorous formula. Then, the timing ambiguity associated with the on-chip clock pre-amplification and distribution circuitry is simulated via standard Spice techniques, providing results in agreement with experimental evidence. The paper provides tools to isolate the main noise sources in the clock circuit, and optimize it for low jitter in the early simulation phase. Moreover, it arms the designer with a robust yet easy experimental method to assess the jitter value, and interpret the SNR data gathered from test silicon.

Analysis, optimization, and SPICE modeling of resonant cavity enhanced p-i-n photodetector

Abstract: We present a detailed analysis, optimization, and SPICE modeling of the resonant-cavity-enhanced p-i-n photodetector (RCE-p-i-n-PD). Time response, frequency response, and the quality factor of RCE-p-i-n-PD are calculated for different thicknesses of the active layer and for different areas of the photodetector. The standing-wave effect is examined for all these calculations. The effect of the parasitic inductor is studied, and then an optimization is applied to the photodetector to get the optimal value of thickness of the active layer and the series inductor values. Two cases are compared, one with an inductor (L) in series with the load resistor (R/sub L/), and another without this inductor. High performance is obtained in the first case with an inductor, and its optimal values are obtained. A SPICE model for this high-speed photodetector is also presented, and the transfer function of this model is compared for different parameters of the device. Finally, predictions from this SPICE model are compared with published experimental results.

Advanced electro-thermal SPICE modeling of large power IGBTs

Abstract: A novel IGBT electro-thermal model is implemented for the first time in PSpice for the simulation of steady state and transient temperature dependent IGBT operation including self-heating and latchup. A thermal circuit representing the characteristics of the IGBT package is developed and validated against a finite element model and experimental results. A novel electrical IGBT model based on the Kraus model is developed to account for the electrical impact of instantaneous junction temperature variations due to self-heating. The resulting electro-thermal model is validated against experimental dc and transient FBSOA measurements.

Modeling skin effect with reduced decoupled R-L circuits

Abstract: On-chip conductors such as clock and power distribution networks require accurately modeling of the skin effect. Furthermore, to incorporate the skin effect in the existing generic simulation tools such as SPICE, simple frequency independent lumped-element circuit models are needed. A rule-based R-L circuit model is proposed in this paper that predicts the skin effect in the entire frequency range accurately. This circuit model only contains a few parallel branches of resistors and inductors. A maximum error in impedance values of less than 3% is achieved using only two or three constant element branches.

A new physics based SPICE model for NPT IGBTs

Abstract: A physics based, non-punch-through, insulated gate bipolar transistor (NPT-IGBT) model is presented, as well as its porting into available circuit simulator SPICE. Developed model results in a system of ODEs, from which time/space hole/electron distribution is obtained, and is based on solution of ambipolar diffusion equation (ADE) through a variational formulation, with one-dimensional simplex finite elements. Model implementation, in a circuit simulator, is made by means of an electrical analogy with the resulting system of ODEs. Other parts of the devices are modeled using standard methods. Thus, this new hybrid model combines advantages of numerical and mathematical methods, through modeling charge carrier behavior with high accuracy even maintaining low execution times.

SPICE model libraries for via transitions

Abstract: A procedure of building SPICE models for signal via transitions between printed circuit board layers is presented in this paper. The method of extracting parameters of SPICE models from full-wave simulation tool is demonstrated. Then the validity of SPICE models is studied by comparing the solution from SPICE model with that from the full-wave simulation.

SPICE modelling of PCRAM devices

Abstract: Approaches to producing SPICE models for phase-change RAM devices are discussed Alternative models based around the lumped parameter approach, which vary in complexity, are compared Consequently the PSpice models for the PCRAM are presented and evaluated for the steady state mode of the device operation

Computer Simulation of Responses of Earth-return Circuits to the AC and DC External Excitation

Abstract: The use of the circuit simulation package SPICE (Simulation Program with Integrated Circuit Emphasis) permits the complex analysis of the EMI (electromagnetic interference) on earth-return circuits. In the approach presented, the earth-return circuit with excitation by AC signals and transients, as well as with DC energization is modelled as a large multinode electrical equivalent circuit. The circuit is a chain of basic circuits, which are equivalents of homogenous sections of the earth-return circuit with uniform exposure to the primary interfering electric field associated with the inductive and the conductive influence. The application of controlled voltage and current sources in the basic circuits permit the modelling of coupling effects in systems of earth-return circuits. Contrary to the analytical methods the SPICE simulation enables one to solve the EMI problems in practical cases connected with: topological complexity of the system considered, non-homogeneous geometrical and electrical parameters of the earth-return circuits, non-homogeneous earth, application of insulating flanges, bonds, earth electrodes in a system of earth-return circuits, non-linearity of the system, etc. The SPICE simulation is an alternative and a useful approach to the analysis of EMI problems in earth-return circuits, when comparing with existing analytical and numerical solutions. The usefulness of the SPICE simulation has been illustrated by examples.

Effects of parasitic electrical components on an ultrasound system: measurements and simulations using SPICE models

Abstract: When driver and receiver electronics for an ultrasound measurement system are physically implemented, parasitic components are introduced in the system. These may arise from bond wires, circuit board paths or cabling. The parasitic components will influence the excitation pulse behavior as well as amplitude and time of arrival for received pulses. In the system investigated, a coaxial cable is used to connect the transducer with the electronics. The inductance and capacitance of the cable are dominating parasitic components in the system. This paper investigates the effects of these components for varying cable lengths and compares measurements with system simulations using SPICE models. The simulations give highly accurate temporal behavior of the excitation pulse. The peak to peak amplitude and the perceived time of flight of the received echo in a pulse echo system is measured. Amplitude variations of 60% are recorded for cable lengths varied between 0.07 m and 2.3 m., with simulations predicting the same variations. The time of flight is measured using the excitation pulse as time trigger. Variations are up to 40 ns for a total travel time of about 8 μs. The simulations predict this variation within a few ns.

P‐71: OLED Pixel Design Employing a Novel Current Scaling Scheme

Abstract: A new active matrix organic light emitting diode (AMOLED) pixel design is proposed by employing a novel current scaling scheme and verified by SPICE simulation. The new pixel design scales down the data current more effectively to guarantee less charging time, compared with conventional current mirror structure, as well as compensates the variation of the electrical characteristics of poly-Si TFTs, such as threshold voltage and mobility.

A new linearization technique for a CMOS differential amplifier using bulk-driven weak inversion MOS transistors

Abstract: A new CMOS differential amplifier using MOS transistors in weak inversion is presented. Because of the exponential characteristic of a MOS transistor in the subthreshold region, an original linearization technique based on a parallel connection of two differential stages opposite excited and different polarized is implemented. The canceling of the third-order term from the output voltage expression allows obtaining a reduction of the distortion coefficient with about an order of magnitude. The current consumption of the circuit is very small due to the subthreshold operation of transistors, making it compatible with low-power designs. The SPICE simulation confirms the theoretical estimated linearity improvement.

The electrothermal macromodel of the monolithic voltage regulator LT1073 for SPICE

Abstract: In this paper the problem of modelling selfheating influence on the characteristics of monolithic switch-mode power supplies is considered The LT1073 integrated circuit (IC) has been chosen for detailed investigations Its new ElectroThermal Macromodel (ETM) joining the Electrical Model (EM) along with the thermally dependent parameters and the Lumped Thermal Model (LTM) generating the junction (inner) temperature of LT1073 is proposed The correctness and usefulness of the new model has been revealed by means of comparison of measurements and simulations of BOOST converter including LT1073 device

A New Physics Based SPICE Sub-circuit Model for Insulated Gate Bipolar Transistors (IGBTs)

Abstract: A physics based, Non-Punch-Through, Insulated Gate Bipolar Transistor (NPT-IGBT) model is presented, as well as its porting into available circuit simulator SPICE. The developed model results in a system of ODEs, from which time/space hole/electron distribution is obtained, and is based on solution of ambipolar diffusion equation (ADE) trough a variational formulation, with posterior implementation using one-dimensional simplex finite elements. Other parts of the device are modeled using standard methods. Thus, this new hybrid model combines either advantages of numerical methods or mathematical, through modeling charge carrier behavior with high accuracy even maintaining low execution times. Implementation of the model in a general circuit simulator is made by means of an electrical analogy with the resulting system of ODEs.

Simulation of ion sensitive transistors using a SPICE compatible model

Abstract: The goal of this paper is to present a SPICE compatible electro-chemical model of the ion sensitive field effect transistor (ISFET). The presented approach is not entirely new and constitutes certain improvement of earlier works, e.g. by Grattarola et al. The main novelty of the model consists in the introduction of variable carrier mobility and the application of a more advanced model of the electrolyte double layer. These improvements allowed more accurate simulation of the device operating with different hydrogen ion concentrations and in different temperatures.