Showing papers on "Spice published in 1984"

A Complete GaAs MESFET Computer Model for SPICE (Short Papers)

Abstract: A model for the gallium arsenide MESFET has been implemented into the source code of the well-known circuit simulation program SPICE. Both large-signal and small-signal simulations of MESFET circuits are now possible within the familiar framework and data format of SPICE. The line-by-line modifications made to SPICE to achieve the model implementation will be made available to interested researchers.

A Three Port Model for Thickness Mode Transducers Using SPICE II

Abstract: A model based on Schwarz's artificial transmission line (ATL) model [l] has been developed for use on the SPICE I1 circuit analysis program. The model uses lumped elements configured as two stages. The first stage models the electrical behavior of the transducer. The second stage consists of a T type artiticial transmission line which models the acoustic behavior of the transducer. Piezoelectric coupling is modeled by dependent circuit sources in each stage. Expressions are derived for the minimum number of artificial transmission line sections as a function of maximum tolerable error in Zo, phase error, and cut off frequency. Comparison of simulation results with actual transducer systems show agreement. simulation of the complete transducer system: transducer, driver and receiver electronics, plus electrical and acoustical matching and acoustic loading. The model is extremely easy to use allowing

A sensitivity analysis of SPICE parameters using an eleven-stage ring oscillator

Abstract: SPICE is a circuit simulator which predicts node voltages and currents as a function of time from device model parameters. Model parameters are determined by the manufacturing process, but process-induced variations in these parameters occur within a chip or from chip to chip. Values for the model parameters used in simulators are usually obtained from measurements on test structures along the periphery of the circuit or in test chips located at several sites on the product wafer. This paper presents examples of how well model parameters extracted from a test chip can predict the AC response of a dynamic circuit element (MOS ring oscillator) on the same wafer. Simulation results show which model parameters are critical to performance. A comparison between measurement and simulation results is given and the importance of intrachip and intrawafer parameter variations is discussed. For the samples tested, the polysilicon gate linewidth variation was determined to be the primary cause of the ring oscillator frequency variation.

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

Abstract: 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.

Potential Power Performances of the Distributed Amplifiers

Abstract: In this paper experimental and theoretical results are presented These results show that the distributed amplifiers can be used not only for small signal operations but also for high power applications with a very broad-band frequency The results are verified by comparing an analytical model predicted with measurements between 3 to 12 GHz The simulation uses SPICE 2 program Finally, in this paper, we show the feasability of the distributed amplifier for power applications

A sensitivity analysis of SPICE parameters using an eleven-stage ring oscillator

Abstract: SPICE is a circuit simulator which predicts node voltages and currents as a function of time from device model parameters. Model parameters are determined by the manufacturing process. Process-induced variations in these parameters occur within a chip or from chip to chip and cause corresponding variations in circuit performance. Values for the model parameters used in simulators are usually obtained from measurements on test structures which are found along the periphery of the circuit or in test chips located at several sites on the product wafer. Because of the spatial separation between test structures and the circuits of interest, differences between measured and simulated performance can occur. This paper presents examples of how well model parameters extracted from a test chip can predict the ac response of a dynamic circuit element (ring oscillator) on the same wafer. Simulation results show which model parameters are critical to performance. A comparison between measurement and simulation results is given and the importance of intra-chip and intra-wafer parameter variations is discussed. For the samples tested, the polysilicon gate linewidth variation was determined to be the primary cause of the ring oscillator frequency variation.

SPICE source code implementation of aDC model for the non pinchoff depletion mode MOSFET

Abstract: The implementation of the Lin model for the non pinchoff depletion mode MOSFETs directly into the source code of the SPICE 2G.5 circuit simulation program is described. The computational advantages of our implementation over Lin's subcircuit approach are pointed out, and, more significantly, certain previously undiscovered limitations of both methods are discussed. The encoding of the model into SPICE is described in sufficient detail so as to be duplicable by other interested researchers. Our results compare favorably to experiment and to the more comprehensive El-Mansy model. Finally, a new method of parameter extraction is described for the El-Mansy model, which makes it possible to derive the parameters of the Lin and El-Mansy models simultaneously.

Using SPICE for the modelization of the static behaviour of the insulated gate transistor

Abstract: A new application of a circuit simulation program (SPICE) is presented. The static behaviour of a complex bipolar device (COMFET or IGT) is analysed from an equivalent circuit including the physical components of the real device. It is possible to infer about technological parameters to improve the working of the IGT Une nouvelle application d'un programme de simulation de circuits (SPICE) est presentee ci-dessous. Le comportement statique d'un composant bipolaire complexe (IGT) est analyse a partir d'un circuit equivalent faisant apparaitre les parametres physiques du dispositif reel. Cette analyse permet de modifier les parametres technologiques afin d'ameliorer le fonctionnement du transistor a grille isolee