Artículos

Computing Symbolic Expressions in Analog Circuits Using Nullors

Cálculo de Expresiones Simbólicas en Circuitos Analógicos usando Anuladores

Esteban Tlelo Cuautle^1,2, Carlos Sánchez López¹ and Federico Sandoval Ibarra³

1 INAOE, Department of Electronics,
Luis Enrique Erro No. 1, Tonantzintla, Puebla. 72000 México.
Tel/Fax: +52–222–2470517
e.tlelo@ieee.org, csanchez@inaoep.mx
http://www.inaoep.mx

2 Instituto Tecnológico de Puebla

3 CINVESTAV, Guadalajara Unit,
sandoval@cts–design.com

Article received on July 14, 2003; accepted en July 08, 2005

Abstract

A novel method is introduced to compute symbolic expressions in analog circuits modeled by nullors. The proposed method is based on the formulation of a compact system of equations (CSEs) by manipulation of data–structures, which highly improves traditional symbolic–methods. It is demonstrated that by modeling all active devices using nullors, the CSEs is easily formulated by manipulation of both the nullor and admittance interconnection–relationships. Several examples leads us to conclude on the suitability of the proposed symbolic–method to be incorporated within a symbolic simulator.

Keywords: Symbolic analysis, Modeling and simulation, Circuit theory, Data structures, Nullor.

Resumen

Se presenta un nuevo método para calcular expresiones simbólicas en circuitos analógicos modelados con anuladores (nullors). El método propuesto se basa en la formulación de un sistema de ecuaciones compacto (SEC), a través de la manipulación de estructuras de datos, lo cual mejora notablemente los métodos simbólicos tradicionales. Se demuestra que modelando todos los dispositivos activos usando nullors, el SEC se formula fácilmente por manipulación de las relaciones de interconexión del nullor y admitancias. Algunos ejemplos conducen a concluir en la confiabilidad del método simbólico propuesto para incorporarlo dentro de un simulador simbólico.

Palabras Clave: Análisis simbólico, Modelado y simulación, Teoría de circuitos, Estructura de datos, Anulador.

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Acknowledgment

This work was supported in part by CONACyT/MEXICO under project number 40321, and CoSNET/MEXICO under project number 454.03p.

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