Interactive compact device modelling using Qucs equation‐defined devices

Abstract

SUMMARYRecent trends in compact device modelling and circuit simulation suggest a growing movement towards standardization of Verilog-A as a vehicle for semiconductor device specification and model interchange among commercial and open source simulators. This paper introduces a nonlinear equation-defined device (EDD) characterized by current, voltage and charge equations with a similar syntax to Verilog-A. The EDD has been implemented in Qucs and used extensively as a central feature in an interactive modelling system that allows straightforward prototyping of compact device models prior to translation into Verilog-A. To illustrate the properties and the use of the Qucs EDD a number of examples centred on well-known SPICE models are described.

A tabular source approach to modelling and simulating device and circuit noise in the time domain

“…Resistor Rx and capacitor Cx act as a low-pass filter that ensures the value of the current used to calculate shot noise is purely dc and does not contain any time varying components. Shot noise is computed during simulation by Qucs non-linear equation-defined device EDD D2 [14]. The graph plotted in Figure 3(c) presents a set of shot noise results obtained from simulation of the shot noise subcircuit model over the dc current range 1 mA to 1 A.…”

Qucs Frequency Domain Non-Linear Compact Modelling and Simulation of IC Spiral Inductors On Silicon

“…SPICE 3f5 cannot directly handle linear or non-linear behavioural device models whose properties are entirely or partially characterised by a physical effect that is a function of AC signal frequency. With the recent improvements in General Public License (GPL) circuit simulators this situation is changing, particularly through the introduction of Frequency Dependent Equation-Defined Device (FEDD) models [3], non-linear current/voltage static and dynamic Equation-Defined Device (EDD) models [4] and user controlled swept signal frequency simulation employing Harmonic Balance steady state analysis. The Quite Universal Circuit Simulator (Qucs) [5] is a package that implements a number of important frequency dependent extensions.…”

Improvements in Qucs-S equation-defined modelling of semiconductor devices and IC's

“…Defined Device (EDD) modelling of existing and emerging technology devices and IC's has become an established technique since the Qucs EDD was first released roughly ten years ago [1] [2]. The popularity of the Qucs EDD component can be largely traced back to three of its primary characteristics; firstly it can model the static and dynamic properties of physical devices expressed as a set of explicit compact model equations, secondly the structure and properties of the Qucs EDD have a direct relationship to Verilog-A hardware device language (HDL) statements [3], making conversion of EDD models to Verilog-A straight forward [4], and finally EDD model technology is both interactive and integrates easily with conventional circuit simulation components.…”