An Interactive Website as a Tool for CAD of Power Circuits
Bartlomiej Swiercz, Lukasz Starzak, Mariusz Zubert, Andrzej Napieralski
Department of Microelectronics and Computer Science, Technical University of Lodz, PL
Keywords: CAD, SPICE, power electronic circuits, distributed device modeling, web-based simulation, behavioral modeling and simulation
The rapid development of microelectronics results in more complex semiconductor device structures and makes it necessary to use modern computer software. However, high prices and hardware requirements considerably limit the access to these CAD tools from the part of educational institutions, students or small enterprises, and free software usually lacks for well implemented numerical algorithms and device models. In order to overcome these limitations and to make accurate and modern semiconductor device models widely accessible a website has been designed, allowing internet users to perform interactive simulations of circuits comprising distributed model of power diode (http://www.dmcs.p.lodz./dmcs-spice).
The designed software has been based on Berkeley SPICE core because of popularity and well established position of this circuit simulator. The CAD package runs in Linux environment and has been developed using Open Source and GNU-licensed software. It comprises four main modules (Fig. 1): an user-side graphical interface (web browser), dynamically visualizing the generated HTML code; a resource providing software (Apache server with PHP code interpreter); a batch-executed simulator based on the Berkeley SPICE3f5 core and including the device models developed by the authors; the graphical post-processor GNUPlot. Thanks to the proposed solution, simulation and data processing may be performed on dedicated servers, thus not engaging the end-users’ computers; moreover, no additional software has to be installed on the end-user side.
Due to their specific structures, the power devices need special models different from those developed for low power electronics. Traditional models implemented in commonly used circuit simulators are becoming not sufficient for design of power integrated circuits working with realistic load. For this sake a distributed 1D model of power diode has been developed and included in the presented CAD package (Fig. 2). In this model, the carrier concentration distribution in the lightly doped wide base is calculated using data saved at the previous time point. This allows for obtaining more accurate and realistic results than using standard SPICE diode models (Fig. 3).
The presented simulation software gives the internet community the possibility to simulate realistic behavior of a power diode, with only a web browser needed. Because of client-server software architecture and free code used makes it easy to use the package in distance learning and facilitates further development of the presented tool in cooperation with other scientific centers throughout the world and with the interested internet community. In the future, it is considered to include new models of power devices, to implement behavioral description languages as well as multi-domain distributed models.
NSTI Nanotech 2003 Conference Technical Program Abstract