2025 ASEE Annual Conference & Exposition

Integrating Full-Featured and Freely-Downloadable Circuit Simulation Software into Multiple EET Courses

This paper will present the integration of LTspice, a full-featured and freely-downloadable circuit simulation software, into multiple EET courses, including electric circuits, analog and digital electronics, power electronics, signals and systems, signal processing, control systems and communication systems. The software is driven by a powerful SPICE engine, and has schematic capture and waveform viewing capabilities. Its behavioral voltage and current sources in combination with dependent sources make the integration of mathematical and system-level work, in addition to traditional circuit-level simulation work, highly attractive for EET and related curriculums. Additionally, application of mathematics (differentiation and integration, differential equations, and Laplace and Fourier transforms) for analysis, modeling, design, and simulation of engineering systems can be easily implemented within the LTspice environment. System-level design concepts such as user-defined components and devices, subcircuits, hierarchical circuits, and worst-case performance analysis can be part of the simulation experience as well.

Integrating the use of a free and powerful circuit simulation software in multiple courses bodes well for both face-to-face and online/remote modes of instruction. Additionally, the first two of the five student outcomes criteria specified by ABET-ETAC can be easily addressed and assessed within the simulation environment. The program criteria related to the application of mathematics to characterize electrical/electronic systems can be satisfied within the same simulation environment as well. However, it is natural to ask why emphasize LTspice over other commonly used SPICE based circuit simulation software such as PSpice and NI Multisim. The main reason is that LTspice is a full-featured software yet freely downloadable. Moreover, the advantage of integrating a single simulation software into multiple EET courses, the focus of this paper, is independent of the specific package selected. A major advantage of using LTspice is that it is free to students and faculty in the truest sense; i.e., no licensing expiration issues, and no limitations in terms of number of components and/or circuit nodes. There is also no limitation on the types of simulation that can be run (dc operating point, transient, ac analysis, dc sweep, small signal transfer function, and noise analysis). Numerous SPICE directives are available to exploit the many features of this software, including parametric analysis, temperature analysis, Fourier analysis, and Monte Carlo analysis.

The full paper will provide numerous examples of circuits and systems design, modeling, and simulation using LTspice. Specific examples will cover various disciplinary areas within EET type curriculums such as circuit analysis, analog and digital electronics, energy and power systems, power electronics, signals and systems, Laplace and Fourier transforms, signal processing, control systems and communication systems. Additionally, examples of mathematical analysis using differential and integral calculus and differential equations within the simulation environment will be included. The full paper will also address ABET-ETAC student outcomes and associated assessment instruments, as applied to computer simulation-based coursework.