PLMAP — A piecewise linear MOS circuit analysis program

A few techniques based on an efficient use of memory resources, called matrix caches, to speed up the transient analysis of piecewise linear circuits such as power electronic circuits are presented. These techniques use the fact that the matrix in the linear equation solving routines can only have a finite number of different values. Hence, by adding a cache memory management technique to store the LU factor of these matrices for future reuse, the linear equation solver can be performed much faster than that of a general purpose simulation program in which these LU factors have to be recomputed every time. Since most of the CPU analysis time is spent in solving linear equations, these techniques can actually speed up the transient analysis of piecewise linear circuits significantly. An experimental circuit simulator has been developed to implement the matrix cache and tested with a few piecewise linear power electronic circuits. The results indicate a speed increase of 2–10 times as compared with its non-matrix cache version.

Introduction to Linear Circuit Analysis and Modelling

Computationally efficient large-change statistical analysis of linear electronic circuits

This paper presents a few techniques based on an efficient use of memory resources to speed up the transient analysis of piecewise linear circuits, such as power electronic circuits. These techniques use the fact that the matrix in the linear equation solving routines can only have a finite number of different values. Hence, by adding a cache memory management technique to store the LU factor of these matrices for future reuse, the linear equation solver can be performed much faster than that of a general purpose simulation program in which these LU factors have to be recomputed every time. Since most of the CPU analysis time is spent in solving linear equations, these techniques can actually speed up the transient analysis of piecewise linear circuits significantly (100-600%).

Approximation properties of a PWL circuit model of hysteresis

Linear circuit analysis is a foundational course for electrical engineers. Instructors of linear circuit analysis courses have traditionally relied on print textbooks for student learning materials. With the rise of student use of computers and the internet, materials like lecture slides and online videos have also been used for learning materials. Increasingly, traditional textbooks (including online formats) are experiencing a decline, while interactive textbooks are growing in popularity. This paper describes auto-graded learning tools, called challenged activities, from various topics in an online linear circuit analysis textbook. Instructors often assign challenge activities as homework. Each challenge activity has 3-5 levels of increasingly difficult problems. Each level randomly generates a question from a large set of questions of similar difficulty. Students must correctly answer a question in a level to progress to the next level. This paper describes the student usage of 4 challenge activities in an online circuit analysis textbook. The average time spent per activity was under 10 minutes and the vast majority of students who started a level ended up completing that level, indicating little attrition. In fact, most levels had 0% of students give up and the highest was only 8%, which is remarkably low based compared to more traditional paper-and-pencil activities based on the teaching experience of the authors.

Analysis of large linear mesh circuits is critical in modern IC extraction and verification tools due to the complex 3-D effects associated with parasitic coupling through interconnects and the chip substrate. The limited availability of computer resources, however, is a major obstacle in the fast and accurate analysis of such circuits. This paper introduces a technique that divides the mesh into a number of partitions, develops macromodels of each partition using a compaction technique and then combines them in a nested fashion to determine a macromodel for the original mesh circuit, which can then be used in simulation. This method makes much better use of CPU time and memory and allows for the fast analysis of extremely large meshes.

The paper presents an optimisation approach to the investigation of piecewise linear convex circuits. The problem is formulated in terms of the objective function and linear equality constraints applied to the diode circuits. Two efficient techniques for solving such a problem are presented. One is based on the active constraints strategy and implemented in the form of a numerical program, and the second one is based on the neural principle and implemented in analogue circuitry, solving the problem in real time. Results of numerical experiments illustrate the theoretical considerations.

Technical note: Measuring separation efficiency of flotation circuits using linear circuit analysis

<div class="section abstract"><div class="htmlview paragraph">In the electrification of automotive and commercial vehicles, batteries are replacing internal combustion engines (ICE) with a battery only power system. The current process uses Linear Circuit Analysis (LCA) and assumes a passive load. The electronics are also assumed to have a constant input voltage from the source. A battery is not capable of providing constant input voltage under automotive use cases resulting in LCA not be applicable for all cases. The non-constant battery voltage will also influence the way electronics are modelled. One specific instance is an EV especially with the traction drive motors where the power demands are considered non-passive.</div><div class="htmlview paragraph">The research will show the discharge behavior of batteries and the results of each of these discharge modes. The research will classify loads as either passive loads or non-passive loads and use the conservation of energy to model non-passive loads with a battery.</div></div>

This paper presents novel free open-source software JuliaCAP for symbolic analysis of linear time-invariant electric circuits in the complex domain of the Unilateral Laplace Transform or Phasor Transform. Modified Nodal Analysis (MNA) has been chosen for formulation of circuit equations in JuliaCAP. JuliaCAP has been developed by Kristina Rajković, Glorija Došlo, Nikola Radojević, Tamara Petković and Ivana Stanojević, at the University of Belgrade - School of Electrical Engineering, Belgrade, Serbia. JuliaCAP is written in Julia, a free open-source (MIT licensed) programming language. Whereas Julia is a relatively new language, there will be some words about it. As a free opensource software package, the underlining algorithm is revealed in full detail, so anybody can get a better understanding of the used methods. We offer JuliaCAP as a useful tool for solving linear time-invariant electric circuits. The future directives should be the improvement of simplifying expressions and the absence of the possibility to solve electric circuits in the complex domain of the Unilateral Laplace Transform. Also, it is shown through examples how this software operates. Electric circuits that are used in examples are Riordan gyrator network, 3rd order Butterworth Low-pass Filter, Subtractor and Adder.

This paper addresses the problem of worst-case tolerance analysis of steady states in linear DC and AC electric circuits. The statement of the problem considered is in the form of linear algebraic equations whose elements are, in the general case, nonlinear functions of a given set of independent interval parameters. Three kinds of solutions are considered: 1) outer solution; 2) inner solution and 3) exact solution. A direct method for computing an outer solution and an iterative method for finding an inner solution are suggested. The inner and outer solutions thus found provide a tight two-sided bound on the exact solution of the tolerance problem investigated. The exact solution can be determined if certain monotonicity conditions are fulfilled. The verification of the conditions involves solving several associated outer solution problems. The computational efficiency of the methods suggested is demonstrated by a numerical example.

Rapid growth in electronic technology makes it difficult to keep track of the device modeling for linear analysis and design. This is particularly hard for MOS transistors. The problem is even more crucial for training engineering students, where they need to be able to hand calculate, put it into circuit format and estimate the design parameters. With transistors model parameters that may run into pages for today's nanotechnology, manually identify the model components and come up with linear equivalent circuits is not easy although it may be a routine data crunching procedure for a modern circuit simulator. One way to get around the problem is to follow two paths. First simulate, or experiment with, the circuit in its original (nonlinear) form, and keep it as the “model”. In the second step, adopt a proper linearizing scheme for the transistors manually, and then modify the model parameters based on the responses received from the model circuit. In our proposed method we do exactly this by using FNPs to modify the parameters in the linearized circuit until the response from the model and that of the linearized circuit fit together.

Recent trends in the scaling down of the conventional transistor size and three-dimensional stacked integrated circuit have increased the importance of transient thermal-awareness in IC floor planning. To this end, this paper will compare the performance of two transient thermal analysis simulation methods: the latency insertion method (LIM) and the Gauss-Seidel (GS) method. By simulating an example thermal problem, we can compare and evaluate the performance of these two analysis methods. The simulated results demonstrate a great superiority in analyzing the speed of LIM from the GS method.

In this article, the linear dynamic analysis of AC generators modeled as RLC circuits with periodically time-varying inductances via Floquet’s theory is considered. Necessary conditions for the dynamic stability are derived. The harmonic balance method is employed to predict the transition curves and stability domains. An approximate expression for the Floquet form of solution is constructed using Whittaker’s method in the neighborhood of transition curves. Numerical verifications for the obtained theoretical results are considered. In accordance with the experimental results, a satisfactory agreement is relatively achieved with the closed experimental literature of the problem.