Discussion Overview
The discussion focuses on the internal workings of SPICE simulators, particularly how they perform calculations related to electronic components like transistors and the methods they use to solve systems of equations. Participants express interest in both the modeling of specific devices and the general computational techniques employed by SPICE.
Discussion Character
- Exploratory
- Technical explanation
- Conceptual clarification
Main Points Raised
- One participant seeks detailed information on the internal operations of SPICE simulators.
- Another participant mentions the Ebers-Moll model for bipolar transistors and suggests that the answer may vary depending on the specific version of SPICE being used.
- A different participant questions the existence of a generic FET model and references a specific version of SPICE (hspice) that includes detailed descriptions of FET models.
- It is noted that SPICE uses modified nodal analysis to set up a system of equations and employs Newton's method combined with the trapezoidal rule for time-stepping.
- One participant expresses a desire to understand the complexity behind how SPICE utilizes input parameters beyond modified nodal analysis.
- Another participant explains that SPICE reads elements from the input file and stamps constitutive relations into a matrix connecting nodes, detailing the process for linear and nonlinear systems, including the use of Jacobians and numerical techniques for solving equations.
- A participant reflects on the simplicity of the concepts discussed but expresses frustration at the difficulty of finding detailed information online.
Areas of Agreement / Disagreement
Participants generally share insights and clarifications about SPICE's internal workings, but there is no consensus on the availability of comprehensive resources or the complexity of the internal processes. Multiple viewpoints on specific models and methods remain present.
Contextual Notes
Some discussions involve assumptions about the complexity of SPICE's internal calculations and the specific models used for different types of transistors, which may not be universally applicable across all versions of SPICE.