LTspice

About

LTspice is a free SPICE simulator, schematic capture tool, and waveform viewer. Its graphical schematic capture interface lets you probe schematics and produce simulation results, which you can explore further with the built-in waveform viewer. According to the website, LTspice includes enhancements and models intended to improve the simulation of analog circuits compared to other SPICE solutions.

The website also points to resources for learning the software, including tutorials on basic operation, transformers, third-party models, symbols, AC analysis, and noise analysis, as well as tips, articles, keyboard shortcuts, and a library of ready-to-run demo circuits. A library of macromodels and demo circuits for select Analog Devices products is also available.

LTspice is offered as a download for Windows and macOS, and the site lists tools that export .asc schematic files for LTspice, such as the Signal Chain Designer, Analog Filter Wizard, Analog Photodiode Wizard, Precision ADC Driver Tool, and LTpowerCAD.