SPICE

SPICE (Simulation Program with Integrated Circuit Emphasis) is the industry-standard, general-purpose software for simulating analog electronic circuits: predicting performance before prototyping.

SPICE is the foundational technology for electronic circuit simulation, originally developed at the University of California, Berkeley. It performs critical nonlinear DC, nonlinear transient, and linear AC analyses, modeling circuit behavior with high precision. The software handles a wide range of components: resistors, capacitors, inductors, and key semiconductor devices like BJTs, JFETs, and MOSFETs. Modern, enhanced versions, such as Analog Devices' LTspice, remain essential tools for engineers globally, ensuring design integrity and predicting real-world performance for complex integrated circuits and board-level systems.

https://www.analog.com/en/design-center/design-tools-and-calculators/ltspice-simulator.html