Ltspice

LTspice is a high-performance (Simulation Program with Integrated Circuit Emphasis) simulator, schematic capture, and waveform viewer with enhancements and models to ease the simulation of analog circuits. Originally developed by Linear Technology (hence the "LT" prefix) and now maintained by Analog Devices (ADI), it has become the industry's de facto standard for free, high-speed circuit simulation. Core Capabilities and Features

LTspice is uniquely positioned in the electronics world because it is without being "crippled" or limited in its node count or capability—a rarity for professional-grade software. The Use of LTspice Digital Simulation in Teaching Solid ltspice