// Include a model file .INCLUDE my_transistors.lib
// End simulation .END | Tool | Best for | |------|-----------| | LTspice | General analog, power electronics, education | | ngspice + KiCad | PCB design integration | | Qucs-S | RF and microwave (with ngspice backend) | | Micro-Cap 12 | (now free) Educational, extensive models | Final rule: Simulate first, then build. But when simulation and reality disagree – trust your oscilloscope. SPICE models are only as good as their parameters. spice circuit
Seeing startup, switching, or pulse responses. 4. Complete SPICE Example (LTspice Syntax) Circuit: Simple RC low-pass filter with a 10 kHz square wave input. // Include a model file
1. What is SPICE? SPICE is the industry standard for analog circuit simulation. It solves Kirchhoff’s laws numerically to predict DC, AC, and transient behavior before you build a physical prototype. Seeing startup, switching, or pulse responses
.OPTIONS plotwinsize=0 ; prevents waveform compression
.OP Sweeps frequency, plots gain/phase (Bode plot). Syntax: .AC oct 100 1 1Meg → 100 points/octave from 1 Hz to 1 MHz.
Designing filters, amplifiers, or checking stability. 3. Transient Analysis (.TRAN) Plots voltage/current vs. time. Syntax: .TRAN 1u 10m → timestep 1 µs, stop at 10 ms.