// 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.
RC Filter Simulation V1 IN 0 PULSE(0 5 0 1n 1n 50u 100u) ; 5V square, 10 kHz R1 IN OUT 1k C1 OUT 0 0.1u spice circuit
// Set initial condition .IC V(VOUT)=1.5 // End simulation
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. RC Filter Simulation V1 IN 0 PULSE(0 5
[ComponentName] [Node1] [Node2] [Value]
.TRAN 1u 1m .AC dec 100 10 100k
.OPTIONS plotwinsize=0 ; prevents waveform compression