Spice — Circuit __link__

// Set initial condition .IC V(VOUT)=1.5

R1 1 2 1k → Resistor R1 between nodes 1 and 2, 1 kΩ. Basic Components | Component | Prefix | Syntax Example | Meaning | |-----------|--------|----------------|---------| | Resistor | R | R1 1 2 1k | 1 kΩ | | Capacitor | C | C1 2 3 10u | 10 µF | | Inductor | L | L1 3 0 100m | 100 mH | | Voltage source | V | V1 1 0 DC 5 | 5V DC | | Current source | I | I1 2 0 DC 1m | 1 mA DC |

.OPTIONS plotwinsize=0 ; prevents waveform compression spice circuit

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 0 1n 1n 50u 100u) ; 5V square, 10 kHz R1 IN OUT 1k C1 OUT 0 0.1u // Set initial condition

[ComponentName] [Node1] [Node2] [Value]

.OP Sweeps frequency, plots gain/phase (Bode plot). Syntax: .AC oct 100 1 1Meg → 100 points/octave from 1 Hz to 1 MHz. Transient Analysis (

// 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.