Component models

A Part defines the symbol and electrical pins. Its Model defines how one placed component behaves during simulation. Model selection is independent for every model-backed component, so a circuit can mix compact and detailed models.

Model scope

The first model listed for a model-backed Part is its default. Later entries add named electrical effects such as conduction resistance, charge storage, bandwidth, or propagation delay. Parameters with a datasheet reference condition are calibrated at that stated operating point.

Additional parameters do not establish device accuracy. Each page defines the equations, fixed assumptions, and omitted behavior for that model.

Equation notation

$\operatorname{clip}(x,a,b)=\min(\max(x,a),b)$ limits a value to the closed interval from $a$ to $b$. $\operatorname{uramp}(x)=\max(x,0)$, while $u(x)$ is zero below 0 and one at or above 0.$V_T=25.852\,\mathrm{mV}$ is the fixed thermal voltage used for semiconductor calibration at 27 °C. Primed voltages are internal limited values, and $q$ is a binary state variable. The equations state OhmSpice's parameter transformations and macromodels; native semiconductor elements retain their continuous SPICE device equations.

Model reference

These pages follow the order shown in each Part's Model control. A single-model Part omits the redundant selector in the inspector. Resistors, capacitors, and inductors do not expose Model choices; their primary value directly defines their ideal element behavior.

Analysis qualification

Each model page lists the qualified analyses. OhmSpice blocks a run when a selected model does not support that analysis. This prevents a switch or comparator state from being presented as a meaningful small-signal AC result.