Tersa: Circuit Simulator

Build, simulate and tune analog and RF circuits locally. Explore plots and Smith charts, with projects that remain available even when you are offline.

Tersa is a touch-first workspace for learning, reviewing, and tuning small analog and RF circuits on iPhone and iPad.

Build editable schematics, configure DC operating point, DC sweep, AC and transient analyses, and inspect measurements on clear plots. For linear two-port work, review S11, S12, S21 and S22, return and insertion loss, and raw complex data on a Smith chart.

Use local sample projects to explore RC and LC filters. Change supported component values with the tuner and run the analysis again without rebuilding the project. Import supported SPICE model cards and subcircuits when a circuit needs them.

Simulation runs locally on the device. Results depend on the circuit, models, and numerical settings and must be independently verified before fabrication or safety-related use.