Tersa EDA

Tersa EDA documentation

Schematic components

Reference for Tersa's built-in components, parameters, and practical use.

This chapter documents the built-in Tersa component library. It covers placement, wiring, editing, model selection, and the component groups available in the schematic editor.

  1. Open a schematic and the Components panel.
  2. Select a component. Tersa places it in the nearest free area of the current viewport.
  3. Drag the component into position. Pins snap to the grid.
  4. Touch a pin and draw a connection to another pin. Touching an empty point adds a route point.
  5. Open the Inspector to edit parameters and choose a model.

When the visible area is full, a new component appears next to the existing schematic outside the viewport. Use Fit all to frame the complete document.

  • One finger: select, move, and draw a wire.
  • Two-finger movement: zoom and pan.
  • Brief two-finger tap while wiring: remove the last route point; if there are no points, cancel the connection.
  • Brief two-finger tap with a component selected: rotate it by 90 degrees.
  • Marquee selection: select components and nodes for group movement or deletion.

A completed connection, group move, and rotation are each recorded as separate undo/redo operations.

  • Enter values with units in the Inspector. Numeric fields support exact editing and drag adjustment.
  • Model selects a SPICE model or subcircuit. A built-in generic model is suitable for early experiments; use an imported manufacturer model for a specific device.
  • Pins have a stable order used by the netlist generator. Labels beside pins are electrical net names, not decorative text.
  • Ground defines node 0. Most SPICE analyses cannot produce a valid solution without a reference node.