Spice++
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Your first circuit

Open the editor, place parts, wire them, run an analysis and read the result. Your first circuit in Spice++ in a few minutes.

Open the editor

Go to /app and sign in with email, Google or Microsoft. Email accounts are confirmed with a 6-digit code. Companies with single sign-on use the SSO option on the sign-in page.

Place parts

  1. The palette on the left holds the common parts: wire, resistor, capacitor, inductor, voltage and current sources, ground, supply rail, diode and op-amp. Click one, then click the canvas to place it.
  2. Every other part, including named parts such as the LM358, 2N3904 and 1N4148, is in search. Press P or ⌘K and type its name.
  3. While a part follows the cursor, ⌘R rotates it and X mirrors it. Press Esc or right-click to stop placing.

Wire it

  1. Press W for the wire tool.
  2. Click a pin to start, click to add corners, and click a pin or another wire to finish. Double-click also finishes.
  3. Backspace removes the last corner and / flips the direction of the current bend.
Every circuit needs a ground. Place one with G; its node is SPICE node 0.

Set values

Select a part to edit it in the inspector on the right. Values take SPICE suffixes: f p n u µ m k meg g t, and 4k7 means 4.7 k. Note that m is milli and meg is mega.

Sources take a DC value, an AC magnitude for frequency analysis, and optionally a time-domain waveform such as SIN(0 1 1k). See Source waveforms for the full syntax.

Run an analysis

  1. The analysis bar at the bottom left shows the active directive, for example .op or .ac dec 60 10 1meg. Click it to edit, or choose an analysis from the arrow next to Run.
  2. Press Run. Results open in the waveform panel: traces for transient and DC sweeps, magnitude and phase for AC, and a table of node voltages and branch currents for an operating point.
  3. With the panel open, the probe tool is active. Click a node or a part to plot its voltage or current; click two points to plot the difference between them.

Save and share

Designs save as you work. The indicator next to the name reads Saved once your account has the latest copy, or On device if the browser is offline; it syncs when the connection returns.

The menu at the top left lists your designs, the ones shared with you, and the built-in examples. Share opens the sharing settings described in Sharing.