<simulation.pcbreturncurrentsimulation />

<simulation.pcbreturncurrentsimulation /> declares a pending PCB return-current experiment. Import simulation from "tscircuit" and place the element inside a board or subcircuit. Add one or more <simulation.pcbreturncurrentexcitation /> children to select the routed signals and their physical return contacts.

The preview shows the PCB being measured. Rendering records the experiment in Circuit JSON; it does not run an electromagnetic solver or produce current plots.

import { simulation } from "tscircuit"

export default () => (
  <board width={8} height={6} layers={2} thickness={0.8} schematicDisabled>
    <net name="GND" />
    {[-2, 2].map((x, index) => (
      <chip
        key={index}
        name={index === 0 ? "U1" : "U2"}
        pcbX={x}
        pinLabels={{ pin1: index === 0 ? "OUT" : "IN", pin2: "GND" }}
        footprint={
          <footprint>
            <smtpad portHints={["pin1"]} width={0.8} height={0.8} shape="rect" />
            <smtpad portHints={["pin2"]} pcbY={1.5} width={0.8} height={0.8} shape="rect" />
          </footprint>
        }
      />
    ))}
    <trace name="SIGNAL" from=".U1 > .OUT" to=".U2 > .IN" thickness={0.18} pcbStraightLine />
    <trace from=".U1 > .GND" to="net.GND" />
    <trace from=".U2 > .GND" to="net.GND" />
    <simulation.pcbreturncurrentsimulation name="Signal return">
      <simulation.pcbreturncurrentexcitation
        source=".U1 > .OUT"
        load=".U2 > .IN"
        trace=".SIGNAL"
        ground="net.GND"
        current="5mA"
        sourceImpedance="25ohm"
        loadImpedance="100ohm"
        returnSource=".U2 > .GND"
        returnSink=".U1 > .GND"
      />
    </simulation.pcbreturncurrentsimulation>
  </board>
)

Properties

Property	Description
name	Optional nonempty experiment name. Defaults to "PCB return current".
children	Nested <simulation.pcbreturncurrentexcitation /> elements.

Multiple declarations create independent experiments. An empty declaration can reserve an experiment, but it needs an excitation before it can be simulated. PCB-disabled rendering skips these declarations.

Running the experiment

Export the rendered Circuit JSON and pass it to the simulate-return-current CLI. Select the experiment if more than one exists. Frequency, mesh/sampling settings, physical stackup, copper model, and solver configuration are CLI run parameters, not properties on this element. Read the resulting Circuit JSON separately.

An experiment can contain multiple excitations on different routes sharing one ground net. To compare currents, directions, or ground nets for the same route, use separate experiments.

The flat <pcbreturncurrentsimulation /> form accepts the same properties.