SPICE Simulation

Overview

tscircuit supports SPICE simulation to analyze the analog behavior of your circuits. You can define voltage sources with various waveforms, place probes to measure voltages, and configure the simulation parameters. The results can be visualized to understand how your circuit performs over time.

Simulation Components

<analogsimulation />

This component configures and enables the analog simulation for the board.

Property	Type	Description
duration	number	The total duration of the simulation (e.g., in seconds).
timePerStep	number	The time interval between simulation steps (e.g., in seconds).
spiceEngine	string	The SPICE engine to use (e.g., "ngspice").

Example:

<analogsimulation
  duration={0.01}
  timePerStep={1e-6}
  spiceEngine="ngspice"
/>

Probes

Probes are used to specify which parts of the circuit you want to measure. These do not have a physical representation on the PCB.

<voltageprobe />

Measures the voltage at a specific point in the circuit.

Property	Type	Description
connectsTo	string	A port selector indicating where to place the probe.

Example:

<voltageprobe connectsTo=".R1 > .pin1" />

<voltagesource />

For simulations, <voltagesource /> can be configured to produce various waveforms beyond a simple DC voltage.

Property	Type	Description
waveShape	string	Shape of the voltage wave. Can be "dc", "sine", "square", "triangle".
frequency	string or number	Frequency of the waveform (e.g., "1kHz" or 1000).
amplitude	string or number	Amplitude of the AC signal. For square waves, this is the peak voltage.
offset	string or number	DC offset of the waveform.
dutyCycle	number	For square waves, the fraction of the period the signal is high (0 to 1).

Example: Boost Converter

Here is an example of a boost converter circuit configured for SPICE simulation. It uses one voltage source (V2) with a square wave to drive a MOSFET, boosting the voltage from a 5V DC source (V1) to a higher level. Voltage probes are placed at the input and output to observe the results.

export default () => (
    <board width={30} height={30} schMaxTraceDistance={5}>
      <voltagesource
        name="V1"
        voltage={"5V"}
        schY={2}
        schX={-5}
        schRotation={270}
      />
      <trace from={".V1 > .pin1"} to={".L1 > .pin1"} />
      <trace from={".L1 > .pin2"} to={".D1 > .anode"} />
      <trace from={".D1 > .cathode"} to={".C1 > .pin1"} />
      <trace from={".D1 > .cathode"} to={".R1 > .pin1"} />
      <trace from={".C1 > .pin2"} to={".R1 > .pin2"} />
      <trace from={".R1 > .pin2"} to={".V1 > .pin2"} />
      <trace from={".L1 > .pin2"} to={".M1 > .drain"} />
      <trace from={".M1 > .source"} to={".V1 > .pin2"} />
      <trace from={".M1 > .source"} to={"net.GND"} />
      <trace from={".M1 > .gate"} to={".V2 > .pin1"} />
      <trace from={".V2 > .pin2"} to={".V1 > .pin2"} />
      <inductor 
        footprint={"0603"} 
        name="L1" 
        inductance={"1mH"} 
        schY={3} 
        schX={-1} 
        pcbY={3} 
      />
      <diode
        name="D1"
        footprint={"0603"}
        schY={3}
        schX={2.1}
        pcbY={6}
        pcbX={3}
      />
      <capacitor
        polarized
        schRotation={270}
        name="C1"
        capacitance={"10uF"}
        footprint={"0603"}
        schX={3}
        pcbX={3}
      />
      <resistor
        schRotation={270}
        name="R1"
        resistance={"1k"}
        footprint={"0603"}
        schX={6}
        pcbX={9}
      />
      <voltagesource
        name="V2"
        voltage={"10V"}
        waveShape="square"
        dutyCycle={0.68}
        frequency={"1kHz"}
        schX={-3}
        schRotation={270}
      />
      <mosfet
        channelType="n"
        footprint={"sot23"}
        name="M1"
        mosfetMode="enhancement"
        pcbX={-4}
      />
      <voltageprobe connectsTo={".V1 > .pin1"} />
      <voltageprobe connectsTo={".R1 > .pin1"} />

      <analogsimulation
        duration={100}
        timePerStep={1}
        spiceEngine="ngspice"
      />
    </board>
)

The simulation results would show the output voltage across R1 successfully "boosted" compared to the 5V input from V1. The specific output voltage depends on the duty cycle of the MOSFET driver V2 and the component values.