In my simulation I require Earth on my chassis so that filter could be simulated. But I am not getting how to make an Earth in LTspice.

Please note: This question is regarding ' LTspice ' protective earth grounding and not on filtering. I need to distinguish in between GND (circuit common ) and PE(symbol) to make simulations.

  • \$\begingroup\$ You want your circuit reference ground to be 48 V above earth ground? \$\endgroup\$
    – The Photon
    Jun 5, 2014 at 17:53
  • \$\begingroup\$ I am not sure, My device is floating powered through 48VDC battery, yet I need to divert noise towards earth(The Green-yellow- wire) . \$\endgroup\$
    – Adi
    Jun 5, 2014 at 17:56
  • \$\begingroup\$ What is the source of noise? \$\endgroup\$
    – The Photon
    Jun 5, 2014 at 18:46
  • \$\begingroup\$ PWM Switcher 500KHz. \$\endgroup\$
    – Adi
    Jun 6, 2014 at 7:11
  • \$\begingroup\$ How is it connected to the circuit? \$\endgroup\$
    – The Photon
    Jun 6, 2014 at 17:42

1 Answer 1


SPICE-like simulators like LTSpice don't make any special consideration for the earth node. If protective earth is different from the circuits reference ground, you can just define a new node and call it EARTH or PE or NODE5 or whatever you want.

Remember that current only flows in complete circuits so you will probably have to include some parasitic paths in your model for the earth connection to have any effect on the circuit behavior.

  • \$\begingroup\$ Thanks, I used different nets for these grounds.Now I can measure half voltage at Y-cap , The capacitor is shunting uA current waveform towards earth, which slowly damps after 3ms. Is this how the simulator should work. \$\endgroup\$
    – Adi
    Jun 8, 2014 at 17:53
  • \$\begingroup\$ You'll have to share your schematic for is to be able.to answer that. \$\endgroup\$
    – The Photon
    Jun 8, 2014 at 22:50
  • \$\begingroup\$ I just re-explored , but couldnt see any current going towards new ground node, can you please axplain how to add parasitic path? \$\endgroup\$
    – Adi
    Jun 9, 2014 at 9:28

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.