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I have a very basic question about connecting voltage sources to circuits in LTSpice.

  • I started with the macromodel test fixture for the OP27.
  • I really like the way the positive and negative rails are defined in the macromodel test fixture. I would like to use the same approach for a noise source.
  • I would like to connect my noise source below to R3.
  • I am unclear as to how I would connect the noise source to R3 in the LTSpice interface. It is probably very simple. But, I have not found any instructions on how to do this.

I know that I could move the noise source close to the circuit and attach it with a wire. I would like to connect the noise source in the same way that the op amp rail sources are connected.

Do I need to manually edit the SPICE netlist or can I connect the noise source in the LTSpice interface?

Could someone point me to any references that might describe the steps?

enter image description here

The following circuit works. However, I would really like to put the noise source over to the side with the op amp rail voltages.

enter image description here

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Reset to default
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You can add labels in the LTSpice GUI to give a net a specific name. The default hot key for this is f4 I believe, but there’s an option in the toolbar for this as well. Just add a label to the noise source and another label with them same name to R3.

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  • \$\begingroup\$ Or, draw a wire (F3) from the noise source to R3. Be sure to specify a value for R3. Beware, Vin will short out the noise source. If you want the noise superimposed on Vin, then connect the noise source in series with Vin. You'll need to take a crash course in editing schematics in LTspice. Do an Internet search for "ltspice schematic tutorial" and you'll get lots of hits. This site seems to cover the basics. \$\endgroup\$
    – qrk
    Commented Jan 18, 2022 at 1:17

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