LTspice voltage measurement

Question

How do I measure voltage between two nodes when neither of them is ground? In the schematic below, I want to measure the voltage between nodes Vmic and Vx. Is it just (Vmic-Vx)? I'm afraid that gives a wrong answer.

related, possibly a duplicate: https://electronics.stackexchange.com/questions/204096/how-to-plot-voltage-drop-across-a-specific-component-in-ltspice/204097#204097 — PlasmaHH, Jan 29 '23 at 20:31

score 7 · Answer 1 · answered Jan 29 '23 at 12:56

7

In addition to the other answers, in LTspice you can identify in any command the voltage across two nodes with the syntax

V(node1,node2)

which in your case becomes

V(Vmic,Vx)

answered Jan 29 '23 at 12:56

Massimo Ortolano

835
9
16

That will be useful for quick analysis. Thank you. – blackblade Jan 29 '23 at 13:25

score 5 · Answer 2 · answered Jan 29 '23 at 11:52

5

Use a differential voltage probe.

Click on the first node, and drag to the second node.

answered Jan 29 '23 at 11:52

Neil_UK

166,079
3
185
408

Nice. This can be used when viewing simulation window. – blackblade Jan 29 '23 at 13:24

Andy aka · Accepted Answer · 2023-01-29T13:27:18.237

4

You can use .meas Vmicpk MAX(V(Vmic)-V(Vx))*1000

Is it just (Vmic-Vx)?

Vmic and Vx are node names and not voltages.

The voltages associated with each node are V(Vmic) and V(Vx)

The difference voltage between the two nodes is V(Vmic)-V(Vx)

Then multiply by 1000 if that's what you want.

edited Jan 29 '23 at 13:27

answered Jan 29 '23 at 12:25

Andy aka

456,226
28
367
807

Thank you for the answer. – blackblade Jan 29 '23 at 13:24
2

You can also use V(Vmic,Vx). – Hearth Jan 29 '23 at 20:39

LTspice voltage measurement

3 Answers3