[SOLVED] LTSpice waveform param analysis

[doupg]

Hi Everybody,

I'm using this command on a spice simulation (LTSpice):

.step param Rmin list 1 1k

i.e. I'm just doing an analysis for which I want to analyze the current through a resistor (Rmin) for two different situations: Rmin=1ohm and Rmin=1Kohms.

I plot the current and can I see the two different waveforms.

With Right Mouse Button I can choose "Select Steps" and pick only one waveform (either for Rmin=1ohms or Rmin=1Kohm) if I want.

For my analysis I want to see both waveforms at the same time.

Here comes the question:

when I place the cursors how can I assign let's say cursor1 for Rmin=1ohm and cursor2 for Rmin=1kohm, or if I want to use only one cursor how do I indicate the cursor which step (Rmin=10ohm or Rmin=1kohm) to evaluate and change between them. There must be a short key, but I'm missing it.

Thank you very much!

 

[keith1200rs]

I don't know how to do what you want in LTspice, but it may not be possible. LTspice is a crude graphical processor tagged onto Spice. It is probably not the right time to suggest changing simulators but even the free version of Simetrix will easily do what you want, e.g. parameter or value sweeps, nested sweeps etc. Analog Circuit Simulation Software from SIMetrix Technologies - SPICE

Keith.

 

[doupg]

Thanks for your answer and time. Exactly that is what I wanted: be able to place the cursor(or different cursors) on the different curves for different parameter values.

I saw the image you attached. In LTspice I can see (like in your case) the four curves for different values of R1 but I cannot (or I don't know how to) place the cursor let's say on the green curve (R1=100) and then on the pink curve (R1=10k). In LTspice the cursor is by default on the curve for the first parameter and you cannot change between the different curves.

Thanks also for the software suggestion. I will check it.

Best Regards,

---------- Post added at 15:40 ---------- Previous post was at 15:33 ----------

Hello again Keith and to whom it may concern,

I just found how to do it in LTSpice:

"The attached cursors can also be used to readout which trace belongs to which run of a .step/.dc/.temp set of simulation runs.

You can navigate the cursor from dataset to dataset with the up/down keyboard cursor keys and then right-click on the cursor to see the step information for that run."

i.e. just use the up/down arrow keys to switch between the datasets.

Regards,