# LTspice Simulation Question

#### raventrob

Joined Jan 28, 2020
4
Hello All,

Currently I've been doing some parametric sweeps with components and temperature. If I perform both a parametric sweep with a temperature sweep is there a way to extract or plot the data for one of the temperature points? For example lets say I perform a transient sweep while measuring "Vout" and stepping a resistor over some range while simulating ".temp 0 100 10", can I plot or extract lets say just the data for 50C?

Thank you

#### ericgibbs

Joined Jan 29, 2010
11,571
hi raven,
Welcome to AAC.
Please post your LTS asc file so that we can run it.
E

#### raventrob

Joined Jan 28, 2020
4
@ericgibbs So basically what I'm doing is a little more complicating then what I described in the original post.

I am sweeping the input power level from -30 dBm to 0 dBm and then using the .meas function to obtain the RMS voltage for the input and output nodes then using some math to convert to dBm so that I can plot Pin vs Pout using the Spice Error Log. What i'd like to do is simulate for 3 different temperatures and plot 3 different Pin vs Pout traces, the problem is I cant distinguish the temperature data from each other when I go to plot.

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#### eetech00

Joined Jun 8, 2013
2,182
Hello All,

Currently I've been doing some parametric sweeps with components and temperature. If I perform both a parametric sweep with a temperature sweep is there a way to extract or plot the data for one of the temperature points? For example lets say I perform a transient sweep while measuring "Vout" and stepping a resistor over some range while simulating ".temp 0 100 10", can I plot or extract lets say just the data for 50C?

Thank you
hi

look in the error log file and determine which step number represents 50C.
Then, in the plot window, add to the window label @(the step number)
Example

pout@10

eT

#### raventrob

Joined Jan 28, 2020
4
Okay look at my picture below. As you can see the data I want for "Pout" is shown and I know all the even step numbers are 25C and all the odd numbers are 50C. So you are saying I can specify which step numbers to plot? @ericgibbs

#### eetech00

Joined Jun 8, 2013
2,182
Okay look at my picture below. As you can see the data I want for "Pout" is shown and I know all the even step numbers are 25C and all the odd numbers are 50C. So you are saying I can specify which step numbers to plot? @ericgibbs

View attachment 197755
Yes you can.

Like I showed in post #4

eT

#### raventrob

Joined Jan 28, 2020
4
@ericgibbs Gah I feel like I'm so close, thank you for the help so far.

I just am getting this syntax error when I add a trace to the plot plane.

#### eetech00

Joined Jun 8, 2013
2,182
Hello

Open the log file.

Locate the data for "pout"

Right-clk on "pout", then select "plot stepped .meas data"
A plot window will open.
Click in the plot window, rht-clk and select "add trace"
select "pout", it will be displayed in the plot window
you can change the axis' as desired.

eT

#### eetech00

Joined Jun 8, 2013
2,182
@ericgibbs Gah I feel like I'm so close, thank you for the help so far.

I just am getting this syntax error when I add a trace to the plot plane.

View attachment 197757
You can't add the trace that way.

Click the signal name once so it shows in the plot window, then change the label to output@1 etc.
do this three times.

eT