Hi. I have a simple simulation which steps a circuit parameter over two values giving a different pk2pk output voltage for each. Using ".meas TRAN Vpp PP V(Out)" I can capture those two levels. This works fine.

How do I then display the ratio of the two results? This is effectively displaying Vpp@1/Vpp@2. I really have searched for an answer and can't find any advice elsewhere. I feel sure it must involve @1 and @2 but I can't find a format to make that work.

 

Hi bord,
Please post your LTS asc file and any models used in the circuit
E

 

Ok but it is simple enough. It's really the principle and syntax I want, nothing to do with the circuit. Here is a basic (very) example of what I am trying to do. I think everything should be self explanatory from the sim itself. Just in case, it simply generates two voltage measurements according to the value of the feedback resistor at the time. I want to then generate and display the value of:

Result Pass1 / Result Pass 2
I had thought maybe something based on V(out)@1 / V(out)@2

I did come across a post where someone wanted something similar and was advised to try
.MEAS NOISE 10Hz_SNR FIND V(onoise)/V(onoise)@1 AT=10Hz

That is with his own variable names of course. I've tried things based on that syntax but can't seem to kick it into action.

 

Hi bord,
Is this basic sim giving the result you are asking?
Vo1/Vo2
If not please supply more information
E

 

To use:
.meas A param Vpp@1/Vpp@2

 

Sorry Eric, I obviously didn't give you enough info at the start. It isn't to display the value as a plot trace, I am trying to calculate the value then post it in the Output Log. Bordodynov is on the mark there. From his line I have it up and working. It's a kind of a "Durrhhh!" moment when you see it solved as simply as that.

However, it does report the answer in dB and I need a simple ratio. I'll get to work on converting it now.

Thanks to both of you for your help, sorry I wasn't clear Eric. (Incidentally, that opamp model is your own from your [zzz] Bordodynov!)