Back to Forums
4 posts / 0 new
Last post
#1 Feb 19, 2018
putzer_philipp
Offline
Last seen: 6 years 1 month ago
Joined: 2018-02-19 05:15

Evaluate Measurement XatY,

Hi there,

I'm searching for a function in the Probe window to evaluate the X value of a DC sweep (in the case here the input voltage) at a certain Y position. Saying: X @ Y(where Y = somevalue)

I want to run a MC Analysis and I have to check how the threshold is changing as function of the input voltage and tolerance.

There is a function YatX and also some functions XatMin/XatMax but I have to search for a dedicated value and not for min/max values

 

Does anybody know a possible solution for this?

thanks

philipp

 

Wed, 2018-03-07 07:28
RobertoGb
RobertoGb's picture
Offline
Last seen: 5 years 10 months ago
Joined: 2016-05-24 03:10

Hello,

I am not sure it makes sense. It is possible as you mentioned to automatically show the X value for a maximum Y value of a set of traces (XatYmax). However, how do you want to look for the value of X for a Y value of a set of traces? How can you guarantee that such Y value is going to be presented in each trace? In my opinion it does not make any sense. The only possibility here is look for a Y value for a particular X value of a set of traces.

I hope it clarifies. Let me know you opinion.

Regards

Thu, 2018-03-08 03:10
putzer_philipp
Offline
Last seen: 6 years 1 month ago
Joined: 2018-02-19 05:15

Hi Roberto,

I try to describe what I have as a simulation output, then my whish for the function X at Y is more clear.

I make a DC sweep and measure the current through a LED string. The LEDS are bypasses by a FET in case that the input voltage is too low. Depending on the forward voltage range of the used LED, the circuit switches a little bit earlier or later than wanted. For this I added a DEV value for the parameter and made a MC analysis. Now I want to fix my Y value to let's say 80% of the maximum value. Then I want to evaluate how the X-axis (in this case the input voltage of the circuit) changes as a function of the forward voltage. So I would be able to plot this in a histogram.

I could also send you a picture of the simulation output if this helps.

 

thanks a lot

philipp

Thu, 2018-03-08 05:24 (Reply to #3)
RobertoGb
RobertoGb's picture
Offline
Last seen: 5 years 10 months ago
Joined: 2016-05-24 03:10

Hi,

Yes, I think it helps a little bit. I think you could use the measurement XatNthY. In this function you have to introduce the Y_value you are looking for and you get as result the X_value. 

If this does not help, please share an image of the probe window with your traces.

Regards,

Roberto

Download PSpice and try it for free! Download Free Trial
Cadence