16 posts / 0 new
Last post
#1 Mar 11, 2019
tqy1024
Offline
Last seen: 2 months 5 days ago
Joined: 2019-03-11 11:31

Integral Function in Orcad Capture

Hi all,

I am stucked at a very obvious problem, which is basically when I use the format Integral(V(out)*I(out)) to find the power loss for a certain simulation. The software shows me a warning, says this expression is invaild. I am not sure where went wrong. Can anyone please provide any clues about this issue?

 

Sincerely

Mon, 2019-03-11 11:45
aashish
Offline
Last seen: 2 months 1 week ago
Joined: 2016-06-22 23:39

Hi,

 

I beleive OUT is a net and current can't be I(out). Try specifying the current expression as shown in list. It should be like  I(C1) which gives current though C1.

 

Regards

Abhishek

Mon, 2019-03-11 11:52 (Reply to #2)
tqy1024
Offline
Last seen: 2 months 5 days ago
Joined: 2019-03-11 11:31

Thanks for your repley, I tried use V()*I(L).  Same result came out. Actually, I have used multiple group V and I in 'Add Trace', to find out the problem. But unfortunatelly, all failed. I want use this to calculate power loss, so I tried W(x) as well.

Mon, 2019-03-11 11:47
tqy1024
Offline
Last seen: 2 months 5 days ago
Joined: 2019-03-11 11:31

Hi,

Thanks for your repley, I tried use V()*I(L).  Same result came out. Actually, I have used multiple group V and I in 'Add Trace', to find out the problem. But unfortunatelly, all failed.

 

Regards

Mon, 2019-03-11 12:24
ronaks
ronaks's picture
Offline
Last seen: 1 month 3 days ago
Joined: 2018-10-15 09:31

Hi Qiuyang,

In you use equation- W(x), x can only be a PSpice device. If you used x value as a node or another reference name, it won;t work.

Try adding the power dissipation marker from the capture window to the device at which you want to calculate the power loss at.at1.PNG

Please let us know if this worked for you.

 

 

Mon, 2019-03-11 12:37 (Reply to #5)
tqy1024
Offline
Last seen: 2 months 5 days ago
Joined: 2019-03-11 11:31

Thanks for your repley. But the model that I am currently using is not built-in model. I used spice model given by company to do this simulation. I have contacted this problem with SUPPORT TEAM of Cadence. Thet said the format of Integral Function should be exactly same as I wrote, which is Integral(V(x)*I(x)). I really cannot figure out where goes wrong in my case.

Mon, 2019-03-11 12:42
aashish
Offline
Last seen: 2 months 1 week ago
Joined: 2016-06-22 23:39

Hi,


Can you confirm what exact steps you used to add the expresion. You are adding a trace or evaluating measurements ?

 

You should do, Trace > add trace and select plot templates from drop down. then select integral(V(out)*I(R1))

 

Regards

Abhishek

Mon, 2019-03-11 12:45 (Reply to #7)
tqy1024
Offline
Last seen: 2 months 5 days ago
Joined: 2019-03-11 11:31

Yes, That's the way I did, but failed, and the error shown as attached.

Mon, 2019-03-11 13:06
aashish
Offline
Last seen: 2 months 1 week ago
Joined: 2016-06-22 23:39

Hi,

 

There appears to be a space before V(out). try removing it...Simulate it again and then try adding the expression again.

 

Regards

Abhishek

Mon, 2019-03-11 13:10 (Reply to #9)
tqy1024
Offline
Last seen: 2 months 5 days ago
Joined: 2019-03-11 11:31

Actually, it doesnt matter. Find attached

Mon, 2019-03-11 13:19
aashish
Offline
Last seen: 2 months 1 week ago
Joined: 2016-06-22 23:39

Hi,

 

Thhis may need deeper debugging. Create a case on Cadence Online Support such that a dedicated AE can work on this.

 

Regards

Abhishek

Mon, 2019-03-11 13:20 (Reply to #11)
tqy1024
Offline
Last seen: 2 months 5 days ago
Joined: 2019-03-11 11:31

How to create a case on cadence

Mon, 2019-03-11 13:22
aashish
Offline
Last seen: 2 months 1 week ago
Joined: 2016-06-22 23:39

you will need to register on http://support.cadence.com

 

then you can raise cases on it.

 

Regards

Abhishek

Mon, 2019-03-11 13:26 (Reply to #13)
tqy1024
Offline
Last seen: 2 months 5 days ago
Joined: 2019-03-11 11:31

Registered. But cannot see where I can raise this.

Mon, 2019-03-11 18:35
ronaks
ronaks's picture
Offline
Last seen: 1 month 3 days ago
Joined: 2018-10-15 09:31

Hi,

As there is no function for calculating integral in the list below for the analog operators available. I believe that's why you are seeing an error when using the function Integral()

m3.jpg

Please try using PowerDissipation_mW as shown in picture below- Total power dissipation in milli-watts during the final period of time (can be used to calculate total power dissipation, if the first waveform is the integral of V(load). This should give you the value of Power Loss.

m2.png

Let us know if this worked.

Tue, 2019-03-12 06:21 (Reply to #15)
tqy1024
Offline
Last seen: 2 months 5 days ago
Joined: 2019-03-11 11:31

Is this the correct format to use this powerdissipation function? I was going to find out the power loss during turn-on/off transistion, which is basically the cross-section of Ids and Vds during turn-on/off. Anyway, I want to express my gratitude for your help.

ERROR_1.PNG

Download PSpice Lite and try it for free! Get PSpice Lite
Cadence