Hello.
 I have simulaion results of a differential folding amplifier for an A/D converter.

 I want to find out the zero crossings of the output waveforms. I found some article online, which found the zero crossing on the time scale using the calculator feature cross. I tried it and it doesnot work for me.

 Any suggestions on how can I get the zero crossings or basically plot the difference between 2 outputs of a differential amplifier.
 
 Thanks in advance !

Andrew,
 Thankyou very much for the reply. Actually, what I did was, select the wave button on the calculator and then select one of the waveform on my waveform window. Then I clicked on the cross button and then buffer output or something.

  I am using this for the first time and just followed the procedure,trying to see if something happened.But,I feel what you said is right, subtract the signal first.

   Can u just give me a brief idea on how to subtract signals and then plot zero cross or is there any documentation available that I can refer to.

    Thankyou once again.

Thanks Andrew,
  Your suggestion was very helpful, I was able to do it.

Regards,
Vinit.

Vinit,

Sounds like a good reason to write an OCEAN script to do this. You can then write some code to loop over the differential pairs and do the same computation on each, and print out the results.

Look in the OCEAN Reference Manual in cdsdoc (I think it is under the  Analog Design Environment, or something like that, in cdsdoc - I'm writing this from memory).

Regards,

Andrew.

Thankyou guys,
  I really appreciate your replies.  I think I am not able to make it clear what I want to do. Let me give it a try.

  Actually, I am trying to simulate 18 Folding amplifiers(folding rate = 5) together in some fashion. Each folding amplifier output generates 5 zero crossings and hence I have 90 zero crossings.
 
   Initially, I had problems of getting this zero crossing point on the Y-axis, which problem is now solved.

   Now, I am trying to study the variation in these zero crossings if I vary some other parameter. Hence I wanted to know a few things:

-- If I can get the value(x-axis) of these 90 zero crossings(ideal) so that I can compare them with the zero crossings after I introduce some mismatch. As you understand, it would be too difficult to first generate the zero crossing for each folding amplifier, note down the 90 values,then generate zero crossings with mismatch and measure each value and compare with the ideal value.

--So is it possible to automatically measure these values and print  to file, so that I can compare them easily.

I really thankyou for your help.

Regards,
Vinit.