OpAmp Settling time using wavescan

Have you looked at the settlingTime function? You'll need to read the manual (it's not entirely obvious how to use it), but that might be a more appropriate way of measuring the settling time...

Regards,

Andrew.

Thanks for this. 

Hello Andrew

I tried reading the manual and trying out the settling time calculator function.

I realized that there is something wrong with it.

 Basically it lies with the initial value, final value and the x at y or y.

I hope to hear from your understanding in this matter.

 Thank you 

It might help if you were a little more specific. "something wrong with it" is rather hard  for me to answer - it's a bit like nailing jelly to the wall...

Andrew.

Hello Andrew

Sincere thanks for your reply. I apologised that I explained too vividly just now. I will explain in greater details below.

My input voltage waveform is a pulse wave. Delay time is 50ns. The rise and fall times are 1ns. Pulse width is 100ns. Period is 202s.

I run a transcient analysis for 250ns.

My output waveform goes from -1V to 1V. I can get my output waveform as expected.

But, I want to find out the settling time from -1V to 1V at 0.2% settling time. I use the settling time function in the calculator.

So the 1st and 2nd row in settling time function is: y, value is -1V 

Then the 3rd and 4th row in settling time function is: y, value is 1V 

Percent is 0.2.

But the answer gives me ERROR.

Kindly advise.

Hope to hear from you soon :-)

Regards

Hello chiangliang,

1.  Both the Wavescan UI and docs are incorrect for settlingTime.  See Cadence OnLine Support solution 

http://support.cadence.com/wps/mypoc/cos?uri=deeplinkmin:ViewSolution;solutionNumber=11653262

for more information.  You will need to login with your username and passwd

The UI for the settlingTime function in the Wavescan calculator in IC5.1.41 shows the following two fields:

- Initial Value Type: [x at y] or [y]

- Final Value Type: [x at y] or [y]

These are wrong and should show instead

- Initial Value Type: [y at x] or [y]

- Final Value Type: [y at x] or [y]

Note, the UI fields are wrong but the results are correct.  

This issue only affects 5.1.41 Wavescan.  5.1.41 AWD and 6.1.4 ViVA are unaffected.

2.  You need to post the exact error message (cut and paste) whenever you post a question regarding an error message.

3. Cadence Customer Support (support.cadence.com) is probably where you need to be asking this question. 

Best regards,

Tawna 

Dear Tawna

Thank you so much for your prompt reply. I really appreciate your kindness and help.

I tried to go into the link which you provide but it was unsuccessful as there is something wrong with the host id.

I am currently a PhD student, pursuing my postgraduate studies in Singapore, Nanyang Technological University. I tried to mail the customer support but they replied saying that they would only entertain queries made by supervisors/professors. They will not answer queries by students.

I sincerely hope that you would do me a favour by attaching a file to me that contains information with regard to the link that you mentioned which is re-stated below:

http://support.cadence.com/wps/mypoc/cos?uri=deeplinkmin:ViewSolution;solutionNumber=11653262

Hope to hear from you soon :-)

Sincere Thanks

Regards

Chiang Liang

Hello Tawna

I am able to log in to the online support solution to find out the problem already with my HOST ID.

However, my cadence(5.1.41) problem still persists. 

My output voltage waveform goes from -1V to 1V. Delay time for rise and fall is 1ns. Period is 200ns.

I want to calculate the settling time for 0.2%. Hence, in the calculator:

Initial Value type: y

Initial Value: -1

Final Value type: y

Final Value: 1

Percent: 0.2

The error message is: Evaluation error(Unknown scalar data type: nil) Expression: settlingTime(wave_10() -1 nil 1 nil .2 nil "time")

Kindly need your assist and advice.

Hope to hear from you soon.

Regards

Chiang Liang

 Hi Chiang Liang,

It would be a good idea to contact Cadence Customer Support at this time and send them your entire CDS.log file.  A Support AE can look at the subversion that you are using, the entire error message (and events leading up to the error message). 

best regards,

Tawna

Hello Andrew,

can you receive a 2 slide ppt concerning a settling time measurement question? (a picture would easily do the trick of explaining well)

Jorge