INL simulation in Cadence

[nguyenvanthien]

Hi all,
I'd like to simulate INL using Calculator in Cadence. However, I haven't understanded clearly about inl function. Anyone can explain for me. Thanks

 

[erikl]

Check this AN: View attachment Atmel_Data_Converter_Terminology.pdf

 

[nguyenvanthien]

Check this AN: View attachment 132371

Thank you for documents. It 's very useful. However, I'd like to know about function "inl" in Calculator; how set up parameters?
https://obrazki.elektroda.pl/8516975900_1474526036.png

 

[erikl]

When I was using the Calculator (5.1.41), no such function was available, sorry. We had to extract INL as the maximum difference between the received spectrum and the expected linear line, s. Fig. 1b. of this Maxim AN . Represent these curves and try and find the appropriate parameters.

See here INL & DNL result curves for a 10bit ADC:

 

[nguyenvanthien]

Virtuoso 6.1.4 is I'm using. They give example but I applied for my waveforms, results weren't as shape as example.
https://obrazki.elektroda.pl/7473405000_1474617896.png
https://obrazki.elektroda.pl/5066858000_1474617929.png
If we can simulate in Calculator, it ill save more time.

 

[erikl]

Yes, I think the second curve is not correct, but I guess the first one.

Use the Calculator to subtract the ideal normalized curve V(V) = 5V * time(ms)/(256*1.6ms) from the first curve, consider that the result spans 256 LSB, so divide by 256 , this will result in your INL curve.