How to calculate INL,DNL in cadence spectra

[satya193]

Hi.....
I am new to cadence environment so please let me know
How to calculate INL,DNL of Flash ADC using cadence spectra ? Should i use matlab or anything else.....


Thanks

 

[dick_freebird]

First you need to simulate the full input sweep, picking
off the actual input voltage value at each code transition
and subtracting from it the ideal transition value. Store
all of these (0 - 2^N-1) and use either Ocean code or
an external tool to process the individual bit errors to
get DNL (max()) and INL (I forget, something like
sum()/2^N I guess).

There are ways to make it cleaner in simulation, like
using an ideal DAC off the ADC outputs and a vcvs to
subtract the ADC-DAC voltage from input voltage for
a zero-baseline error signal, that then might be
sampled on timebase, etc. - or at least cleaner for
the analysis point-tool, when that data is printed-to-
file.

 

[satya193]

Thanks a lot for ur reply.....
I have simulate the ADC and got the waveform.
Plz let me know how could I pick actual code transition from that waveform.
Do i subtract it from ideal value manually or any is it possible to do with any program ?
After that how could it will be stored ?

 

[raika]

can anyone help us?
i want to calculate DNL&INL in cadence.
should i export data and use them in matlab? how i do it?
or i can directly calculate them?