Fabio Eboli wrote: > Bruce, Bob, now I have more questions > than before :) > > First and most important: > Where can I find references about the > statistical method you mentioned? > I tried to search online but didnt't find > any info. http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=4030739&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D4030739 <http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=4030739&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D4030739> is one of the best in that it gives guidance on selecting suitable test oscillator periods. It also details how the integral linearity can be derived from the test. There are a couple of minor errors in the paper. Bruce

Fabio Eboli wrote: > Bruce, Bob, now I have more questions > than before :) > > Fabio. > > P.S. The micro's adc is charachterized > for total unadjusted error of +-2LSB Max > at 25°C, 12bit total. > It's s-h is 8pF with 1kohm in series, > probably I can sync the sampling to > open just before the pulse, and close > after the fact. What error is that: gain error? offset error? integral nonlinearity? What about monotonicity or differential linearity? A worst case assumption would be that the ADC is perhaps only monotonic for the 11 most significant bits. Bruce

> > http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=4030739&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D4030739 > <http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=4030739&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D4030739> > is one of the best in that it gives guidance on selecting suitable > test oscillator periods. > It also details how the integral linearity can be derived from the > test. > There are a couple of minor errors in the paper. > > Bruce Thank you for the references, unfortunately I dont have an account to access to IEEE papers. >> P.S. The micro's adc is charachterized >> for total unadjusted error of +-2LSB Max >> at 25°C, 12bit total. >> It's s-h is 8pF with 1kohm in series, >> probably I can sync the sampling to >> open just before the pulse, and close >> after the fact. > What error is that: As per the datasheet blah blah :) : "the total unadjusted error (TUE) is defined as the maximum deviation between the actual and the ideal transfer curves. It is a parameter that specifies the total errors that may occur, causing maximum deviation between the ideal digital output and the actual digital output. It is the maximum deviation recorded between the ideal expected value and the actual value obtained from the ADC for any input voltage." see: <http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/APPLICATION_NOTE/CD00211314.pdf> pag 9, I was considering it the worse case error. > gain error? +-1.5LSB > offset error? +-1.5LSB > integral nonlinearity? +-1.5LSB > What about monotonicity or differential linearity? DNL +-1LSB See : <http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00161566.pdf> pag 76 > > A worst case assumption would be that the ADC is perhaps only > monotonic for the 11 most significant bits. Fabio.

Il 2012-12-28 21:43 Magnus Danielson ha scritto: > The bucket statistic method is very simple. > You divide a scale into a suitable set of ranges, equally wide. The > you count how many "hits" you get within each of those ranges or > "buckets". By the way, since I've seen some contributors that are from Italy (Azelio...? :) what is the correct name of the tecnique in Italian, maybe it's something I've studied or seen somewhere. Thanks. Fabio.