Hi, Tom, Have you calculated the skewness for some largish number of samples or are you just going by the appearance of the histogram? If the latter, are you sure that the apparent skewness is not due to artifacts from the histogram bin limits vs discrete sample values?
If you swap ADCs, does the same input signal show the same skewness? Just some ideas, Dave On Apr 24, 2015, at 5:38 PM, Kuiper, Thomas (3266) wrote: > Thanks, Dan. Yes, we're using KAT ADCs. I'm not worried about a DC offset > and I know about the slight ADC bias. It's the skewness I'm wondering about. > It's just barely detectable by eye in a histogram. > > Tom > ________________________________________ > From: dan.werthi...@gmail.com [dan.werthi...@gmail.com] on behalf of Dan > Werthimer [d...@ssl.berkeley.edu] > Sent: Friday, April 24, 2015 5:34 PM > To: Kuiper, Thomas (3266) > Cc: G Jones; Casper Lists > Subject: Re: [casper] Skewed data samples > > hi tom, > > if you are using casper adcs: > > all the casper adc boards are AC coupled > (they have baluns and coupling capacitors), > so even if your input signal has a DC offset, it won't couple > into the ADC. however, there are slight DC offsets in the ADC, > so there will be a small spike in the DC bin, but probably > not from the signal your are injecting. > > best wishes, > > dan >
