Hi Ryan, It's a little tough to see from the pictures what the "specific phase" is. From your report that all is OK with zero input, I gather it is not at the zero crossing? Is it always at or around the same expected code - even after power cycles and with different sine wave amplitudes, or is it the definitely phase related?
-Francois On Wed, Jan 23, 2013 at 12:11 AM, Ryan Monroe <[email protected]>wrote: > (Looks like casper list does not support attachments. Here are some > links...let's try this again) > http://dl.dropbox.com/u/**2832602/adc2x400_issues_histo.**jpg<http://dl.dropbox.com/u/2832602/adc2x400_issues_histo.jpg> > http://dl.dropbox.com/u/**2832602/adc2x400_issues.jpg<http://dl.dropbox.com/u/2832602/adc2x400_issues.jpg> > > ==============================**================= > Hey guys, > > I'm trying to use the adc2x400-14, a 14-bit ADC part being clocked at 256 > MSPS. > > When I run the adc with zero input, everything looks good. However, if I > put in a sine wave (or anything, really) -- I get this (see figure). Looks > like it has a bunch of outliers. They're not all the same code (see > histogram), but they are coherent with a specific phase of the sine wave > (plus or minus n*pi). > > This happens in both ADC channels, although this figure is just of one. > > Any ideas? Thanks! > -- > > Ryan Monroe > 904.923.8776 > > > -- Francois Kapp Sub-system Manager Digital Back End meerKAT Team founder: Team SKA Africa http://www.facebook.com/Team.SKA.Africa http://teamskaafrica.wordpress.com/ http://www.givengain.com/activist/87536/projects/3987/ SKA South Africa Third Floor The Park Park Road (off Alexandra Road) Pinelands 7405 Western Cape South Africa Latitude: -33.94329 (South); Longitude: 18.48945 (East). (p) +27 (0)21 506 7300 (p) +27 (0)21 506 7360 (direct) (f) +27 (0)21 506 7375 (m) +27 (0)82 787 8407
