Hi, Ryan, Looks like a setup/hold problem on the input data. Is it coherent with the input sine wave regardless of frequency or do the glitches have the same "period" even for different input frequencies? It almost looks like the glitches happen around the zero crossings which is typically when the most bits change (unless the ADC outputs Gray coding).
You might want to try printing a few successive values in binary before/after one of these glitches. You might be able to determine which bit(s) is (are) "wrong" during a given glitch. It might be that the same few bits are problematic. Dave On Jan 22, 2013, at 2:04 PM, Ryan Monroe wrote: > 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! > <adc2x400_issues.jpg><adc2x400_issues_histo.jpg>
