Hi Jack, Thanks for the reply.
I did not run mmcm calibration. Actually, we checked the ADC by feeding it a low frequency sine wave from a function generator and it works fine. The problem with spikes occurs when we feed the ADC with the photo-detector output. Regards, Sharat On 1 September 2015 at 13:52, Jack Hickish <[email protected]> wrote: > Hi Sharat, > > Are you running the adc mmcm calibration routine after programming your > roach? > > Cheers, > Jack > > On 31 August 2015 at 22:41, sharat varma <[email protected]> wrote: > >> >> Hi Casper, >> >> I am working as a post-doc working under guidance of Dr. Hayden So at The >> University of Hong Kong. >> >> We are using ROACH2 to capture data from optical cytometry. We are using >> ASIAA ADC5G ADC to capture data at 4 to 5 Gsps. >> >> We basically use the following parameters. >> >> Block parameter: two-channel, ZDOK0, demux 1:1 . >> System: roach2, clock source:adc0_clk, clock rate: 300 MHz. >> >> We are connecting the output of a photo-detector 1544-B from Newport Corp >> (the spec is attached) to the ADC input using SMA. >> We find that noisy spikes are introduced when we capture the data through >> the ADC (see attached fig). We double checked if the source had problems >> using a oscilloscope, but on the oscilloscope we do not see any of these >> spikes. >> >> We would be grateful if you could let us know if we are doing anything >> wrong. >> >> Rgards, >> Sharat >> >> >> >
