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 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 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
>>
>>
>>
>
