4DSP Support Forum

Products => FMC Products => FMC103, FMC104, FMC107, FMC108 => Topic started by: kjb on July 16, 2014, 12:22 PM

Title: Variable Sampling Frequency for FMC108
Post by: kjb on July 16, 2014, 12:22 PM
Dear 4DSP team,

I hope I am not asking this question unreasoned, but I could not find a definite answer in the FMC108 data sheet nor on the other forum posts.

For our design we consider using the 2 FMC108 card we have at a lower sampling frequency, i.e. 200MSPS instead of 250MSPS. Is this possible with the ADC card. The TI ADS62P49 states explicitely a maximum sampling frequency, hence I should be able to run it at a lower sampling rate. However The FMC108 data sheet only states directly 250MSPS.

Hence my question is: Can I supply an external 200MHz sampling clock to the card without impeding functionality?

Thank you very much in advance,
   Jakob Brunner
Title: Re: Variable Sampling Frequency for FMC108
Post by: arnaudNL on July 18, 2014, 05:16 AM
Dear Sir,


We have not used the FMC108 under such conditions but this should be possible. There might be some firmware rework to be done on the reference design in order to make sure the timing are good when sampling at 200MHz. The default reference design can work on both internal and external clock mode.


Best Regards,
Arnaud







Title: Re: Variable Sampling Frequency for FMC108
Post by: arnaudNL on July 21, 2014, 05:15 AM
Dear Sir,


Can I go ahead and close the topic? I assume the issue is resolved.


Best Regards,
Arnaud
Title: Re: Variable Sampling Frequency for FMC108
Post by: arnaudNL on July 22, 2014, 09:10 AM
This topic is being closed because the issue is considered as resolved by 4DSP. Feel free to create a new topic for any further inquiries.