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ADC AD9613 pn sequence

Question asked by ARTS on Jun 6, 2014
Latest reply on Jun 6, 2014 by rejeesh

Hi,

I'm using AD9613 ADC (clocked with 150MHz) that is connected to an FPGA. In order to synchronize the data to the FPGA internal clock I need to adjust some delay elements within the FPGA. Since the pn9 sequence is deterministic, it would be a nice way to perform the synchronization using the pseudo random numbers.

However, I'm wondering in which way the pn9 sequence is generated within the ADC. As I understand, the generator polynomial is x^9+x^5+1. If so, which initial value you use in order to get the 12 bits output? I've checked the period of the sequence and it is 511=2^9-1 samples (12 bits per sample) which seems to be correct.

 

I'm using offset binary data format.

 

It would be pretty nice if someone can explain the generation of the pn9 and pn23 sequences and how it is influenced by the chosen data format. It would be helpful to have the table with resulting sequences.


Thanks

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