PFD cycles desired in ADF4868

Hey Frox, 

I think there is an error on the datasheet. I informed the internal team about this error.

The correct formula should be as follows:

It is taken from the ADF4377 datasheet. 

Thanks,

Emrecan

Hey Frox, 

I think there is an error on the datasheet. I informed the internal team about this error.

The correct formula should be as follows:

It is taken from the ADF4377 datasheet. 

Thanks,

Emrecan

Hi emrecangidik ,

Thanks for the clarification. However I think there is something different in the equation. If you look at the ACE tool (screenshot in the documentation) I cannot reproduce the numbers of LD_COUNT and PFD Cycles

Using fpfd = 245.76MHz, LPBW = 650kHz I get something close to Desired PFD cycles = 559 and therefore LD_COUNT = 10 and not LD_COUNT=12  and 1539 cycles. Am I missing something in the documentation?

Hi Frox, 

I checked the ACE plugin and discovered that ACE assumes the LPBW = 190kHz.

In your calculations, LPBW is 650 kHz, therefore it is expected to have smaller PFD cycles and LD_COUNT as loop filter bandwidth is wider. 

Thanks,

Emrecan

I see, thanks for the clarification