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Target of "Frequency Stability" plus-minus 50ppm.

Hi,

I have some questions about XTAL frequency specification for ADV devices.

ADV devices have XTAL frequency specification on the datasheets.
For example, ADV748x datasheet says as follows:


Please let me ask a question about the "Frequency Stability" plus-minus 50ppm.

Question:
Is this required specification for only the XTAL IC?
(We have to keep the plus-minus 50ppm for only the XTAL IC?)
Or
Is this required specification for the XTAL IC and the related circuit (including Rdump and C etc.)?
(We have to keep the plus-minus 50ppm for the XTAL IC and including the error/variation of the related circuit (including Rdump and C etc.)?)
Which is correct?

Background:
My customer uses ADV devices (ADV7182A, ADV7282A-M, ADV7611 and ADV7480, etc.)
He uses a XTAL IC keeping the "Frequency Stability" plus-minus 50ppm on the datasheets.
But when considering the related circuit (including Rdump and C etc.), he says the plus-minus 50ppm can not be kept.
The error/variation of the related circuit is plus-minus 25ppm in room temperature, he says.
So we ask these questions.
If the plus-minus 50ppm is required specification for only the XTAL IC, could you tell me the needed "Frequency Stability" for the related circuit (including Rdump and C etc.)?

Thank you!
Best regards.
Tamu