TPS54A20: TPS54A20 Cff and internal configuration question?

There are some changes in progress to this datasheet.  The internal details are complicated.  Please contact me directly.

Dear John Tucker,

Thank you very much for reply.

I sent question to your private E-mail address.

Best regard.
Bob Lee.

Hi Bob,

There is a training video series that explains how the converter works and how to select the component values, including Cff. You can find that training here: https://training.ti.com/designing-tis-series-capacitor-buck-converter 

Dear Pradeep Shenoy,

Thank you very much for reply.

I sent question to John Tucker private E-mail address as well.

I saw Training presentaion.

Although the calculation formula of Cff was stated,
Can you calculate from Fz?

Althought I think that calculation Fz = 1 / (2π × R1 × C1),
Can you calculate C1 from here?

Is there a fixed frequency of Fz in TPS54A20?

Best regard.
Bob Lee.

Dear JohnTucker,

Could you teach progress situation?

Best regard.
Bob Lee.