TPS56C215EVM-762: Cff value

Michael Jeong1

Expert 2600 points

Part Number: TPS56C215EVM-762

Hello Expert,

I wonder about recommended Cff value.

When I checked data sheet, If Vout is 1.2V, Cff is N/A.

But Cff 56pF is applied to EVM.

If used below Vout 1.2V, what is the recommended value? N/A or 56pF?

Also, If you have a bode plot according to R8 and C10 values, could you please share it?

Best Regards,

Michael

6 months ago

0 Calan Elaya 6 months ago

TI__Expert 4285 points

Hi Michael,

The table with recommended component values, Table 8-2, is a table used to help guide the user with recommended components for their design. Cff seems not to be required for Vout 1.2V, but it is included in the EVM because it is recommended for that specific design. With each design varying, you may or may not need the Cff but Cff will help with load transient and other benefits.

I am attaching a few documents on the Bode plot and Cff

Bode document: https://www.ti.com/lit/an/sluaaf4a/sluaaf4a.pdf?ts=1704911198698&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTPS56C215

Cff document: -https://www.ti.com/lit/an/sbva042/sbva042.pdf?ts=1704911238029&ref_url=https%253A%252F%252Fwww.google.com%252F#:~:text=A%20Feedforward%20Capacitor%20Improves%20the%20Load%20Transient&text=In%20other%20words%2C%20an%20ac,%2Dto%2Dpeak%20output%20voltage.

Thank you,

Calan

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TPS56C215EVM-762: Cff value