TPS568236: WEBENCH FCCM mode with 220pF Cff

Noah Hicks

Part Number: TPS568236

Tool/software: WEBENCH

Hi, I'm trying to simulate the TPS568236 in FCCM mode with a 220pF feed forward cap, but when I select FCCM mode, it automatically makes the Cff 22 pF. Then when I make it 220pF, it makes the control mode ECO again. Wondering if this is a requirement of the part, or a bug with WEBENCH.

Here's a link to my design: webench.ti.com/.../SDP.cgi

over 1 year ago

0 Savith Kumar Rayakanti over 1 year ago

TI__Expert 5740 points

Hi Noah

Did you try to manually change the Cff value?

I did change the the cff value manually and the design able to simulate with 220pF in FCCM

WBDesign17_Startup-2.pdf

1. click on the component and choose alternate part and change the range for values you want to use

0 Noah Hicks over 1 year ago in reply to Savith Kumar Rayakanti

TI__Prodigy 110 points

Hi Savith,

By changing the value manually do you just mean clicking on the component and switching to a 220pF cap? I have tried this.

If it makes a difference I'm using a 2.2uH inductor. Simulating in WEBENCH isn't a big deal, just wanted to make sure the part was compatible with these external components.

0 Savith Kumar Rayakanti over 1 year ago in reply to Noah Hicks

TI__Expert 5740 points

Noah,

We Guarantee what is mentioned on the datasheet for the part TPS568236

and if you find any inconsistency with webench pls do let me know so that I can report this to webench team

Thank you

Savith

Power management

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TPS568236: WEBENCH FCCM mode with 220pF Cff