TPS54335AEVM-010: Phase Margin is too low issue.

Jerry Chu

Genius 4915 points

Part Number: TPS54335AEVM-010
Other Parts Discussed in Thread: LM25011, TPS54335A

Hi Expert,

If I used EVM Comp value to Webench, the Webench will show the error message. Which one is correct? Thanks!

0 Shawn Nie over 4 years ago

Hi Jerry,

The values of compensation is related to the VIN, Vout and Cout, when these values are changed, the compensation values also need to be changed.

Shawn

0 Jerry Chu over 4 years ago in reply to Shawn Nie

Genius 4915 points

Hi Shawn,

Yes! But I follow TI EVM condition to do the Webench. It confused me.

0 Shawn Nie over 4 years ago in reply to Jerry Chu

Hi Jerry,

If you configure all the parameters as TPS54335AEVM, there is no issue.

Shawn

0 Jerry Chu over 4 years ago in reply to Shawn Nie

Genius 4915 points

Hi Shawn,

I am not sure what's wrong. But the link is for LM25011. Could you help it again? Thanks!

0 Shawn Nie over 4 years ago in reply to Jerry Chu

Hi Jerry,

It is TPS54335A when I open the link.

All right, please configure the schematic as below picture, the phase margin is enough.

0 Jerry Chu over 4 years ago in reply to Shawn Nie

Genius 4915 points

Hi Shawn,

That's weird, you can see my report show the phase margin is too low.

0 Shawn Nie over 4 years ago in reply to Jerry Chu

Hi ,

The phase margin is 67C for your report.

For the "Design Alerts: Phase margin is too low", maybe it is not the updated information, I don't know how it happened.

For double check, you can simulate the bode plot, not just concern the "Design Alerts".

Shawn

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