TPS23754: SCH review

Amelie Zheng

Genius 10865 points

Part Number: TPS23754

Hi Team,

May I ask whether you could help to review customer's POE design?

SCHEMATIC1 _ P14_1_1POE.pdf

over 3 years ago

0 Michael Pahl over 3 years ago

TI__Mastermind 21320 points

Hello,

Currently the apps team is heavy on apps support, we may have comments early next week. However, if this is more urgent, can you help compare customer schematic with the TPS23754 EVM and let us know the differences? This way we can close the review sooner. Thanks!

If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

Regards,

Michael P.

Applications Engineer

Texas Instruments

0 Michael Pahl over 3 years ago in reply to Michael Pahl

TI__Mastermind 21320 points

Hello Amelie,

The schematic looks like a complete copy of the EVM for the most part. The only big difference is the 22uF cap on VC and the output 100uF Cap. These are ceramic in the customer design. I would increase the 22uF cap to 47uF if the customer must stay with ceramic, or change it to electrolytic.

The 100uF cap helps set the dominant pole and zero in the feedback control. The dominant zero is based on the ESR - so when the cap is switched to ceramic, it eliminates that zero. So the feedback loop will need to be adjusted.