TPS23754: Cost Down Design

Kuan Wei Chen (Kevin Chen)

Genius 9710 points

Part Number: TPS23754
Other Parts Discussed in Thread: TPS23751, PMP11254

Dear Team,

If I want to cost down below reference design, do you have any comments?

I can find TPS23754 change to TPS23751 will be a good point, anything else?

Kevin

over 5 years ago

0 Brett Colteaux over 5 years ago

TI__Expert 3700 points

Hi Kevin,

Thank you for your question.

Our PoE applications engineer is looking into your question and will provide you with an update tomorrow.

Best Regards,

Brett Colteaux

PoE Product Marketing Engineer

0 Michael Pahl over 5 years ago

TI__Mastermind 21320 points

Hello Kevin,

Yes changing the TPS23754 to the TPS23751 is a good cost saving step.

If you are looking for a Class 4 10V (down from 12V) design, I would look at the PMP11254.

https://www.ti.com/tool/PMP11254

This design is a diode rectified flyback, it does not have the output inductor nor any electrolytic caps on the output. It also has a smaller input bulk capacitance. You could alter the design to be 10V.

Otherwise the components to look at are the inductor, the FET, the diodes and the transformer.
The key with the diodes is the reverse recovery time and the power levels.

The key with the FET is ensuring the VDS voltage rating and current rating is high enough (usually 150V / 3A).

I would strongly advise NOT changing the transformer since so much of the DCDC is based on the transformer. However, people do it and it probably will have a noticeable cost difference.

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 Gilge over 5 years ago in reply to Michael Pahl

Expert 1720 points

Hello,

we are also using PMP11254 as the basis for a low cost TPS23751 design. We have also changed the transformer against LinkCom LDT8202-51R.

Question: What is the allowable input voltage range for adapter supply? PMP11254 is rather limited form 41 to 57VDC. We would want to get to 24 to 57VDC.

Best regards,

MIchael

0 Michael Pahl over 5 years ago in reply to Michael Gilge

TI__Mastermind 21320 points

Hello Michael,

Per the schematic label on adapter input J5, it can be seen the input voltage range is 41V-57V.

A class 4, 12V output design with adataper voltage 21V-57V is the PM8812.

You can find a full list of our publicly available reference designs on the site:

And you can filter these results.

Lastly, since this was a different question than the original question and a different project, please create a new thread on E2E next time. This helps us keep questions and answers clearly identifiable and searchable.