LM5156H: LM5156H applied circuit review request

Grady Lee

Genius 4165 points

Part Number: LM5156H

Tool/software:

Hi, TI expert

A customer has requested a circuit review of LM5156H applied.

Please check if there are any parts to be modified or added.

7103.POE+SWITCH_SCH_REVIEW.pdf

Please check. Thank you.

6 months ago

0 Moritz 6 months ago

TI__Genius 15545 points

Hi Grady,

Thanks for reaching out.

I can review the schematic. For this i need to know the design specifications (Vin, Vout, Iout).

Also it would be helpful if you can fill out the quickstart calculator for this device. https://www.ti.com/tool/download/SNVC224

Best regards

Moritz

0 KIM JUNG GU 6 months ago

Prodigy 30 points

Hello Moritz,
I will answer your inquiry.
I plan to use it with the following specifications.

Vin : 8 ~ 32V
Typ : 13.2V
Output : 50V, Max 1.2A

I do not know how to link the excel file you sent, so I am attaching the file.

Thank you.

LM5155_56_Quickstart_Calculator_for_Boost_Converter_Design_V1_1_1(DTEG).xlsx

0 Moritz 6 months ago in reply to KIM JUNG GU

TI__Genius 15545 points

Hi Kim,

Thanks for the additional information.

There are many things that are not matching between the values in the calculator compared to the schematic.

I assume that the schematic values are the right ones. Then i have the following points:

- The inductor saturation current is not sufficient. At min Vin, the current will go up to 8A.

- Please check the UVLO resistor divider again. At which voltage you want to stat up/shut down?

- Please check the compensation values again, the design would be unstable with the values used in the schematic.

Best regards

Moritz

0 KIM JUNG GU 6 months ago in reply to Moritz

Prodigy 30 points

Hi Moritz

Thank you for your reply.

I have reviewed the information you sent and rewritten it.

Please check.

Thank you.

Kim.POE SWITCH_SCH_REVIEW(ARROW)_20250218.pdf LM5155_56_Quickstart_Calculator_for_Boost_Converter_Design_V1_1_1(DTEG)_250217.xlsx

0 Moritz 6 months ago in reply to KIM JUNG GU

TI__Genius 15545 points

Hi Kim,

The schematic seems to be good now.

Best regards

Moritz

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LM5156H: LM5156H applied circuit review request