LM5071: flyback transformer design for low power isolated PD

Ben Chen75

Prodigy 250 points

Part Number: LM5071
Other Parts Discussed in Thread: TPS23755EVM-894, TPS23754

Hello,

We are using LM5071 & LM5072-80 for small power (less than 12V/0.8A) design. Due to the mechanical limitation, we

have to use low profile transformer such as Coilcraft's ER14.5. Is there any design tool or workbench so that we can

get design parameters of flyback transformer and pass them to transformer's manufacturer?

Best Regards,

Ben

over 5 years ago

0 Darwin Fernandez over 5 years ago

TI__Mastermind 41790 points

Hi Ben,

I recommend using a known working solution like TPS23755EVM-894 and using that transformer specs. Below is the link. thanks!

0 Ben Chen75 over 5 years ago in reply to Darwin Fernandez

Prodigy 250 points

Hi Darwin,

Thanks for your promptly reply. We already used TPS23754 to design 802.3at products so I believe

that is not a problem to use TPS23754 to design a product referred to "TPS23755EVM-894". The

problem is the flyback transformer implemented in "TPS23755EVM-894" is over the height restriction

of my design. Is there any tool that I can get Transformer's parameters so that I can ask Transformer vender

to design a low profile one?

Best Regards,

Ben

0 Darwin Fernandez over 5 years ago in reply to Ben Chen75

TI__Mastermind 41790 points

Hi Ben,

You can take the transformer specs of TPS23755EVM and ask vendor to fit it into a lower profile. If you want to use a calculator, we don't have a transformer calculator specifically, however I recommend looking at the power stage designer. This way you can choose the power topology, the input voltage range, and output power, and it will give you the transformer spec recommendations for you to test out.

http://www.ti.com/tool/POWERSTAGE-DESIGNER

0 Ben Chen75 over 5 years ago in reply to Darwin Fernandez

Prodigy 250 points

Hi Darwin,

Thanks for your suggestion. I will try it!

Best Regards,

Ben

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LM5071: flyback transformer design for low power isolated PD