LM5155-Q1: PSR flyback design calculation

Haiwen Huang

Part Number: LM5155-Q1
Other Parts Discussed in Thread: LM5155, LM5157

Tool/software:

Dears:

customer want to use LM5155 do PSR flyback , they need TI help provide PSR design calculation then they can design it step by step .

I noticed that we have <<How to Design an Isolated Flyback Using the LM5155>> application note, but it's for secondary feedback solution. Thanks.

0 Moritz 1 month ago

Hi Haiwen,

Thanks for reaching out.

Besides the App note <<How to Design an Isolated Flyback Using the LM5155>> i can recommend these two:

Also they can use our quickstart calculator for PSR design: https://www.ti.com/tool/download/SNVC240

Best regards

Moritz

0 Haiwen Huang 1 month ago in reply to Moritz

Hi Moritz::

This calculator is for secondary flyback design. Do you have PSR version ? Thanks.,

Moritz said:
Also they can use our quickstart calculator for PSR design: https://www.ti.com/tool/download/SNVC240

0 Moritz 1 month ago in reply to Haiwen Huang

Hi Haiwen,

You are right, the PSR calculating option is in the LM5157 calculator: https://www.ti.com/tool/download/SNVR508

For the calculation of the Aux winding you can also use this one.

Or the calculation for the Aux winding is done by hand, it is the same like for the secondary winding.

Best regards

Moritz

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