LM5175: LM5175 waveform unstable in 3A

Hi Kami,

Thank you for considering the LM5175.  The waveform does not look stable.  I tried the design tool and found your loop compensation network was quick different from the design tool recommendation. Please recheck.

www.ti.com/.../lm5175quickstart-calc

Also the schematic is not complete and a good review is not feasible.  Just for the portion of the schematic that you showed, it is not clear how did you separate the PGND and AGND nodes, and I don't see a bulk capacitor at the output, which may be needed for damping of the output LC filter (main inductor and the output capacitor).

Please refer to the calculator and make some adjustment in accordance and see if the issue can be resolved.  Please let us know the result.

Thanks,

Youhao Xi, Applications Engineering

Hello Youhao,

The customer gave me the entire schematic, so I could not disclose it on e2e. Can you give me an email? I can email the customer's schematic to you, please help us review.

Best Regards,

Kami Huang

Hi Kami,

I have send the connection request through PMS, please accept and send me your schematic.

Lets close this thread here and continue the discussion through PMS.

Thanks,

Youhao

Hello Youhao,

I don't not receive you PMS. Would you please accept my friend invitation .

Best Regards,

Kami Huang