TPS51120: EMI Issues

alexis fronteau

Part Number: TPS51120

Hi,

I am using a TPS51120 to give a 5V and a 3V3 to my system from an unregulated voltage (12-24V). I observe a lot of electromagnetic disturbances

(radiated for sure, conducted maybe) and it seems that they come from the TPS51120. I think I have followed correctly the datasheet to sizing components,

so is there additional filters (input filter for example) or something to check particularly to reduce disturbances ? I haven't done the routing myself but I don't see

aberrant mistakes. I am using the TPS51120 in current mode, output max 8A, 580Khz for 3.3V an 380khz for 5V.

Thanks

over 5 years ago

0 Sam(MPAA) Zhang over 5 years ago

TI__Mastermind 19080 points

Hi,

Applying an input filter is a good attempt to solve conducted EMI issues.

First of all, is it possible to know, in which frequency range that your design exceeds the limitation in the EMC standard you want to be comply with? Knowing the frequency range is quite important, cause we will take different ways to solve this problem.

Secondly, layout is usually a common source for EMI issues. Can you post your layout here or email it to me? (sam.zhang@ti.com)

Thanks!

Regards,

Hao

0 alexis fronteau over 5 years ago in reply to Sam(MPAA) Zhang

Prodigy 50 points

Hi,

Thanks for your reply,

I have sent you the layout to your email with other explanation.

Thanks,

Power management

Power management forum

TPS51120: EMI Issues