DP83822I: decoupling cap on TD+, TD-, RD+ and RD- lines

K.Hamamoto

Part Number: DP83822I
Other Parts Discussed in Thread: TIDA-00928

Our customer have some issue about EMI noise on TD+/- and RD+/-. So, they would like to consider to add the decoupling cap on TD+/- and RD+/-.

(Refer post : https://e2e.ti.com/support/interface/ethernet/f/903/p/678290/2521922#2521922

Where should we better to put the decoupling on,

- the side as close as IC

- the side as close as Ether connecter

Which do you recommend?

Best Regards,

Koji Hamamoto

over 7 years ago

0 Geet Modi over 7 years ago

TI__Mastermind 26320 points

Hi Koji-san,

TIDA-00928 DP83822 Reference design meets class B emissions. We suggest customer to review the schematics and layout provided on the site, identify the difference and update accordingly.
Regards,
Geet

0 K.Hamamoto over 7 years ago in reply to Geet Modi

Guru 12155 points

Hi Geet-san,

Thank you for your reply. I understand TIDA-00928 is good reference design. However as Ross-san suggested at previous post (above link), our customer are going to add the decoupling capacitor to TD+/- and RD+/- line. And where we should add that capacitor to IC side or connector side? (This is my question.)

As I can see at the reference,I could not find the capacitor.

Best Regards,
Koji Hamamoto

0 Geet Modi over 7 years ago in reply to K.Hamamoto

TI__Mastermind 26320 points

Hi Koji-san,

I have sent an email, kindly share the schematics again.

Regards,
Geet

0 Geet Modi over 7 years ago in reply to Geet Modi

TI__Mastermind 26320 points

Responded over the email. Closing this thread. Kindly open a new one if needed.

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DP83822I: decoupling cap on TD+, TD-, RD+ and RD- lines