DP83849I: Extender mode

Hirotaka Matsumoto

Part Number: DP83849I

Hi all

Would you mind if we ask DP83849I?
Our customer would like to configure the attachment file's configuration using DP83849I with Extender mode.
20200122_DP83849I.pdf

Is it possible?
As the background of this question, our customer would like to use DP83849I with Extender mode for equalizer.
If the board layout of DP83848 is enought, there is no trouble.
However, theire board layout is not good, so they could not pass the compliacnce test.
Therefore, they intend to use DP83849I with Extender mode for equalizer.

Kind regards,

Hirotaka Matsumoto

over 4 years ago

0 Vibhu Vanjari over 4 years ago

TI__Genius 11900 points

Hello Hirotaka-san,

Yes the DP83849 can be configured in extender mode. This document: http://www.ti.com/lit/an/snla086b/snla086b.pdf provides more information regarding this use case.

Thanks,

Vibhu

0 Hirotaka Matsumoto over 4 years ago in reply to Vibhu Vanjari

Guru 27525 points

Vibhu san

Thank you so much for your reply!

We would like to confirm one point.
On our attachment file, which <Pattern1> or <Pattern2> are the better?

Kind regards,

Hirotaka Matsumoto

0 Vibhu Vanjari over 4 years ago in reply to Hirotaka Matsumoto

TI__Genius 11900 points

Hello Hirotaka-san,

Pattern 1 is will be more useful in extender mode, because now you have two cables between the PHYs instead of one, maybe twice the distance.

Both are possible. Pattern 2 can be used as well but you will need to ensure that no DC voltage is transmitted.

Thanks,

Vibhu

0 Hirotaka Matsumoto over 4 years ago in reply to Vibhu Vanjari

Guru 27525 points

Vibhu san

Thank you so much for your prompt reply.

Both are possible. Pattern 2 can be used as well but you will need to ensure that no DC voltage is transmitted.
->In this case, AC coupling caps require between the other TD and the other RD, right?

And then, on Eternal Board of our attachmentfile, we assume that CPU doesn't require to configure extender mode because we should use BootStrap.
Is our recognition correct?

Kind regards,

Hirotaka Matsumoto

0 Hirotaka Matsumoto over 4 years ago in reply to Vibhu Vanjari

Guru 27525 points

Vibhu san

We assume that your days are so busy.
If you have some update for our last reply, could you let us know?

Kind regards,

Hirotaka Matsumoto

0 Vibhu Vanjari over 4 years ago in reply to Hirotaka Matsumoto

TI__Genius 11900 points

Hello Hirotaka-san,

Yes you will need AC coupling caps.

Please see "5.4.4.4 Strapped Extender Mode" for extender mode, yes you can configure it with strap pins.

Thanks,

Vibhu

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DP83849I: Extender mode