DP83869HM: DP83869HMRGZT RGMII to SGMII mode

ranjini r

Prodigy 150 points

Part Number: DP83869HM

Hii,

I want to use DP83869HMRGZT in SGMII to RGMII bridge mode

What is the recommendation for TD_P/M pins in this mode?

over 4 years ago

0 Kallikuppa Sreenivasa over 4 years ago

TI__Guru**** 190019 points

Hello ranjini r

Thank you for the Query.

If you could provide some additional details on the requirements that would help.

I will assume you are asking what care to take on the SGMII signals.

The SGMII signals need to be AC coupled and have to be placed near to the receiver.

If any of the differential signals have straps, similar dummy straps have to be placed on the other line

Treat them as differential lines during the design.

Regards.

Sreenvasa

0 ranjini r over 4 years ago in reply to Kallikuppa Sreenivasa

Prodigy 150 points

Hi,

Can u please have a look at the attached design & suggest if any changes are to be made?

I have connected 3.3V as VDDIO, does it support the required configuration?ETH_RGMII to SGMII.pdf

0 Kallikuppa Sreenivasa over 4 years ago in reply to ranjini r

TI__Guru**** 190019 points

Hello Ranjini,

Thank you for the inputs. I will review.

Did you not place the AC caps for the SGMII - i did not see them in the schematics.

I have connected 3.3V as VDDIO, does it support the required configuration - please explain what you meant.

Regards,

Sreenivasa

0 ranjini r over 4 years ago in reply to Kallikuppa Sreenivasa

Prodigy 150 points

Hi,

The AC caps are in the other end of schematic.

Regarding the VDDIO voltage - Please ignore that sir.

Regards,

Ranjini

0 Kallikuppa Sreenivasa over 4 years ago in reply to ranjini r

TI__Guru**** 190019 points

Hello Ranjini,

Thanks you for the inputs and no worries.

Please note that the AC caps must be placed near to the receiver - meaning the input caps must be near to the PHY.

I will review and provide my inputs by Wednesday.

Regards,

0 ranjini r over 4 years ago in reply to Kallikuppa Sreenivasa

Prodigy 150 points

Hi Sir,

Surely will take care of the placement of caps.

Thank you

0 Kallikuppa Sreenivasa over 4 years ago in reply to ranjini r

TI__Guru**** 190019 points

Hello Ranjini,

Noted.

Regards,

Sreenivasa

0 Kallikuppa Sreenivasa over 4 years ago in reply to Kallikuppa Sreenivasa

TI__Guru**** 190019 points

7266.ETH_RGMII to SGMII.pdf

Hello Ranjini,

Please find attached.

I assume this a RGMII to 100Base-FX module.

Regards,

Sreenivasa

0 ranjini r over 4 years ago in reply to Kallikuppa Sreenivasa

Prodigy 150 points

Hi Sir,

I wan to use it as SGMII to RGMII bridge

0 Kallikuppa Sreenivasa over 4 years ago in reply to ranjini r

TI__Guru**** 190019 points

Hello Ranjini,

Thank you for letting me know. Looks good.

Regards,

Sreenivasa

0 ranjini r over 4 years ago in reply to Kallikuppa Sreenivasa

Prodigy 150 points

Hello,

Thank you sir. Will implement your feedback.

0 ranjini r over 4 years ago in reply to ranjini r

Prodigy 150 points

Hello,

If you can help, I have a few questions

The termination of unused JTAG signals - to GND?

Adding a parallel 33pF cap - to RBIAS

Only two caps 10uF & 10nF for each supply rail is enough ?

Regards,

Ranjini

0 Kallikuppa Sreenivasa over 4 years ago in reply to ranjini r

TI__Guru**** 190019 points

Hello Ranjini,

Please see below for supply decoupling and JTAG. Place a 33 pF parallel to the RBIAS resistor (R429). This improves device performance specifically during compliance testing.

Regards,

Sreenivasa

0 ranjini r over 4 years ago in reply to Kallikuppa Sreenivasa

Prodigy 150 points

Hello,

Thank you for the inputs.

I'm using 2 DP83869HM. In RGMII to Copper & RGMII to SGMII bridge mode (the feedback points are implemented)

Can you please have a look at the attached design.

Regards,

Ranjini.R7673.ETH.pdf

+1 Kallikuppa Sreenivasa over 4 years ago in reply to ranjini r

TI__Guru**** 190019 points

Hello Ranjini,

Thank for sharing the schematics.

I did a quick review to support the project timeline,

I have embedded the comments in the schematics. Placing a cap between shield and the circuit ground as shown below is recommended. A mounting hole to connect the shield to external ground is also recommended.

4214.ETH.pdf