DP83869HM: Request for Circuit Diagram Review

WOOHYUN NAM

Prodigy 200 points

Part Number: DP83869HM
Other Parts Discussed in Thread: DP83869

We wish to verify whether there are any issues with the circuit diagram.

6 months ago

0 David (ASIC) Liu 6 months ago

TI__Guru**** 190811 points

Hi,

Which functional mode are you trying to implement with this design?

Can you also share the connection to the transformer and RJ45 receptacle?

You can also use the attached schematic checklist to check against your design.

snlr051c.zip

Thanks

David

0 WOOHYUN NAM 6 months ago in reply to David (ASIC) Liu

Prodigy 200 points

Connection structure shared.
When setting ETH_RXD3 to “0” in the mode settings, should the R197 resistor be left in the OPEN state? (Is it acceptable not to connect the pull-down resistor?)

We plan to verify the detailed mode settings via the software.

260109_ Circuit DR V4A EX TI_V1 EX.pptx

0 David (ASIC) Liu 6 months ago in reply to WOOHYUN NAM

TI__Guru**** 190811 points

Hi,

It looks like this is a RGMII to Copper Mode design. For RGMII to Copper Mode,

RX_CLK is not used, so you can leave it floating
RX_CTRL controls port mirroring. You can leave it floating to disable port mirroring, or pull it high using 2.49k to enable port mirroring.
RX_D2 and RX_D3 can both be left floating since they have internal pulldown.

I am also concerned that DP83869 MDI output is connected to the transformer/RJ45 receptacle through a FFC cable. The FFC cable typically is not shielded so the EMI performance is poor, and its crosstalk performance is poor which would affect signal integrity. I would place DP83869, transformer, and RJ45 on the same PCB instead using the FFC cable.

Thanks

David

0 WOOHYUN NAM 5 months ago in reply to David (ASIC) Liu

Prodigy 200 points

Hello
I've compiled a pin-specific checklist and am sharing it.
Please review it.

DP83869_Schematic_Checklist_RevC (public) SL2.xlsx

+1 J 5 months ago in reply to WOOHYUN NAM

TI__Mastermind 26771 points

Hi Woohyun,

The schematic checklist and the schematic looks good.

Best,
J

Interface

Interface forum

DP83869HM: Request for Circuit Diagram Review