DP83867E: DP83867ERGZT Magnetic

Yishai Abramov

Part Number: DP83867E
Other Parts Discussed in Thread: TDA4VM, SK-TDA4VM

Hi all,

I'm using DP83867ERGZT ETH PHY in my new design, the Ethernet I/F is not RJ45, I'll be using an Industrial M12 connector for that.

Due to that, I'm not sure about the best suitable Magnetic to use with that chipset.

Please, can be shared a recommended part# that can be suitable to use with those ICs?

Thanks to all,

Yishai,

over 3 years ago

0 Gerome Cacho over 3 years ago

TI__Mastermind 40275 points

Hi Yishai,

Using M12 instead of RJ45 should not be an issue when it comes to magnetic choices. Please ensure that whatever magnetics chosen meets the configuration shown in Figure 27 and specifications in Table 132 in the datasheet. An example that some have used in the past is HX5008NL.

Sincerely,

Gerome

0 Yishai Abramov over 3 years ago in reply to Gerome Cacho

Prodigy 120 points

Hi Gerome,

Thank you for your reply,

Yes, I have read that in the datasheet, I'm confused, I found TIs EVK, which use RJ45 w/Magnetics, and the center tap is sorted to each other internally and 0.1uF capacitor from each center tap to GND.

What is the correct way? from the datasheet "Each center tap on the side connected to the PHY, must be isolated from one another and connected to ground via a decoupling capacitor (0.1 μF recommended)."

Please see the pictures below, the first image, which shows TIs EVK, and the second image of my design.

Thanks in advance

Yishai,

0 Gerome Cacho over 3 years ago in reply to Yishai Abramov

TI__Mastermind 40275 points

Hi Yishai,

Could you please send that link of the EVK design?

All EVMs that I have found either have discrete magnetics (HX5008NL) or integrated magnetics (7499111000A). Regardless of discrete or integrated, I have found that they all followed the same configuration as in the datasheet, which is the official recommendation. Links of some boards that I found:

https://www.ti.com/lit/df/snlr034/snlr034.pdf?ts=1645635590766

https://www.ti.com/lit/ug/snlu176/snlu176.pdf?ts=1645635681237&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FDP83867IRPAP-EVM

Sincerely,

Gerome

0 Yishai Abramov over 3 years ago in reply to Gerome Cacho

Prodigy 120 points

Hi Gerome,

Thank you for the links,

Yes, the TIs EVK is the "SK-TDA4VM - TDA4VM processor kit for Edge AI vision systems" on page 31, you can see the ETH PHY implementation.

Please see the link >> https://www.ti.com/tool/SK-TDA4VM

Regards,

Yishai,

0 Yishai Abramov over 3 years ago in reply to Yishai Abramov

Prodigy 120 points

I have fixed my design accordingly, but yet, I have left the short option w/resistors as not populated, you can review it?

Thank you,

Yishai,

0 Gerome Cacho over 3 years ago in reply to Yishai Abramov

TI__Mastermind 40275 points

Hi Yishal,

Thank you for letting me know about the EVK design.

Regarding your design, please upload the schematic and I will review it. Please note that schematic reviews may take up to 5 working day turnaround.

Sincerely,

Gerome

0 Yishai Abramov over 3 years ago in reply to Gerome Cacho

Prodigy 120 points

Hi Gerome

Thank you, I have attached the schematic section of the 1G ETH PHY

Have a nice weekend,

Yishai,

0 Gerome Cacho over 3 years ago in reply to Yishai Abramov

TI__Mastermind 40275 points

Hi Yishal,

Thank you for the .pdf. I look to have feedback out by EoD Wednesday.

Sincerely,

Gerome

+1 Gerome Cacho over 3 years ago in reply to Gerome Cacho

TI__Mastermind 40275 points

Hi Yishai,

My feedback:

- Please follow decoupling scheme for power pins as listed in the datasheet

- Change R49 to 4.7nF

- Change R198 to 11k 1% tolerance

- Ensure crystal meets specs within the datasheet. Can measure clock out to verify signal

- Ensure no PU resistor on MDC, but 1.5-2.2k PU resistor on MDIO

- Ensure Reset_N is high during normal operation

- It appears you have DNP'ed it, but ensure there is no termination circuitry between P and N on MDI channels

- Strapping. I have deciphered the following settings:

+ PHY Address 0x2

+ Autonegotiation enabled

+ RGMII TX/RX Clk Skew at 2ns

+ Autonegotiation advertised for 10/100/1G

+ Mirror mode disabled, SGMII disabled

Sincerely,

Gerome

0 Yishai Abramov over 3 years ago in reply to Gerome Cacho

Prodigy 120 points

Hi Gerome,

Thank you for the feedback and the SCH review. Sorry for the delayed reply.

Regards,

Yishai,

0 David Creger over 3 years ago in reply to Yishai Abramov

TI__Mastermind 27212 points

Hi Yishai,

Let us know if you have additional questions. Otherwise I will close this thread.

Thanks,

David

0 Yishai Abramov over 3 years ago in reply to David Creger

Prodigy 120 points

Hi David,

The questions were answered,

Thank you,

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DP83867E: DP83867ERGZT Magnetic