Could TPS23861 switching damage Ethernet data interface?

Newton Cardoso

Other Parts Discussed in Thread: TPS23861

Dear TI staff and colleagues,

Has anyone experienced unexpected damage in a Ethernet PHY due to transitions caused by switching on/off a PoE interface?

I am using TPS23861 as PoE controller, and Ethernet interface is shared with a Beaglebone (LAN8710 Microchip Ethernet transceiver). I've noticed that after some on/off commands to PoE circuit, Beaglebone Ethernet stops working.

Any hint?

Best wishes,

Newton

over 9 years ago

0 Penny Xu over 9 years ago

TI__Genius 15685 points

Hi Newton,

To better answer your question, could you please draw a block diagram of your system?

Best regards,

Penny

0 Newton Cardoso over 9 years ago in reply to Penny Xu

Intellectual 745 points

Hello Penny,

I've attached 2 figures. Please notice that SCH_REMOTE_2_00_PoE contains my Ethernet connector J2 connected through cable to Beaglebone's Ethernet connector P5 in figure P09_Ethernet.

Best wishes,

P09_Ethernet.PDF SCH_REMOTE_2_00_PoE.PDF

0 Penny Xu over 9 years ago in reply to Newton Cardoso

TI__Genius 15685 points

Hi Newton,

Your PSE schematic looks good to me. Where's does your 3.3V come from? Our PSE requires a power on sequence. One of the requirements is 3.3V should come after the Vpwr reaches its UVLO(18.5V). We have an app note talking about this: http://www.ti.com/lit/an/slva723/slva723.pdf

the other side of Ethernet cable(receive data)? Does that device need power from the PSE? If it needs the power from PSE side

to do data processing, it should not work when the PSE port is turned off.

What's your power level of your PD and what's the power rating of your data transformer(RJ45)? If the data transformer's power rating is not enough to handle the PD power, I would think the data can't be transmitted successfully.

Best regards,

Penny

Power management

Power management forum

Could TPS23861 switching damage Ethernet data interface?