TPS2372: Ethernet packet loss issue

Vickers

Part Number: TPS2372

Hello,

When we use the TPS2372 POE to supply power, there will be packet loss when the network cable is 100 meters ping packet test.

When we switch to DC24V, it is normal.

over 6 years ago

0 Darwin Fernandez over 6 years ago

TI__Mastermind 41760 points

Hi Vickers,

You may want to check your PoE PD front end filtering and layout. Usually there is an EMI filter after the diode bridge to reduce the noise from the DCDC converter to the data transformer. Do you have a schematic we can review? Thanks!

0 Thomas Lewis over 6 years ago in reply to Darwin Fernandez

TI__Expert 5615 points

Vickers,

It has been ~ 1 week since you have corresponded with us. As such, we are going to consider this matter resolved and close the thread.

Please reply if that is not accurate (a reply with automatically re-open the thread).

Thanks,

0 Vickers over 6 years ago in reply to Thomas Lewis

Intellectual 980 points

Hello Darwin and Thomas,

Sorry for the late response.

Attachment is schematic.Pls help to review it.

As below is not welding:

8030.原理图检查.pdf

0 Darwin Fernandez over 6 years ago in reply to Vickers

TI__Mastermind 41760 points

Hi Vickers,

I don't see in the data transformer (U5) datasheet that it can handle PoE? Can you check with your transformer vendor?

If it can handle poe power, a couple of things catch my eye on the schematic that might affect the data:

The bob smith terminations should be 0.01uF (C21,20,95,96).
There is usually a filter after the diode bridge (similar to the TPS2372EVM).

0 Vickers over 5 years ago in reply to Darwin Fernandez

Intellectual 980 points

Hi Darwin,

Any difference with the transformer?

Customer also uses this transformer in the at/af project. Test only use 30w power, DC24V power supply is normal.

0 Darwin Fernandez over 5 years ago in reply to Vickers

TI__Mastermind 41760 points

Hi Vickers,

I'm not too familiar with the data side of PoE as I focus on PoE power. So the above ping information data I'm not sure about.

Have you tried adding the EMI filter after the bridge (maybe a choke or ferrite boards)? It might be working with the 30W design but for higher power levels, the noise will increase (which will also depend on the layout of the board). Also, is the data transformer rated for .bt power levels?

Also have you tested my bob smith termination values?

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TPS2372: Ethernet packet loss issue