DP83848K: TD+/TD- pin waveform difference

Satoshi

Guru 19645 points

Part Number: DP83848K

About DP83848K, measured TD+(16 pin) and TD-(14 pin) by differential probe.

These waveform ware not smoothed, but competitor is smoothed on the same condition, waveform is attached.

（100Mbps is no problem(clean waveform), 10Mbps is only no-smoothed.）

・DP83848K

・Competitor

I think that the reason is below, is it correct? If there the other possibility of reason, please let me know.

・Is DP83848K become these waveform on the condition of 10Mbps by internal circuit?

・Cable length is 20cm~1m. Is very short length cable influence any problem to DP83848K?

Best regards,

Satoshi

over 7 years ago

0 Satoshi over 7 years ago

Guru 19645 points

Any update on this?
I think that additional possibility is matching for Transformer.

Best regards,
Satoshi

0 Aniruddha Khadye over 7 years ago in reply to Satoshi

TI__Mastermind 18425 points

Hello Satoshi,

Is customer forcing the speed on DP83848K and connecting a 100ohm differential load for doing this measurement?
You are correct in suspecting that the transformer might cause this, components on the line driver side can have impact on the output waveform. Is customer facing communication issues because of this?

-Regards,
Aniruddha

0 Satoshi over 7 years ago in reply to Aniruddha Khadye

Guru 19645 points

Aniruddha-san

Thank you for reply,

I confirming to customer about forcing speed and differential load.
I will feedback to you if customer any update.

Waveform is not smoothed, but communication is fine.

Best regards,
Satoshi

Interface

Interface forum

DP83848K: TD+/TD- pin waveform difference