DP83867IR RBIAS

Vincent GROUHEL

Prodigy 10 points

Hello,

We made a board using DP83867IRPAP in two power supply mode.

Our power sequence is 1.1V => 1.8V 5ms delay (VDDIO) => 2.5V.

On first batch, some board work and others not.

Power supply is ok on all board. Rbias is 11k on all board.

The voltage on rbias is different on board that don't work: around 150mV or 1.4V.

Can you provide more information on how this pin work ?

Best regards

over 9 years ago

0 Rob Rodrigues over 9 years ago

TI__Mastermind 19780 points

Hello Vincent,

There is a voltage reference inside of the PHY that sets up a known current through the RBIAS resistor. This voltage reference is enabled automatically.

Can you provide a schematic of your boards for us to review?

Best Regards,

0 masahiko shimizu over 8 years ago in reply to Rob Rodrigues

Guru 11235 points

Hi Rob-san,

I wants to know about RBIAS, too.

Is the setting of RBIAS related to driving current value of TD_x_x pin?

Best regards,

Shimizu

0 Ross Pimentel over 8 years ago in reply to masahiko shimizu

TI__Mastermind 23675 points

Hi Shimizu,

RBIAS will affect the gain of the analog portion of our PHY.
If you increase the resistance of RBIAS, the gain will reduce and visa versa.

Best regards,
Ross

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DP83867IR RBIAS