TUSB2036 Unknown Device for all three downstream ports

ROBERT CONWAY

Prodigy 30 points

Having issues with windows not correctly seeing any of the devices attached to the hub.

Windows sees the hub and installed a Generic USB Hub driver.

The three downstream ports all show up as "Unknown Device"

DM/P 1 has a permanent attached device

DM/P 2 has a permanent attached device

DM/P 3 has a pluggable device

Schematic attached if someone would be nice enough to help out.

Thanks

Robert

over 11 years ago

0 Bhaumik Darji over 11 years ago

Intellectual 345 points

Hello Robert,

You have not connected Pull Down resistors on D+/D- for down-stream ports. It may be creating problem. Please see following image.

Warm Regards,

Bhaumik

0 ROBERT CONWAY over 11 years ago in reply to Bhaumik Darji

Prodigy 30 points

Bhaumik,

Thank you for the reply, however I added the 15k pull down resistors and the functionality is the same..

Is there anything we have missed in regard to the configuration of the 2036?

Regards,

Robert

0 Elias Villegas M. over 11 years ago in reply to ROBERT CONWAY

TI__Guru* 76130 points

The edge rate control capacitors are also required on the downstream ports, however I think there is some physical issue, check your connections and layout. Regards,.

0 Bhaumik Darji over 11 years ago in reply to ROBERT CONWAY

Intellectual 345 points

Hi Robert,

Sorry but I do not have any other point which I can suggest you from your schematic snap.

Regards,

Bhaumik

0 ROBERT CONWAY over 11 years ago in reply to Bhaumik Darji

Prodigy 30 points

I found the issue.

The bidirectional TVS we used on J1 and J2 were the problem.

Once I removed these it all started working correctly.

Thanks for the help.

Regards,

Robert

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TUSB2036 Unknown Device for all three downstream ports