TUSB 2046BI - Unknown Device/Not Recognized by Windows

Hello,

The connection of RESET# is wrong.

You need to connect it like the below picture.

Regards.

Elias,

Sorry I forgot to mention that I corrected the RESET# pin based on a previous post I found on this forum.  During testing my setup matched what you posted above with R=2.2K and C=0.1uF.  Are those values correct?  If so, any other thoughts on what could be wrong?

Thanks,

Jason

Leave SUSPEND floating.

Everything else looks correct on the schematic.

Check the the crystal is oscillating, reset is high, suspend is low, verify the 1.5K pull-up on DP is connected to 3.3V.

Regards.

I have confirmed that suspend is now left floating.

The crystal starts oscillating, reset is high (with proper delay behind Vcc) and there is a 1.5K pull-up from DP to 3.3V.  However after about 6-7 seconds the suspend output gets triggered and the oscillator shuts off.  I suspect this is due to bus inactivity but I still can't get windows to recognize the hub properly.  Any ideas?

Hello,

SUSPEND going high after a timer is because as you said the hub is not seeing bus activity.

There must be something wrong on your DP/DM lines, can you take some scope captures of DP/DM at the moment when you connect the hub to the host?

Regards.

Attached are 2 screen shots from the O-Scope for the DP0 and DM0 lines.  This occurs shortly after I plug the upstream port into a Windows 7 laptop.  Once screenshot is a big picture of the whole waveform and the second is a close up of the front segment.

Please advise.

On a previous post talking about the Reset# RC circuit you said you have R=2.2K, please change this value to 20K

Regards.

I changed the value to 20k on the reset circuit but kept the cap value at 0.1uF.  I captured new images and they are below.  Please advise.

Any update on this?  I am really stuck and could use the help.

Thanks.

Hello,

I believe you are seeing the pining from the host to the hub, this will happen about every 1ms, some USB host do not put the hub in suspend mode because of this pinging.

Have you tried to connect something downstream the hub?

I would need a protocol capture in order to know if the hub is not responding back to the host.

You can ship your platform to us for debug.

Does the issue go away if you assert/de-assert the Reset# terminal?

Regards.