TUSB4020BI: TUSB4020- Hub not detecting in some laptop

Nitesh,

We are currently working on your issue and will reply as soon as possible.

Hi Malik,

Thanks for the update, we are @ very critical phase of the project(final release to Market), i would appreciate if you are give the update by this week end.

Thanks in advance

Nitesh

Nitesh,

We will need a schematic and if you can load the usbview.exe tool from Microsoft and send a screen capture of what it reports when the error occurs that will be very helpful. Also, any information on the failing platforms would be helpful too.

Regards,
JMMN

Hi JMMN,

Thanks for the support, I will get back to you with details as you requested, Give me one or two days of time.

Thanks again,

Nitesh

Hi JMMN,

Attached logs and schematics for your reference

Data_Capture.zip

 Schematic:

USB_Part.pdf

Please do the needful,

Thanks in advance

Nitesh

Hi Nitesh,

This doesn't look like an issue with the TUSB4020B, it looks like an issue with the BQ24392. Can you check the outputs of the BQ24392 control lines when the failure occurs?

Regards,
JMMN

Hi JMMN,

Thanks for the quick analysis, by the way if we connect the USB 3.0 Hub to Laptop and connect our product ( i.e. TUSB4020B) it works fine. So still the issue is in BQ24392?

Please confirm. I will share the BQ24392 output analysis in my next reply.

Thanks in advance,

Nitesh

Hi Nitesh,

Yes, the BQ24392 has the ability to disconnect the hub from the host under certain conditions and that is the likely cause. Connecting the hub to another hub and then the host can change the bus behavior and thus affect the BQ24392. Please provide the line states so we can confirm.

Thanks!
JMMN

Hi JMMN,

I understand, i have captured the two waveform one with working laptop and another with non working laptop,

Attached both for your reference

Working One......

Ch1 is D- and Ch2 is D+ line @ BQ24392 IC input, Similar waveform observed @ BQ24392 IC output D- and D+ which connected to HUB IC

Non Working .....

Please let us know any further analysis is required.

Thanks in advance

Nitesh

Hi Nitesh,

Can you send me the outputs of the BQ24392 (CHG_AL_N, CHG_DET and SW_OPEN)? It does look like the BQ24392 is doing some sore of battery charging handshake that is impacting USB.

Regards,
JMMN

Hi JMMN,

Once i am back in office on monday i will share the signal levels to you.

Thanks in advance

Nitesh