TUSB8020B: Vendor ID recoganize issue

Hi Len:

   Is this  a new design? or it's a old product with new production devices.

Regards

Brian

Hi Brian,

It's an old design. The part has been used for some time. Can you give some feedback?

Regards,

Len

Hi Len:

     Here are some questions for schematic:

1:  is SMBUS pin grounded?

2:  Can customer take waveform for 3.3v , 1.1v and GRSTz pin at same time?

3:  when issue happens, does  oscillator working?

Regards

Brian

Hi Brian,

Thanks your feedback. 

1. SMBUS is floating. NC means disconnecting.

2.I'll let the customer test the waveform.

3.I'll check and give you feedback.

Besides, this is a probability event. When power cycle, the issue will disappear. Is it possible that some pin connected poor causing this?

Regards,

Len

how often this issue happened? it could be soldering issue ( ground pad)

Can customer find trace lengh for upstream port signals?  maybe e signa; trace too long.

Regards

Brian

Hi Brian,

For the upstream port signal, what's the scale of trace length? We can give them suggestions when they design layout. Thanks.

Regards,

Len