Hello,
I'm having some trouble with a TUSB2036 hub on a ground support board I've designed. I have included the schematic sheet with the hub with the modifications I have done so far, along with some scope shots. Hopefully these will answer the first couple rounds of questions I have seen on similar forum posts for assistance with this IC.
The hub is recognized, however, the downstream devices are not functioning properly. The windows machines I have tried all show "this device cannot start" when viewing the individual downstream device properties in the device manager. Though two of the three PCs I've tried running the board from warn that there is a power issue, the board does not consume a lot of power and the supply voltages are all fine. I have removed one of the bulk caps (10uF after the isolated switching supply since I assumed it would cause a significant inrush), but there was no change in behavior. Windows is able to identify the downstream devices (at least the flashdrive is properly identified as a USB mass storage device) before deciding they can't start, so I am having trouble finding a reason that it's not working.
I am aware that the oscillator is missing a series resistor and the downstream USB ports are missing pulldowns. The pulldowns have been haywired and the oscillator appears to be working (exceeding recommended tolerances but within max tolerances).
I would appreciate any insight on why the downstream devices aren't functioning properly. Thanks!
