USB bus powered hub - more than 100 mA per device?
I have designed a board around that hub.

In my application, it was allowing access to a FT232 and a FT245.

If everything is on your own PCB, I would recommended you just completely ignore the entire overcurrent protection systems entirely. After all, if something on your PCB fails, the whole thing will need work, so making the device able to handle a partial failure is kind of a moot point.

In my situation, I strapped the TUSB to request the full 500 ma and disable the overcurrent protection, and just ran everything straight from the USB 5.0v. I accomplished this by forcing the hub to report as self-powered to the upstream host.

I have made a couple of the boards, without any real problems, so it seems a perfectly workable strategy. It's also been used with several different computers, so I'd feel pretty confident using it as-is. 

Of course, if this is for a production device, rather then a personal project, or a test-harness (which is what it is in my case), it's a whole different problem.



(See the note on the schematic)



For what it's worth, you can often pretty horribly abuse most modern USB ports without too much trouble. A lot of them can supply far more power then the 500ma they are rated for, without too much trouble.
Also, most of them (all I have tested, barring some laptops) will happily supply the full 500ma without a device having to enumerate at all.

However, this varies from motherboard to motherboard, depending on how the USB host is designed. Your mileage may vary.