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USB power limits

Posted: Tue Sep 11, 2012 9:11 pm
by redpost
What is the maximum electrical current available on the PC3:
- 2 rear USB 2.0 ports
- 2 rear USB 3.0 ports
- front FACE module 4 USB ports

Re: USB power limits

Posted: Tue Sep 11, 2012 9:17 pm
by redpost
From what I can tell:
- the USB 2.0 specification requires 500mA per bus
- the USB 3.0 specification requires 900mA per bus

So the question is: Are all 4 FACE USB 2.0 ports on one bus? Or do they share the same bus as the 2 rear USB 2.0 ports? I'm assuming the USB 3.0 ports are separate, as they're powered by a separate TI TUSB7320 chip.

Re: USB power limits

Posted: Wed Sep 12, 2012 8:35 pm
by nikkadim
The fit-PC3 Basic, LP and Pro have an additional USB 2.0 4 ports on the front (FACE module), powered by the same controller that powers the rear USB 2.0 ports.

Here's a block diagram for further reference:
http://www.fit-pc.com/IntensePC/docs/In ... iagram.jpg

Re: USB power limits

Posted: Thu Sep 13, 2012 8:08 am
by gabrielh
USB3 has a dedicated USB3 controller, separated from the USB2. Two rear USB2 ports, two front left and two front right have a separate USB2 controller for each pair