TUSB8020B: can power be provided from the upstream USB connection?

user5140020

Part Number: TUSB8020B

I'm interested in using this hub for a non-charging application - the expected current draw from the two downstream ports is around 500mA. Is there any issue in tapping off the 5VDC from the upstream port, and regulating it down to 3.3/1.1V for the hub (as well as powering the connected devices)?

Thanks!

over 7 years ago

0 JMMN over 7 years ago

TI__Guru 60870 points

Functionally this will work. If you are building a device that will require a USB compliance logo this application will not pass because the TUSB8020B always reports as a self-powered hub and the TUSB8020B exceeds the low power budget for a bus-powered hub, particularly in the unconfigured and suspend states.

REgards,
JMMN

0 user5140020 over 7 years ago in reply to JMMN

Prodigy 20 points

Thanks JMMN, do you have an alternative product that can be bus-powered and still compliant? For example the TUSB804X?

0 JMMN over 7 years ago in reply to user5140020

TI__Guru 60870 points

Unfortunately, we do not have any USB 3.0 hubs that report as bus powered capable in their USB descriptor set.

Regards,
JMMN

Interface

Interface forum

TUSB8020B: can power be provided from the upstream USB connection?