I have had a look on the Intel Resource and Design Centre and I have also asked Intel support, however, I was unable to find an answer to my question:
What over-current protection is afforded to the external USB 3.0 ports on the NUC7I7DNBE? I ask because I intend to integrate the NUC7I7DNBE into a product which has a sub-system that requires power from at least two USB 3.0 ports (9W total). I intend to use a current-sharing controller to ensure the load is shared between the ports, however, it would be beneficial to know what over-current protection is used so that I can design around it.
Hello fearsome69 ,
Please check the data in Table 25, page 61 of the Technical Product Specification: https://www.intel.com/content/dam/support/us/en/documents/mini-pcs/nuc-kits/NUC7i5DN_TechProdSpec.pd... https://www.intel.com/content/dam/support/us/en/documents/mini-pcs/nuc-kits/NUC7i5DN_TechProdSpec.pd... .
It is defined that the estimated Power Consumption for the four USB 3.0 ports is 20W.
Hope this will help
Thank you for your reply.
I understand that a USB 3.0 port should be able to deliver 4.5W (so ~20W available from 4 ports). I possibly didn't ask the right question: Is there over-current protection on each external USB 3.0 port that limits its power availability? And if so, what is the maximum power which a single USB 3.0 port can deliver? I understand there are current limitations with regards to the connectors and cabling.
In Caution, in para. 2.2 on page 41 of Technical Product Specification you may find the following:
"Only the following connectors and headers have overcurrent protection: back panel USB, front panel USB, and internal USB headers."
So, from this statement, the USB are protected.
Thank you for your reply. Unfortunately, this still doesn't answer my question as it doesn't state how the USB ports are protected. For example:
Yes, you can ask many other questions. For example:
1. How fast will protection trip occur after over-current condition is detected?
2. What will happen with other ports after over-current trip is set?
3. How the protection system is checked?
4. How the system is reset after trip?
I can ask 50 question more. Depends what your needs are. Finally you shall take into consideration that this NUC is equipped with four USB 3.0 ports. Those port are designed and protected according to requirement USB 3.0 specification: https://www.usb3.com/whitepapers/USB%203%200%20(11132008)-final.pdf https://www.usb3.com/whitepapers/USB%203%200%20(11132008)-final.pdf .see para 10.10.1, 10.1.5, 184.108.40.206.1
Hope this helps
Thanks for your reply and linking me to the USB 3.0 specification. I think it is safe to assume that each port is protected and each port can deliver up to 900mA.