Hi, we are designing a new USB hub, and I have a question about the #PWR and #OVR pins. If our downstream devices are self powered, is there any problem with bypassing the #PWR and #OVR pins? I am planning to leave the #PWR pins floating and pulling the #OVR pins high with 10k resistors. Will there be any issues with enumeration if the downstream devices are powered up independently of the hub?
There is no issue in enumeration if you don't use the PWR and OVR pins of the hub and have pulled up the OVR pins with a 10K resistor. However it is recommended to connect a power switch to those pins so that the hub can be notified if there is an overcurrent condition on the self powered device.