The TUSB4020BI of Texas Instruments is a dual port USB 2.0 hub. When power is required for any port, the group hub switches the power to all its downstream ports. The downstream ports are not powered off unless all ports are in a state that allows power to be lost. In addition, when a hub senses an overcurrent event, power to all downstream ports will be cut off.
They provide USB high-speed/full speed connectivity on the upstream ports and high-speed, full speed, or low-speed connectivity on two downstream ports. When the upstream port is connected to an electrical environment that supports high-speed and full/low speed connections, enable high-speed and full/low speed USB connections on the downstream port. When the upstream port is connected to an electrical environment that only supports full/low speed connections, the high-speed connection on the downstream port is disabled.
The TUSB4020BI supports each port or combined power switch and overcurrent protection. Each port power control hub switch power is required to turn on or off the USB host to each downstream port. In addition, when a single port power control hub senses an overcurrent event, only the power of the affected downstream port will be shut down.
