Data Sheet

7
Self-Power Mode
If you connect the power supply to the micro USB port (power in) on the USB hub, the
USB hub will work in self-power mode, or say it becomes a powered USB hub. In this
case the maximum output current for all USB ports are 2,600mA.
If the USB hub is also back-powering your Raspberry Pi, the current consumed by
Raspberry Pi is also taken into account. For example, if Raspberry Pi consumes
260mA, then the maximum output current for all USB ports will become 2,340mA.
About MTT and STT
A USB hub may have two possible ways for organizing Transaction Translators (TTs).
A USB hub could have one TT for all downstream ports that have USB devices
attached (which is called Single Transaction Translator, STT), or the USB hub could
have one TT for each downstream port (which is called Multiple Transaction
Translator, MTT) .
For Single Transaction Translator (STT), connecting one USB 1.1 device to the hub
will force all ports to process data with USB 1.1 standard, thus slowing down all USB
devices on the same USB hub. While for Multiple Transaction Translator (MTT), each
downstream port has its own transaction translator to provide the best USB
performance no matter what class of USB device is connected.
So MTT is better than STT, if the higher price is acceptable.
This USB hub has Multiple Transaction Translator (MTT).