I'm trying to add power control to a USB hub based on the Terminus Tech FE1.1s hub chip. From the datasheet, I know the chip supports ganged power control, so all ports share a single switch. That's fine for me, I'm actually planning to use the switch to control only one of the four downstream ports the hub has.
As far as I understand the datasheet, the PWRJ pin (pin 25) is a digital output pin that outputs low (<0.4V) for when power should be enabled, and high (>2.4V) when it's disabled. These levels are at 4mA.
I'm now trying to figure out what kind of transistor (and accompanying resistor) I need to use for switching the power of one of the hub's USB ports with the output of the PWRJ pin. The consumer at that port (soldered in) could theoretically draw 500mA, but in reality, I believe even 100mA could be enough.
I'm a beginner when it comes to electronics, and I still find the range of transistors rather complex. I believe I need an NPN transistor (since low should enable power), and in order to get minimal voltage loss (USB needs its ~5 Volts), I probably need a MOSFET?
What transistor could fit my requirements here? What characteristics do I have to look for?
Any help is highly appreciated!