Offtopic? USB HASP

[dedificator]

Info for some clarity in USB devices powering scheme. Power management must be done through datalines (connecting some specific load, while power-up the device). By this way USB host (PC) knows device power requirements. This isn't done by USB chip, but using external circuit (often NPN transistor and pair of resistors). This circuit CAN burn-out, if wrong timings or components are used, not USB chip itself .... There is only one possiblity for overpowering - 5.2V or greater voltage from PC power supply. In case of dongles there are big problems with space and component placing on PCB, so many simplifications are used, ignoring full USB specifications ...