Mobile phones with USB OTG are not uncommon today. I am wondering that how can a battery operated device like mobile phone power a pen drive? From what I know, the power consumption of pen drive on 5V VBUS is around 100mA. The 5V can be derived from the battery voltage using boost converters, but are these converters so efficient and offer such a high current?
This question came to my mind when I came across a topic "connecting a pen drive to my android phone" when browsing for USB OTG.