SpecificationsOperating Voltage 5V USB Controller MAX3421E Max Current 500mA when Arduino is powered by a suitable power supply connected to the Arduino power jack Max Current 400mA when Arduino is powered by its USB port
The Arduino USB Host Shield allows you to connect a USB device to your Arduino board. The Arduino USB Host Shield is based on the MAX3421E , which is a USB peripheralhost controller containing the digital logic and analog circuitry necessary to implement a full-speed USB peripheral or a full-low-speed host compliant to USB specification rev 2.0. The shield is TinkerKit compatible, which means you can quickly create projects by plugging TinkerKit modules onto the board.