USB hardware - Wikipedia USB 3.x and USB 1.x Type-A plugs and receptacles are designed to interoperate. To achieve USB 3.0's SuperSpeed (and SuperSpeed+ for USB 3.1 Gen 2), 5 extra pins are added to the unused area of the original 4 pin USB 1.0 design, making USB 3.0 Type-A plugs and receptacles backward compatible to those of USB 1.0. Related searches for usb schematic design usb schematic diagramusb power schematicmicro usb schematicusb circuit schematicusb port schematicsignalink usb schematic diagram