Abstract: A Universal Serial Bus (USB) adaptor (16, 16′, 16″), compatible with standard USB connectors, provides a simplified interface between a portable communications device (12) and a USB accessory (14, 14″). An encoder (28) provides an operating state to the portable communications device (12), enabling the portable communications device (12) to perform as either a USB host or a USB function accessory. A function adaptor (16′) selects its DC power source and is capable of providing DC power to a function accessory (14′). The host adaptor (16) can obtain DC power from a host accessory (14), according to USB standards.

Abstract: A portable communication device (300) powered by a battery (210) has an external connector (202) that includes an external power node (220) and a data bus (204) having an integral power node (218). A processing system (228) of the device senses (402) whether power is available at the external power node, and controls a charging switcher (216) to charge (406) the battery from the external power node whenever power is available at the external power node. The processing system enables (412) battery charging from the integral power node when power is not available at the external power node.