Patent ID: 7028126

Claim:
A Mobile computing device that can be configured to operate both as a USB host or a USB device comprising: a processor, wherein an operating system of the mobile computing device instructs the processor to operate as a USB controller and the USB controller can be configured to operate as a USB host or a USB device and the processor is operationally coupled to a first power conversion circuit in the mobile computing device; a housing having an expansion module bay for receiving an expansion module that includes a circuit for providing an expansion module function including a game card and/or a modem functionality; wherein the expansion module is operationally coupled to the mobile computing device via a first USB connector in the expansion module and a second USB connector positioned in the housing to mate with the first USB connector; and the circuit interfaces with a USB interface and a second power conversion circuit, which is coupled between the USB interface and the first USB connector in the expansion module; and the first and second USB connectors have a form factor that is different than a standard USB form factor; and at any given time only the first power conversion circuit or the second power conversion circuit performs power conversion specified by convention, wherein the expansion module can be configured as a USB device by using the USB interface having a USB bus interface and a layer that handles routing data between the bus interface and plural endpoint; wherein the second power conversion circuit includes a voltage sensor for sensing a voltage signal on the first USB connector and the sensed voltage signal is supplied to a controller of the first power conversion circuit that determines whether the sensed voltage signal should be boosted, reduced or passed through and if the sensed voltage signal is to be boosted, then the controller commands a first switch to send the sensed voltage signal to a charge pump that provides a boosted voltage to a second switch.