Patent ID: 7336978

Claim:
A mobile device having an overcurrent cutoff function and at least one function module, the mobile device comprising: a main power supply which supplies power to the mobile device; a power detection unit which detects whether power from the main power supply to the mobile device is cut off, and generates a power cutoff signal when the power is cut off; a backup power supply unit which supplies a backup power to the mobile device when the power from the main power supply to the mobile device is cut off; and a control unit comprises application programs and an operating system, and runs the application programs or controls the at least one function module, and communicates data lines and control signal lines with the at least one function module, and converts potential levels of the data lines and control signal lines connected with the at least one function module to a predetermined potential level in response to the power cutoff signal and then generates a backup power supply enable signal to enable the backup power supply unit to supply power, wherein the control unit further comprises: a flash ROM which stores the application programs to drive the at least one function module; a microprocessor driven by the application programs, and which communicates data with the function module and applies an output power of the backup power supply unit to the mobile device in response to the power cutoff signal; and a level conversion unit which converts the potential levels of the data lines and control signal lines to the predetermined potential level in response to the power cutoff signal.