Electronic device with connection interface supporting signal communication and charging operation

An electronic system comprising:

• a power supply device comprising:
• a first connection interface;
• a control unit coupled to the first connection interface;
• and
• a power switching unit, coupled to the first connection interface and controlled by the control unit, for selectively providing a first supply voltage or a second supply voltage;
• and
• an electronic device being capable of being powered by the power supply device, wherein the electronic device comprises:
• a second connection interface comprising a power pin and a signal transmitting/receiving (T/R) pin set;
• a voltage regulation unit coupled to the power pin;
• a storage unit, coupled to the T/R pin set and powered by a first operation voltage, for storing device information of the electronic device;
• a charging unit coupled to the power pin;
• and
• a battery unit, coupled to the charging unit and charged by a charging voltage;
• wherein when the electronic device is in a power-exhaustion state and the power supply device is coupled to the second connection interface via the first connection interface to provide the first supply voltage to the power pin by the power switching unit, the voltage regulation unit transforms the first supply voltage to the first operation voltage, and the storage unit powered by the first operation voltage outputs the device information to the control unit via the signal T/R pin set,
• wherein when the control unit determines that the device information conforms to preset information, the control unit controls the power switching unit to provide the second supply voltage to the power pin, and the electronic device enters a charging state, and
• wherein in the charging state, the charging unit provides the charging voltage according to the second supply voltage.