Patent ID: 7821228

Claim:
A mobile phone charger for charging a mobile phone, comprising: a battery module configured for receiving at least one battery therein, and providing an operating voltage from the at least one battery; a boosting and charging circuit comprising a DC-DC converter chip, an input terminal of the DC-DC converter chip receiving the operating voltage from the battery, when the operating voltage of the battery is substantially higher than a reference voltage of the DC-DC converter chip, the DC-DC converter chip being activated and raising the operating voltage, and an output terminal of the DC-DC converter chip outputting the raised operating voltage as a charging voltage; a low voltage boosting circuit comprising a DC step-up chip, a voltage input terminal of the DC step-up chip connected to a positive terminal of the at least one battery to receive the operating voltage therefrom when the operating voltage is substantially lower than the reference voltage and insufficient to activate the DC-DC converter chip, the DC step-up chip raising the low operating voltage to be substantially higher than the reference voltage and outputting the raised operating voltage to the input terminal of the DC-DC converter chip; and a mobile phone charging interface connected to the output terminal of the DC-DC converter chip to receive the charging voltage, and providing the charging voltage to the mobile phone.