Patent ID: 8649827

Claim:
A power supply unit for mobile terminals, comprising: a power supply conversion module; a charging management module; and a power supply switching module, wherein said charging management module and power supply switching module each comprise a power supply input port used for connection with an external power supply; wherein said charging management module is connected with a battery and used for charging the battery when the external power supply is connected, wherein said power supply conversion module is connected with said power supply switching module and used for converting a voltage of an external power supply into power supply voltage required by a mobile terminal and controlling an on-off state of said power supply switching module, wherein the power supply switching module is in an on state when no external power supply is connected and the battery supplies power to the mobile terminal, and wherein said power supply switching module is off and said power supply conversion module outputs the power supply voltage when the external power supply is connected, wherein said power supply switching module comprises a second resistor, a third resistor and a field effect transistor, wherein said second resistor and third resistor are connected in series to form a voltage sampling circuit, one end of said third resistor is connected with said power supply conversion module, a voltage dividing point of said voltage sampling circuit is connected with a gate of said field effect transistor, and a source of said field effect transistor is connected with said battery.