A circuit for power supply and supplying method thereof

PURPOSE: A power supply terminal and a method for supplying power using the same are provided to support each terminal function optimally as being applicable to various terminals. CONSTITUTION: A power supply interface is supplied with power. A converter(20) and a charging circuit(50) are connected to the power supply interface in parallel. A battery(60) is supplied with the power of the charging circuit, and provides the stored power to a system(40). The system is selectively supplied with the power of the converter and the charging circuit. A main switch is arranged between the battery and the system. The main switch blocks power supply of the battery transferred to the system. A control logic part(70) turns on or off the main switch according to the power supply from the power supply interface.