Method and apparatus for detecting current using operational amplifier

A current detecting method of a conductor comprising:

• applying a current to a shunt resistor connected to the conductor;
• applying a voltage of a first end of the shunt resistor to a first input terminal of an operational amplifier by being voltage-divided through a first resistor and a third resistor, and applying a voltage of a second end of the shunt resistor to a second input terminal of the operational amplifier by being voltage-divided through a second resistor and a fourth resistor;
• and
• determining the current of the conductor based on the voltage of an output terminal of the operational amplifier,
• wherein the first resistor is connected between the shunt resistor and the first input terminal of the operational amplifier, the second resistor is connected between the shunt resistor and the second input terminal of the operational amplifier, the third resistor is connected between a ground and the first input terminal of the operational amplifier, and the fourth resistor is connected between the ground and the second input terminal of the operational amplifier.