Current sensing circuit

A current sensing circuit for an electronic system, wherein the electronic system comprises a to-be-sensed circuit, a first voltage terminal of the to-be-sensed circuit is coupled to a first winding, a second voltage terminal of the to-be-sensed circuit is coupled to a second winding, and the current sensing circuit comprises:

• a sensing resistor disposed in the to-be-sensed circuit and coupled between the first voltage terminal and the second voltage terminal;
• a current monitor comprising a first terminal and a second terminal, wherein the first winding is coupled between the first terminal and the first voltage terminal, and the second winding is coupled between the second terminal and the second voltage terminal;
• a first variable resistor connected in series with the first winding between the first terminal and the first voltage terminal;
• and
• a processor coupled to the current monitor;
• wherein the current monitor obtains a sensed current according to a first voltage on the first terminal, a second voltage on the second terminal, and an impedance of the sensing resistor and generates a sensing signal according to the sensed current, and
• wherein the processor receives the sensing signal and determines whether to adjust an impedance of the first variable resistor according to the sensing signal.