a first power supply line and a second power supply line;

a switch module, configured to control an electrical connection of the first power supply line and the second power supply line between an input end and an output end;

a leakage current detection module, including a first leakage current detection line and a second leakage current detection line, wherein the first leakage current detection line covers the first power supply line and is configured to detect a leakage current from the first power supply line and to generate a first leakage signal in response thereto, and wherein the second leakage current detection line covers the second power supply line and is configured to detect a leakage current from the second power supply line and to generate a second leakage signal in response thereto;

a signal processing module, coupled to the leakage current detection module to receive the first and/or second leakage signals, and configured to generate a leakage fault signal in response to the first and/or second leakage signals, wherein the signal processing module includes a comparing unit configured to have a threshold signal, the comparing unit being selected from a group consisting of: a Zener diode, a trigger diode, and a TVS (Transient Voltage Suppressor) diode, wherein the threshold signal is defined by the Zener diode or the trigger diode or the TVS diode;

a trigger module, coupled to the switch module and the signal processing module, configured to receive the leakage fault signal, and in response thereto, to drive the switch module to disconnect the electrical connection between the input end and the output end; and

wherein in response to an output signal from the leakage current detection module that is below the threshold signal, the signal processing module prevents the trigger module from driving the switch module to disconnect the electrical connection between the input end and the output end, and in response to at least one of the first leakage signal and the second leakage signal received from the leakage current detection module which is above the threshold signal, the comparing unit generates the leakage fault signal.