Leakage current detection systems and detection methods are provided. A leakage current detection system includes a passive bridge circuit including a first branch having a first output and a second branch having a second output, a first output pad electrically connected to the first output, a second output pad electrically connected to the second output, a leakage surge structure disposed between the first output pad and the second output pad, where the leakage surge structure is connected to a low-ohmic node and is configured to draw a leakage current from the passive bridge circuit and pull voltages at the first and the second output pads in a same direction on a condition that the leakage current flows through at least one element of the passive bridge circuit, and a processing device configured to monitor for the leakage current and output a monitored result.