Abstract: According to one exemplary embodiment, a circuit configured to interface with an etch tool comprises an ESC input for receiving a first signal from the etch tool, where the first signal indicates a magnitude of a chuck current passing through a chuck holding a wafer in the etch tool. The circuit further comprises a VRF input for receiving a second signal from the etch tool, which indicates a magnitude of a voltage difference between a plasma and the chuck in the etch tool. The circuit further comprises an arc detect output indicating whether an arc event has occurred. The circuit can be configured to prevent the arc detect output from indicating an occurrence of a chucking spike and a de-chucking spike in the etch tool.