According to one embodiment of the present disclosure, a circuit includes a Correlated Electron Switch (CES) element and a programming circuit. The CES element includes a first input. The first input of the CES element is coupled to an input signal to be monitored. The CES element is programmed in a first impedance state. The programming circuit coupled to the CES element is configured to switch the CES element from the first impedance state to a second impedance state in response to a voltage transition on the input signal. The voltage transition indicates a fault event. The output element coupled to the first input of the CES element determines that the transition has occurred responsive to the CES element switching to the second impedance state.