An electronic device that is configured to be coupled to an alternating current (AC) power unit that includes an AC input power signal is described. The electronic device includes a reference signal generator circuit that is configured to generate a reference signal based on a direct current (DC) power source, a voltage divider circuit that is configured to scale the reference signal for application to the AC input power signal to generate a divided AC input power signal, an amplifier circuit that is configured to output a fault indication signal responsive to the divided AC input power signal, and an amplifier control circuit that is coupled to the amplifier circuit and is configured to control a fault indication signal level of the fault indication signal that is output by the amplifier circuit. Related methods and computer program products are also described.