Abstract: An arcing fault protection assembly and a corresponding method determine whether arcing is present in electrical circuits. The assembly powers-up quickly without dissipating excessive heat while power is being supplied to the assembly. The assembly comprises a sensor, a broadband noise circuit, a controller, and a dual-mode power supply. The sensor detects a current flowing in an electrical circuit and develops a corresponding sensor signal. The broadband noise circuit determines the presence of broadband noise in the sensor signal and produces a corresponding output signal. The controller processes the sensor signal and the output signal in a predetermined fashion to determine whether an arcing fault is present in the circuit. The dual-mode power supply supplies power to the sensor, broadband noise circuit and controller using a first mode and later switching to a second mode. The first mode reaches steady state faster than the second mode.