The disclosure provides a detector that includes a pre-charge circuit. The pre-charge circuit receives a supply voltage. A pre-charged comparator is coupled to the pre-charge circuit and receives the supply voltage. The pre-charged comparator generates a transition signal at a transition node. A slope of the transition signal is greater than a slope of the supply voltage. A first diode connected transistor receives the supply voltage. A first capacitor is coupled to the first diode connected transistor. An inverter is coupled to the first diode connected transistor and generates an enable signal when the supply voltage is below a threshold voltage.