Abstract: In described examples, an integrated circuit includes first and second transistors, a switch, a capacitor, a resistor, and first and second comparators. A first terminal of the switch is coupled to a first terminal of the resistor. A second terminal of the switch is coupled to a second terminal of the resistor, a first terminal of the capacitor, and a gate of the first transistor. The first comparator is configured to receive at the first input a first reference voltage, and an output of the first comparator is coupled to a gate of the second transistor. The second comparator is configured to receive at the first input a second reference voltage. A second input of the second comparator is coupled to a second input of the first comparator. An output of the second comparator is coupled to a control input of the switch.