A circuit includes a first transistor including first and second current terminals. The first current terminal couples to a supply voltage node. A second transistor includes a second control input and third and fourth current terminals. The third current terminal couples to the second current terminal at an output node and the fourth current terminal couples to a ground node. A third transistor includes a third control input and fifth and sixth current terminals. The fifth current terminal couples to the output node and the sixth current terminal couples to the ground node. A fourth transistor includes a fourth control input and seventh and eighth current terminals. The eighth current terminal couples to the ground node and the seventh current terminal couples to the third control input. An inverter having an input coupled to the second control input and an output coupled to the fourth control input.