A circuit includes an input circuit, a level shifter circuit, an output circuit and a feedback circuit. The input circuit is coupled to a first voltage supply, and configured to receive a first input signal, and to generate a second input signal. The level shifter circuit is coupled to the input circuit, and configured to receive an enable signal, the first input signal or the second input signal, and to generate a first signal responsive to the enable signal or the first input signal. The output circuit is coupled to the level shifter circuit, and is configured to receive the first signal, and to generate an output signal or a set of feedback signals responsive to the first signal. The feedback circuit is coupled to the level shifter circuit and output circuit, and is configured to receive the enable signal or the set of feedback signals.