A circuit configurable for indicating a voltage level of an input signal applied to the circuit includes at least one transistor having a first terminal connected to a first voltage supply, a second terminal configured for receiving the input signal, and a third terminal operatively coupled to an output of the circuit. The circuit further includes a passive load connected between the third terminal of the transistor and a second voltage supply. The circuit is configured to generate an output signal at the output of the circuit. The output signal being at a first value indicates that the input signal is substantially at a first voltage level, and the output signal being at a second value indicates that the input signal is substantially at a second voltage level.