A threshold voltage detection apparatus comprises a voltage level up-shifter and a voltage level down-shifter. The threshold voltage detection apparatus is placed at a circuit fabricated in a low voltage semiconductor process. The threshold voltage detection apparatus receives an input signal having a wide range and generates output signals comprising the logic of the input signal, but having a voltage range suitable for the low voltage circuit. The threshold voltage detection apparatus ensures that the low voltage circuit operates in a range to which the low voltage semiconductor process is specified.