Noise reduction device and semiconductor device having the same

A noise reduction device to be disposed in a semiconductor device that is connected to an internal circuit, comprising:

• a first noise reduction circuit;
• and
• a second noise reduction circuit,
• wherein said first noise reduction circuit includes
• a first Schmitt circuit for receiving a first signal from a first terminal disposed in the semiconductor device and outputting a first output signal;
• and
• an output signal adjusting unit for adjusting and outputting a second output signal to the internal circuit when the first output signal is maintained for a specific period of time after the first output signal is varied, and
• said second noise reduction circuit includes
• a second Schmitt circuit for receiving a second signal from a second terminal disposed in the semiconductor device;
• and
• an input signal adjusting unit for adjusting the second signal input to the second Schmitt circuit according to a fluctuation of a power source voltage applied to the semiconductor device so that the second Schmitt circuit outputs a third output signal to the internal circuit.