Voltage dropping apparatus, voltage switching apparatus, and internal voltage supply apparatus using the same

A voltage switching apparatus comprising:

• a voltage output unit outputting a first voltage and a second voltage having a level lower than a level of the first voltage;
• a first switch unit connected to the voltage output unit, operating based on a first gate signal, and controlling an output of the first voltage based on a value of the first gate signal;
• and
• a second switch unit connected to the voltage output unit, operating based on a second gate signal, and controlling an output of the second voltage based on a value of the second gate signal,
• wherein the voltage output unit operates based on a third gate signal, and controls a difference between the level of the first voltage and the level of the second voltage based on a value of the third gate signal.

An internal voltage supply apparatus comprising:

• a source voltage supply unit supplying a source voltage in a first mode, and dropping a level of the source voltage and supplying the source voltage having the dropped level in a second mode;
• a reference voltage output unit outputting a first reference voltage in the first mode and outputting a second reference voltage having a level lower than a level of the first reference voltage in the second mode;
• an internal voltage output unit connected to the reference voltage output unit and outputting an internal voltage based on a level of a reference voltage output in the reference voltage output unit;
• and
• a control unit receiving a mode signal and controlling a change of modes of the source voltage supply unit and the reference voltage output unit based on a value of the mode signal.