Semiconductor device having plural internal voltage generating circuits and method of controlling the same

A device comprising:

• first and second power supply lines;
• a plurality of internal voltage generating circuits each supplying a first voltage to the first power supply line;
• a comparison circuit comparing the first voltage with a reference voltage to generate a comparison signal, the comparison signal indicating a first logic level when the first voltage is lower than the reference voltage and indicating a second logic level when the first voltage is higher than the reference voltage;
• a first load circuit operating on the first voltage;
• a second load circuit operating on a second voltage supplied from the second power supply line;
• and
• a control circuit generating a control signal, the control signal indicating a third logic level when the second load circuit is in an active state and indicating a fourth logic level when the second load circuit is in an inactive state, wherein
• the internal voltage generating circuits include at least first and second internal voltage generating circuits,
• the first internal voltage generating circuit is activated when the comparison signal indicates the first logic level and the control signal indicates the fourth logic level, and deactivated when the comparison signal indicates the first logic level and the control signal indicates the third logic level or when the comparison signal indicates the second logic level, and
• the second internal voltage generating circuit is activated regardless of a logic level of the control signal when the comparison signal indicates the first logic level, and deactivated when the comparison signal indicates the second logic level.