A voltage generator including an LDO (low dropout) regulator that supplies a current to an internal voltage node of a sense amplification circuit as feedback control based on a voltage level of the internal voltage node; and a power switch circuit including a plurality of power switches each having one end connected to an external voltage and an opposite end connected to the internal voltage node, and that supplies the current to the internal voltage node as feed-forward control based on a known number of sense amplifiers to be activated. The voltage generator may efficiently supply current according to an operation mode of the sense amplification circuit.