A boosted voltage generator may include a difference voltage generator, a first charging circuit, a second charging circuit and a switch circuit. The difference voltage generator generates a difference voltage to a first node, based on a reference voltage and a power supply voltage. The first charging circuit, connected between the first node and a ground voltage, charges the difference voltage therein during a first phase in response to a first pulse signal. The second charging circuit, connected between the first node and the ground voltage, charges the difference voltage therein during a second phase in response to a second pulse signal. The switch circuit, connected to a second node in the first charging circuit, a third node in the second charging circuit and an output node, provides a boosted voltage following a target level to the output node during each of the first phase and the second phase.