Voltage controller and memory device including same

A memory device includes a memory cell array including a plurality of memory cells storing data, a sense amplifier connected to the memory cell array, and a voltage controller. The voltage controller includes a voltage driver that generates a control signal and an overdrive controller that generates an overdrive control signal that regulates the generating of the control signal in response to at least one of a result of a comparison between the control signal and a reference voltage, and process, voltage, temperature (PVT) information. The voltage driver adjusts the control signal in response to the overdrive control signal to generate an overdriven control signal and outputs the overdriven control signal to the sense amplifier.