Voltage generator for a nonvolatile memory device, and a method of operating the voltage generator

A voltage generator of a nonvolatile memory device includes a charging circuit, a current mirror circuit, a discharging circuit and an output circuit. The charging circuit amplifies a difference between a reference voltage and a feedback voltage to generate a first current. The current mirror circuit is connected to the charging circuit and generates a second current based on the first current. The discharging circuit is connected to the current mirror circuit to draw the second current, and discharges the output voltage to a target level by adjusting discharging amount of the second current based on a sensing voltage which reflects a change of the feedback voltage. The output circuit is connected to the current mirror circuit, and provides the output voltage based on the first current and the second current to a first word-line connected to an output node.