Nonvolatile memory device and memory system including thereof

Abstract

A nonvolatile memory device includes a memory cell array including a plurality of memory cells that are programmed based on a high voltage, a high voltage generator to generate the high voltage by boosting an input voltage based on a pumping clock, a pumping clock generator to generate the pumping clock, a high voltage detector to generate a detection signal by comparing an adjustment voltage with a reference voltage, a programming current controller to adjust a programming current flowing through each of selected memory cells of the plurality of memory cells; and a control logic to adjust a frequency of the pumping clock and a current driving capability of the programming current based on the detection signal during a programming period with respect to the selected memory cells. The detection signal includes information indicating whether the high voltage reaches to a target voltage.