US Patent 9147483 Apparatus and method of operating memory device

A memory device useable with a memory system includes a voltage generator to a plurality of first candidate voltages and a plurality of second candidate voltages, and an X decoder to sequentially apply each of the plurality of first candidate voltages and each of the plurality of second candidate voltages to one or more cells of a memory cell array, and then to apply one of the plurality of first candidate voltages and one of the plurality of second candidate voltages as a first read voltage and a second voltage, respectively, to read data from the cells of the memory cell array according to a characteristic of the cells of the memory cell array.