A memory device includes a first signal line; a memory cell array divided into a first area and a second area and having a plurality of first memory cells and second memory cells in the first area and second area, respectively. The plurality of first and second memory cells are coupled the first signal line, and each has a reference node. A first voltage adjustment circuit adjusts voltages at the reference nodes of the plurality of first memory cells, wherein the first voltage adjustments circuit includes: a first switch coupled between the reference nodes of the plurality of first memory cells and the ground, controlled by an address signal; and a first bias element coupled to the reference nodes of the plurality of first memory cells. A second voltage adjustment circuit adjusts voltages at the reference nodes of the plurality of second memory cells.