A memory device includes a first memory cell, a second memory cell, a precharge circuit, a sense amplifier, a switch circuit, and a controller. The first memory cell is connected to a first bit line, the second memory cell is connected to a second bit line, and the precharge circuit connected between the first bit line and the second bit line. The sense amplifier includes a first input terminal and a second input terminal. The switch circuit is connected to the first bit line and the first input terminal and to the second bit line and the second input terminal and is configured to control a connection between the first bit line and the first input terminal and a connection between the second bit line and the second input terminal in response to a switch signal. The controller is configured to generate the switch signal in response to a command.