SEMICONDUCTOR STORAGE DEVICE

PURPOSE:To reduce the current consumption in operation by providing a node connectable to a power voltage terminal to each sense amplifier, precharging the node in advance and using the level as a reference level of the sense amplifier. CONSTITUTION:A control signal phiPC changes to an L level just before a word line WL rises to an H level and a precharge MOSFET QP and switch MOSFETs QS1 - QS3 are turned off. Then nodes nr1,nr2,nr3 at reference side of each sense amplifier are floated. Then the level of the line WL changes to an H level, an information charge of a memory cell MC on the word line is read onto a bit line BL respectively thereby changing the level of the bit line. Then a sense amplifier SA is active to detect a level difference between the bit line and the reference node nr and amplify the difference. Then column switches Qy,Qy' are closed and only one amplifier SA connects to a common input and output signal line i/o, an amplifier AM is driven, a read signal is amplified and the result is outputted externally through an output buffer DOB.