Semiconductor memory device capable of reducing power supply noise

Abstract

A semiconductor device reduces power supply noise during read operations of a memory device. The semiconductor device includes a plurality of read circuits, a plurality of control circuits and a plurality of output circuits. The read circuits are coupled to the memory device and responsive to a first enable signal to provide readout data during an active period thereof. The output circuits receive the readout data and output the readout data to an external device in response to a second enable signal. The control circuits are coupled between the read circuits and the output circuits and control the output circuits. The control circuits provide output data which is gradually changed to a preset logical value during the active period and to a value equal to the value of the readout data from the read circuits after termination of the active period.