Semiconductor memory device and sense amplifier

摘要

A semiconductor memory device having a memory plane defined by a plurality of memory cells, a decoder line for accessing the memory cells, a common data line on which a signal output from an accessed memory cell is collected, and a sense amplifier for amplifying the signal collected on the common data line. The sense amplifier has an amplifying circuit portion which is composed of a pair of common-collector type bipolar transistors supplied with the signal collected on the common data line as a differential input, and a plurality of MOS transistors for converting a change in current into a change in voltage. Each of the MOS transistors has a lightly-doped drain structure.