Semiconductor device having hierarchical sense amplifiers assigned to multiple local bit lines

摘要

A semiconductor device is equipped with memory cells which are provided at the intersections of word lines and local bit lines, hierarchical switches which are respectively connected between the local bit lines and a global bit line, and a hierarchical sense amplifier which amplifies a potential difference generated between signal nodes, with the signal nodes being respectively connected to the local bit lines. According to the present invention, because the hierarchical sense amplifier is a differential type circuit, a stable sensing operation can be performed. In addition, because one hierarchical sense amplifier can be assigned to multiple local bit lines, the number of hierarchical sense amplifiers can be reduced.