SUBSTRATE POTENTIAL GENERATING CIRCUIT AND SEMICONDUCTOR MEMORY DEVICE PROVIDED WITH SAME

摘要

PROBLEM TO BE SOLVED: To solve such a problem that in a semiconductor memory device provided with a substrate potential generating circuit, when operation is shifted from high speed operation to refresh operation, a time period of high temperature and large substrate potential exists, in this time period, a junction leak current becomes large due to high temperature and high junction bias voltage, thereby, defective refresh is caused in a memory cell having a short data holding time.;SOLUTION: The substrate potential generating circuit outputs a substrate potential by an oscillation control signal in which a reference potential having temperature dependency is compared with a substrate potential. The reference potentia is made high in high temperature and the substrate potential is made low by making the reference potential be the reference potential having temperature dependency. Occurrence of defective refresh of a DRAM can be prevented by making the substrate potential low and suppressing junction leak of the memory cell in high temperature.;COPYRIGHT: (C)2008,JPO&INPIT