SUBSTRATE POTENTIAL GENERATING CIRCUIT OF SEMICONDUCTOR STORAGE DEVICE

摘要

PURPOSE:To obtain the substrate potential generating circuit of a semiconductor storage device which has a small variation in substrate potential and is low in power consumption. CONSTITUTION:A reference potential Vref and a substrate potential VBB are decided through a comparator circuit 2. When the difference between Vref and VBB is large, a main bias circuit 5 and an external clock synchronizing type bias circuit 7 are operated and make VBB close to Vref. Furthermore, when the difference between Vref and VBB is small, only a subbias circuit 6 is operated and VBB is held close to Vref without wasting excess power.