Substrate potential control circuit capable of making a substrate potential change in response to a power-supply voltage

摘要

In a substrate potential control circuit, first and second substrate potential detection circuits have different intersected characteristics of Vcc versus VSUB detection level and produce, in response to a substrate potential VSUB, first and second substrate potential detection signals SUBUP1 and SUBUP2, respectively. A composition circuit composes the first and the second substrate potential detection signals SUBUP1 and SUBUP2 to produce a composite substrate potential detection signal SUBUP. Responsive to the composite substrate potential detection signal SUBUP, a back bias generation circuit generates a back bias signal BBG. Responsive to the back bias signal BBG, a pumping circuit makes the substrate potential VSUB by pumping.