Subthreshold-current reduction circuits for multi-gigabit DRAM's

Subthreshold-current reduction, especially at room-temperature operation, is one of the key design issues in the gigabit era. Despite its importance, however, a scheme for it has not been proposed. In this paper, innovative circuits featuring a hierarchical power-line scheme and a switched-power-supply CMOS inverter with a level holder are proposed. They can drastically reduce even the active current of a 16 Gbit DRAM by one tenth, from 1.2A to 116mA.