A 0.5-V 25-MHz 1-mW 256-kb MTCMOS/SOI SRAM for solar-power-operated portable personal digital equipment - sure write operation by using step-down negatively overdriven bitline scheme. - Nobutaro Shibata; Hiroshi Kiya; Shigehiro Kurita; Hidetaka Okamoto; Masa'aki Tan'no; Takakuni Douseki (IEEE J. Solid State Circuits, 2006)