Virtual-ground sensing techniques for a 49-ns/200-MHz access time 1.8-V 256-Mb 2-bit-per-cell flash memory. - Binh Quang Le; Michael Achter; Chin Ghee Chng; Xin Guo; Lee Cleveland; Pau-Ling Chen; Michael Van Buskirk; Robert W. Dutton (IEEE J. Solid State Circuits, 2004)