US Patent 7460423 Hierarchical 2T-DRAM with self-timed sensing

An embodiment of the present invention is an array of 2 transistor DRAM cells organized in rows and columns in which the rows represent words and columns represent bits of the words, each bit column having a pair of balanced, true and complement bit lines, the bit lines being connected in a hierarchical bit line structure, comprising at least one local bit line pair and one global bit line pair, a sensing circuit connected to the global bit line pair detects a differential voltage transition on either line during a read access and provides a sensing strobe signal.