Micron Technology Incorporated

Zhitong Chen

Tyler A Lowrey

Ward D Parkinson

Wen-Foo Chern

Gary M Johnson

Thomas M Trent

A voltage sensing circuit is used to rapidly pull up a high potential node of a reference array to a value of a high potential source reduced by a threshold voltage (V.sub.CC -V.sub.T). During an enable cycle, the high potential node is precharged to a potential of V.sub.CC -V.sub.T, which turns on a transistor gated to the V.sub.CC potential. This pulls the high potential node as rapidly as possible to a high level in order to speed up the sensing process. A potential maintenance circuit provides sufficient current from the high potential source to maintain a desired potential at the high potential node.

Pull up circuit for digit lines in a semiconductor memory

A memory array (e.g., DRAM) is provided with a potential maintenance circuit which provides sufficient current to maintain a high potential node of the memory array at a predetermined potential. The potential maintenance circuit is gated ON after receipt of a clock signal and gated OFF at the predetermined potential. This permits the high voltage node to be maintained, while reducing current requirements. The invention is particularly useful when used in conjunction with a circuit which rapidly pulls up the high node to a value of V.sub.CC -V.sub.T (where VT is a threshold voltage of a transistor).

Pull up circuit for sense lines in a semiconductor memory

A pumpdown circuit uses voltage sensing to bring a low node to a potential of V.sub.SS +V.sub.T by first grounding the node and then floating the node to the V.sub.SS +V.sub.T potential. When a sensing node is at the V.sub.SS +V.sub.T potential, the sensing node is maintained at a level above ground by leakage current through a pump-up circuit. Biasing the digit and digit* lines to a potential V.sub.T above ground reduces current (amperage) requirement, because the digit and digit* lines do not have to be discharged completely to ground. The momentary discharge of the sense amp node to ground allows the sense amp to behave like a conventional sense amp during initial sensing, thereby allowing a minimum digit/digit* sensing potential to approximate ground plus V.sub.T.

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Boise, ID, United States of America

Zhitong Chen