| 摘要 |
A memory device has been described that can read data stored in non-volatile memory cells using a differential voltage sensing technique. The memory includes a differential voltage sensing circuit having two input nodes. The nodes of the sensing circuit are pre-charged to different initial voltage levels prior to reading the memory cell. The nodes are pre-charged by charge sharing multiple bit lines during two charge sharing cycles. During a first cycle, both nodes are pre-charged to a common voltage level. During the second cycle, a reference node is further charge shared to reduce its voltage. A selected node that is coupled to a memory cell to be read is pre-charged to a higher value than the second sensing node. After a word line coupled to the memory cell is activated, the initial differential voltage between the sensing nodes will remain if the memory cell is programmed such that it does not conduct current in response to the word line signal. If the memory cell is not programmed, the memory cell will discharge the selected sensing node to provide a different differential voltage to be sensed.
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