摘要 |
This invention relates to sensing single and multiple bit non-volatile memories to determine what value is represented, by sensing both the source and drain of the cell being read. Sensing of threshold voltages is employed as an alternative to current sensing. A reference cell or miniarray is used as an input to differential sensing amplifier. The other input sensed is the threshold voltage of the cell being read. By sensing both the source and drain of a selected memory cell, substantial gains in sensing small voltage differentials in memory cells operating at reduced voltages or storing multiple bits of data is achieved.
|