Differential subthreshold read of memory cell pair in a memory device

Abstract

Systems, methods, and apparatus related to memory devices. In one approach, a differential read operation is performed on a memory cell pair. Bitlines or digit lines are used to select the memory cells. The read operation is performed in a subthreshold mode in which the memory cells of the pair do not threshold (e.g., do not switch or snap). A voltage on a wordline used to select the memory cell pair is ramped to increasing magnitudes of voltage while the bitline or digit line voltages are held fixed. One or more detectors are used to determine a difference in leakage currents of the two memory cells. A logic state is determined (e.g., using at least one detector) based on the difference in leakage currents. A feedback circuit reduces voltages applied to the bitlines or digit lines in order to avoid thresholding the cells. The voltage reduction by the feedback circuit is triggered when the reading of the memory cell pair is complete.

Dependencies are inferred from the claim text.