An Offset Readout Current Sensing Scheme for One-Resistor RRAM-Based Cross-Point Array

The uneven sneak-path currents in resistive random access memory (RRAM) severely constrain the array size. To overcome this issue, we propose an innovative readout scheme that can fully offset the sneak-path currents in one-resistor (1R) RRAM array. Furthermore, the bit cell resistance (R
_cell
) in an RRAM array can be simply evaluated as the ratio of read voltage (V
_read
) to the sensed offset current (I
_offset
). Even under extreme device distribution, a 512×512 array size is still obtained. This is the largest array among simple 1R RRAM, without using a selector device or extra transistor.