Fig. 2: 6-transistors 2-memristors analog content-addressable memory circuit.

a Schematic of our proposed analog CAM circuit, composed of six transistors and two memristors (6T2M). Voltage amplitude on the Data Line (DL) provides search input and the matching result is sensed as the voltage level on the Match Line (ML). b “Match” result when the analog input is within the range (narrow green band) stored by the cell. The stored range is defined by the conductances of two memristors (M1 and M2) in the cell, with M1 determining the lower bound and M2 determining the upper bound of the matching range. c,d Voltage divider sub-circuits translate the input voltage (a search value) to the gate voltage on the ML pull-down transistors. c When the input voltage is smaller than the lower bound threshold, the voltage on the gate of the T1 is large enough to pull down the ML, yielding a “mismatch” result. The lower bound threshold is set by the M1 memristor conductance. d Similarly, when the input voltage is larger than the upper bound threshold, which is tuned by the M2 memristor conductance, the cell returns a “mismatch” result by pulling down the ML. Here, SL_hi is at 0.5 V which sets the max G1 and G2 voltage.