Normally-off Logic Based on Resistive Switches—Part I: Logic Gates

To extend the scaling of digital integrated circuits, beyond-CMOS approaches based on advanced materials and novel switching concepts are strongly needed. Among these approaches, the resistive switching random access memory (RRAM) allows for fast and nonvolatile switching at scalable power consumption. This work presents functionally complete logic gates based on RRAM technology. Logic computation is obtained through conditional switching in RRAM circuits with serially connected switches. AND, implication, NOT, and bit transfer operations are demonstrated, each using a single clock pulse, while other functions (e.g., OR and XOR) are achieved in multiple steps. The results support RRAM logic for normally-off digital circuits with extremely high density.