A universal mem-element emulator with a single MO-OTA core: Memristor, memcapacitor, and meminductor in one reconfigurable circuit

Abstract

A universal mem-element emulator is built around a single multi-output operational-transconductance-amplifier (MO-OTA) core, one analog multiplier and one grounded resistor–capacitor pair. The same core reproduces the pinched-hysteresis dynamics of the memristor, the memcapacitor and the meminductor; only the front-end coupling and the reflection law change. An explicit state equation follows from Chua's flux–charge formulation, with the integrator voltage vC as the state. The memristor reflection law is calibrated against the Strukov–Williams compact model of an HP TiO2 device, matching its memristance excursion to 0.9% and its loop area to 5.9% over 5–100 kHz. Both active blocks are transistor-level in TSMC 0.18μm CMOS: a 15-MOSFET MO-OTA and a new 9-MOSFET four-quadrant multiplier that runs from ±0.9V with 0.16% THD and zero systematic offset. The 24-MOSFET emulator dissipates 0.61mW and preserves pinched v–i, q–v and φ–i loops from 1 kHz to 22MHz. Robustness spans 45 process–voltage–temperature corners and a 500-run Monte-Carlo analysis with per-device threshold-mismatch; the modulated element stays positive-definite in every run (σ/μ=9.7%). In the Itoh–Chua oscillator it yields a double-scroll attractor with λmax=0.311, against 0.276 for an ideal memristor. It stays fully floating, needs no mutator or switching network, and uses the smallest active-block count among universal emulators.