Universal memelement emulator using only off-the-shelf components

The memelement emulation using Operational Transconductance Amplifiers (OTAs) has been quite popular in the last decade. Interestingly, a detailed literature survey reveals that only voltage-biased OTAs have been used so far, for their emulators, which may be due to the ease of linear memelement function realization (through just bias voltage application by employing a capacitance). But this technique has disadvantages; most commercially available OTAs are current biased, voltage biasing does not provide a better range for tunability, and current biasing is more stable and can be easily provided through current mirrors in large circuits. Therefore, the presented work proposes a Universal memelement emulator (UME) using only current-biased Active elements (which are purely off-the-shelf). The developed UME uses four single output OTAs, one CCII (Second Generation Current Conveyor) along with only three grounded passive elements. Overall, the designed circuit configuration is based on just forty CMOS transistors, which is the least as compared to other existing UMEs. And also, the exhibited operating frequency limit is found to be in the MHz range for memristor and above 100 kHz for other realized memelements. The paper also describes the application examples of proposed UME in the relaxation oscillator and in a neuromorphic circuit exhibiting the Amoeba behavior. To verify the designed circuits, the simulations have been executed in PSPICE using 0.18 µm CMOS technology. Lastly, the realization of the proposed UME has been shown via commercial ICs; LM13700 and AD844, and results are presented.