Dijital Sistem Tabanlı Programlanabilir Memristör Emülatör Devre Tasarımı
Özet
The theory of memristor dates back to the 1970s, but its first physical application was announced by HP (Hewlett Packard) engineers in 2008. Memristor is widely defined as the fourth basic passive circuit element since it realizes the relationship between the flux and the charge. Memristor exhibits non-linear behavior when its current-voltage characteristic is examined. Another crucial feature is that the resistance value changes according to the applied voltage and maintains the last resistance value even if the applied voltage is removed. Thanks to these features of the memristor, which is a physically nano-sized device, it has a wide range of applications such as non-volatile memory structures, neuromorphic circuits, digital gates, chaos circuits and oscillator circuits. Besides HP's announcement of memristor, commercial off the shelf products are limited due to some manufacturing issues. In this thesis, a digital system based memristor emulator circuit is studied in order to observe HP memristor model in real-time applications. A structure consisting of a microcontroller and a digital potentiometer is used in the emulator circuit. A memristor emulator is first designed in MATLAB Simulink environment in order to observe memristor behavior and use it as a test criterion in hardware-based studies. Following the simulations, the emulator is designed and produced at the hardware level. In hardware-based tests, different signal inputs are applied to the memristor emulator and compared with the results obtained from the simulation environment. The designed emulator circuit is then used in a memristor-based square wave oscillator. Eventually, the studies show that the designed programmable memristor emulator functions successfully in real-time applications.
