Zainulabideen Jamal Khalifa

Memristor emulator based on single CCII

With the introduction of the memristor design by the HP lab, there has been a surge of interest to perform different theoretical and experimental works to investigate various potential applications of the memristor. However, since the memristor is not available commercially, it is essential to design the emulator circuit for the memristors from the available electronic components. In this paper, we present the validation of a previously published memristor emulator through experimentation and introduce a simpler memristor emulator circuit that is built using only one second generation current conveyer (CCII), two diode-connected transistors, a capacitor and some resistors. The proposed circuit satisfies the fingerprints of the memristor in the I-V plane accurately. The circuit is very simple to implement in the lab for educational purpose. Furthermore, the mathematical model and analysis of the proposed emulator circuit are introduced. SPICE simulation and experimental results are also provided.

A new simple emulator circuit for current controlled memristor

This paper introduces a new and simple emulator circuit for a current controlled Memristor. The proposed emulator circuit consists of only two second-generation current conveyors (CCII+) to achieve the hysteresis behavior of the Memristor in the I-V plane. The emulator circuit satisfies the well-known fingerprints of Memristors. This circuit is very simple and realistic comparable to the previously published circuits. Here, mathematical analyses and PSPICE simulations are provided to validate the presented circuit. Experimental results show very good match with the simulation results.

Independent control of the frequency and condition of oscillation: a caution

Over the years researchers have developed and reported a huge number of sinusoidal oscillator circuits and classified them, according to the tunability of their frequencies of oscillation, as enjoying independent control of the frequency and condition of oscillation. This classification is based on obtaining the frequency and the condition of oscillation using the Barkhausen criterion. This article serves as a caution as it appears that this classification is incorrect. Experimental and SPICE simulation results that support this caution are included.

Electrical Nonlinearity Emulation Technique for Current-Controlled Memristive Devices

Emerging memristor technology is recently drawing widespread attention due to its potential for diverse applications. Due to the lack of real solid-state memristive devices, there have been many initiatives to develop memristor emulators to study their behavior and applications. One of the most widely used ideal memristor models developed by the HP Lab does not fit the anticipated nonlinear behaviors of a real memristor. In this paper, we propose the concept and the design of a practical memristor emulator, which can be used to mimic the behavior of the well-known current controlled memristor models like-Simmons tunneling barrier model and the ThrEshold adaptive memristor model. Our proposed emulator model mimics the behavior of the electrical nonlinearity of the fabricated memristor. Prior emulators can only emulate the linear electrical behavior. In addition to the mathematical modeling and analysis of the proposed emulator, we provide SPICE simulation and experimental results. Furthermore, the proposed emulator has been used to verify some applications like Wien Oscillators. Finally, a brief comparison with the previously published emulators is presented to highlight the advantages of the proposed design.

Simple generic memristor emulator for voltage-controlled models

In recent times, memristors have drawn wide spread attention from the research community due to their potential applications in memory and various other systems. However, as of now, no solid state device could be designed to achieve the memristive behavior. The research community has been trying to build emulator circuits to study the behavior of the memristor due to the lack of the solid state memristor samples. In this paper, we introduce a generic and simple emulator circuit for a voltage controlled memristor. Although, the voltage-controlled memristor models are of great importance, no significant research has been done to build emulator circuits for this type of memristor. We propose an emulator circuit design comprised of only two second generation current conveyers (CCII+) and one multiplier to achieve the hysteretic behavior of the memristor. We also present the mathematical modeling and SPICE simulation of the proposed emulator circuit. Experimental results show proper matching with the results obtained from the SPICE simulation.

A New Capacitor-Less Buck DC-DC Converter for LED Applications

In this paper, a new capacitor-less DC-DC converter is proposed to be used as a light emitting diode (LED) driver. The design is based on the utilization of the internal capacitance of the LED to replace the smoothing capacitor. LED lighting systems usually have many LEDs for better illumination that can reach multiple tens of LEDs. Such configuration can be utilized to enlarge the total internal capacitance and hence minimize the output ripple. Also, the switching frequency is selected such that a minimum ripple appears at the output. The functionality of the proposed design is confirmed experimentally and the efficiency of the driver is 85% at full load.

A novel operational amplifier-based square/triangular/sinusoidal oscillator

This paper shows that the classical square/triangular wave generator can also provide sinusoidal oscillations. Thus, a square/triangular/sinusoidal oscillator can be obtained from the same topology by changing a resistance. A new sinusoidal oscillator using two operational amplifiers, one resistor, and one capacitor is also shown. Experimental results that confirm the operation of the proposed circuits in different regimes are included.

A new capacitor-less LED drive

In this paper a new capacitor-less LED drive is proposed. The design is based on the utilization of the internal capacitance of the LED to replace the smoothing capacitor. LED lighting systems usually have many LEDs for better illumination that can reach multiple tens of LEDs. Such configuration can be utilized to enlarge the total internal capacitance and hence minimize the output ripple. In addition, the switching frequency is selected such that minimum ripple appears at the output. The functionality of the proposed design is confirmed experimentally and the efficiency of the drive is 85% at full load.