An improvement of current driving and electrical conductivity properties in covetics

Compared to pure Cu, Cu lattice retaining carbon atoms, called a covetic material, can have better electrical conductivity. Furthermore, the incorporation of carbon nanostructures into Cu-alloys could improve the mechanical properties of Cu-alloys. In the simulation study, we investigated Joule heating due to applied DC current on molten Cu metal concerning how to improve current density of covetic materials. In addition, we will discuss interfacial effects on covetic-metal electrodes to meet better current driving performance. The covetic composite excited at one electrode (width = 10 nm) has a higher current drive capability as a value of 3.54 107 A/m2 , for 1000 A current at a temperature of 1073.2 K, this value is a constant while temperature is changing up to 1573.2 K. We measured the conductivity of the proposed covetic materials at various carbon nanotube densities at room temperature. Experimental results show the lowest resistivity value accomplished after mixing and temperature annealing as a value of 1.78 10−8 Ω.m, where the covetic sample has 1.27% carbon nanotube density, and that the electrical conductivity is superior to that of Cu-carbon nanotube composites previously report

Sensing Schemes for STT-MRAMs structured with high TMR in low RA MTJs

In this work, we investigated the sensing challenges of spin-transfer torque MRAMs structured with perpendicular magnetic tunnel junctions with a high tunneling magnetoresistance ratio in a low resistance-area product. To overcome the problems of reading this type of memory, we have proposed a voltage sensing amplifier topology and compared its performance to that of the current sensing amplifier in terms of power, speed, and bit error rate performance. We have verified that the proposed sensing scheme offers a substantial improvement in bit-error-rate performance. To enumerate the read operations of the proposed sensing scheme with the proposed cross-coupled capacitive feedback technique on the clamped circuity have successfully been performed a 2.5X reduction in average low power and a 13X increase in average reading speed compared with the previous works due to its device structure and the proposed circuit technique.This work is part of a project that has received funding from the European Union’s H2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 691178, and supported by the TUBITAK-Career project #113E76

Spin-Torque Memristor based Offset Cancellation Technique for Sense Amplifiers

Unpredictable threshold voltage changes of CMOS transistors cause input referred random offset (IRRO) in sense amplifiers. With the shrinkage of transistors in nano regime, it is being quite costly to cancel the offsets using conventional CMOS based techniques. Motivated by this fact, this study focuses on the IRRO cancellation with the aid of the spintorque memristor technology. Spin-torque memristors in series, compared to parallel, show less resistance and process variations. The resistance value of a spin-torque memristor is regarded as frozen when the current flow over the spin-torque memristor is lower than its critical switching current value. In fact, the proposed structure employs a non-destructive sensing scheme in order to achieve a relatively large sense margin by reducing the IRRO. Our main idea is to reduce or eliminate the IRRO by exploiting the spin-torque memristors for providing the current matching on the input transistors of the voltage comparator. In particular, the overwrite problem of the spin-torque memristor is solved by setting the critical switching current of the spin-torque memristor to be greater than a current value corresponding to the maximum IRRO value. We evaluate the IRRO cancellation technique on the proposed comparator or sense amplifier using 45nm predictive CMOS technology. Although sense amplifiers are targeted in this study, our technique can be applied to any analog amplifier suffering from the IRRO.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 691178

Gm/IDtransistör boyutlandirma tekniǧi kullanarak evirici tabanli OTA tasarimi

In this paper, transistor sizing of the inverter-based operational transconductance amplifier (OTA), which has been widely used in circuit applications recently, has been implemented with the gm-ID technique. Especially, considering the unit gain bandwidth, this design parameter is optmized with this technique. The proposed inverter-based OTA gain is 25dB, and the unity gain bandwidth value is 4.82 MHz, which is the simulation result, and 4.77 MHz, which is the calculated value. The simulated unit gain bandwidth frequency value, in particular, agrees with the measured value.Bu yayında, son zamanlarda devre uygulamalarında genisçe yer bulan evirici tabanlı operasyonel geciş iletkenliği kuvvetlendirici devresinin, gm-ID tekniğiyle transistor boyutlandırılması gerçeklenmiştir. Özellikle, birim kazanç bant genişliği tasarım parametresi bu teknikle optimize edilmiştir. Simulasyon sonuçlarına göre, amaçlanan evirici tabanlı OTA kazancı 25dB’dir ve birim kazanç bant genişliği ise 4.82 MHz simulasyon de geri olarak ve 4.77 MHz hesaplanan değer olarak elde edilmiştir. Bu sonuçlar, birim kazanç¸ bant genişliği parametre belirlenmesinde ki uygulanan methodun etkinliğini göstermektedir

An improvement of current driving and electrical conductivity properties incovetics

: Compared to pure Cu, Cu lattice retaining carbon atoms, called a covetic material, can have better electrical conductivity. Furthermore, the incorporation of carbon nanostructures into Cu-alloys could improve the mechanical properties of Cu-alloys. In the simulation study, we investigated Joule heating due to applied DC current on molten Cu metal concerning how to improve current density of covetic materials. In addition, we will discuss interfacial effects on covetic-metal electrodes to meet better current driving performance. The covetic composite excited at one electrode (width = 10 nm) has a higher current drive capability as a value of 3.54 107 A/m2 , for 1000 A current at a temperature of 1073.2 K, this value is a constant while temperature is changing up to 1573.2 K. We measured the conductivity of the proposed covetic materials at various carbon nanotube densities at room temperature. Experimental results show the lowest resistivity value accomplished after mixing and temperature annealing as a value of 1.78 10−8 Ω.m, where the covetic sample has 1.27% carbon nanotube density, and that the electrical conductivity is superior to that of Cu-carbon nanotube composites previously report

Emulation of a constant phase element by utilizing a lattice structure based fractional-order differentiator

In this paper, we propose a modular Constant Phase Element (CPE) emulator, the approximation order of which is electronically adjustable. In this way, the emulator provides a limited approximation error over a range of the parameter alpha, the order of the CPE. A fractional-order differentiator has been utilized in the emulator, which is realized by rational integer-order approximations implemented based on a lattice-type structure. The advantage of lattice-type implementation is the possibility of easily changing the order of approximation. It also provides the flexibility of compromising the approximation accuracy with power consumption. The emulator is accurate over five decades of frequency [0.1 Hz, 10 kHz] and provides electronic adjustability of the CPE capacitance, order, and operation frequency. The simulation results confirm the performance of the emulator. Two fractional band-pass filters (FBPF) are presented as an application of the CPE emulator, which are employed in electroencephalography (EEG) signal processing. One of the FBPFs is employed in extracting theta and alpha waves in the frequency range of 3-13 Hz; while the other filter is used for extracting the beta waves in the range of 13-30 Hz. The power consumption of the simulated FBPFs are 2.871 mu W and 1.836 mu W, respectively