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Recently, we reported on the appearance of a double peak in the switching current during the reverse poling. In the present paper, the switching current measurements have been carried out on a soft lead zirconate titanate as a function of grain size. While in small grains only a small single switching peak is observed, large grains, however, showed double peak switching, as commonly observed in this material. The pyroelectric coefficient curves show a consistent trend with the switching curves. This behavior is attributed to non-180° domain switching during the reversed poling case as a result of residual stresses developed during forward poling. [ABSTRACT FROM AUTHOR]

A modular isolated soft-switching dc–dc converter that can offer two levels of fault tolerance is proposed. A typical application is the wind energy conversion system used in offshore series-dc wind farm concept. The converter consists of input-parallel-output-series (IPOS) connected modules. Each module is a full-bridge dc–dc converter with an active rectifier, which can achieve zero voltage switching for all primary side switches and zero current switching for all secondary side switches and diodes. Under normal operation, the converter is operated with secondary phase-shifted modulation. When tolerable fault occurs in certain module, reconfiguration method ensures uninterrupted operation for the system. Additionally, modular structure provides another level of fault tolerance. More benefits of IPOS structure include reduced input current and output voltage of each module, module shedding capability, reduced ripple content due to interleaving, intrinsic balancing, and scalable control method. Both normal and faulty operations are simulated and also verified by scaled-down prototype experiment. [ABSTRACT FROM AUTHOR]

A trend for low-power conversion system is to integrate every component to a single chip. Magnetic component has been the key to determine the power density of the integrated switching power converter. In this paper, a hybrid resonant buck-type converter with an ultracompact custom-designed coupled inductor is presented for low-power integrated on-chip applications. This converter achieves zero-voltage switching for the high-side switch and near zero-voltage zero-current switching for low-side and auxiliary switches. The soft-switching condition allows the circuit operating at high switching frequencies. An ultracompact planar coupled inductor with a dimension of 5.25 mm × 1.95 mm × 3.86 mm is designed and customized for future integrated on-chip applications. The high-power density of this magnetics component is achieved by high switching frequency and optimized printed circuit board (PCB) windings design. A hardware prototype with 24 to 60-V input and 3.3 to 5-V, 3-A output operating at 2–3 MHz is presented to verify the circuit operation. The prototype achieves a peak efficiency of 90.7% using silicon devices at 2-MHz switching frequency. [ABSTRACT FROM PUBLISHER]

A new low-cost three-phase four-switch three-level zero-voltage-switching (ZVS) discontinuous-current-mode power-factor-correction boost rectifier, for short named the three-level TAIPEI rectifier, that achieves a low input-current total harmonic distortion (THD) and features ZVS of all the switches is introduced. Since in the proposed rectifier the voltage stress of the four switches is equal to one-half of the output voltage, the rectifier can utilize switches with a lower voltage rating that, generally, have lower conduction losses. To reduce the switching-frequency range and maximize the light-load efficiency, the control is implemented by a combination of variable-switching frequency and phase-shift pulse-width modulation control. Detailed design guidelines for and performance evaluation of a three-phase 6-kW prototype designed for the line-to-line voltage range from 340 $V_{{\rm RMS}}$ to 520 $V_{{\rm RMS}}$ are presented. The prototype rectifier exhibits efficiency in the 96%–98% range and achieves less than 5% input-current THD over the entire nominal input-voltage range (380–480 V_{L-L,{\rm RMS}} ) and above 50% of full load. [ABSTRACT FROM AUTHOR]

This paper is concerned with the problem of extended dissipativity-based state estimation for uncertain discrete-time Markov jump neural networks with finite piecewise homogeneous Markov chain and mixed time delays. The aim of this paper is to present a Markov switching estimator design method, which ensures that the resulting error system is extended stochastically dissipative. A triple-summable term is introduced in the constructed Lyapunov function and the reciprocally convex approach is utilized to bound the forward difference of the triple-summable term. The extended dissipativity criterion is derived in form of linear matrix inequalities. Numerical simulations are conducted to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

The stability of autonomous dynamical switched systems is analyzed by means of multiple Lyapunov functions. The stability theorems given in this paper have finite number of conditions to check. It is shown that linear functions can be used as Lyapunov functions. An example of an exponentially asymptotically stable switched system formed by four unstable systems is also given. [ABSTRACT FROM AUTHOR]

The spatial wavefunction-switched field-effect transistor (SWSFET) is one of the promising quantum well devices that transfers electrons from one quantum well channel to the other channel based on the applied gate voltage. This eliminates the use of more transistors as we have coupled channels in the same device operating at different threshold voltages. This feature can be exploited in many digital integrated circuits thus reducing the count of transistors which translates to less die area. The simulations of basic sequential circuits like SR latch, D latch and flip flop are presented here using SWSFET based logic gates. The circuit model of a SWSFET was developed using Berkeley short channel IGFET model (BSIM 3). [ABSTRACT FROM AUTHOR]

In high-field magnetic resonance imaging, the radio frequency wavelength within the human body is comparable to anatomical dimensions, resulting in B1 inhomogeneity and nonuniform sensitivity patterns. Thus, this relatively short wavelength presents engineering challenges for RF coil design. In this study, a bilateral breast coil for 1H imaging at 7 T was designed and constructed using forced-current excitation. By forcing equal current through the coil elements, we reduce the effects of coupling between the elements to simplify tuning and to ensure a uniform field across both breasts. To combine the benefits of the higher power efficiency of a unilateral coil with the bilateral coverage of a bilateral coil, a switching circuit was implemented to allow the coil to be reconfigured for imaging the left, right, or both breasts. [ABSTRACT FROM PUBLISHER]

In this paper, we compare the performances of FinFETs, lateral gate-all-around (GAA) FETs, and vertical GAAFETs (VFETs) at 7-nm node dimensions and beyond. Comparison is done at ring oscillator level accounting not only for front-end of line devices but also for interconnects. It is demonstrated that FinFETs fail to maintain the performance at scaled dimensions, while VFETs demonstrate good scalability and eventually outperform lateral devices both in speed and power consumption. Lateral GAAFETs show better scalability with respect to FinFETs but still consume 35% more energy per switch than VFETs if made under 5-nm node design rules. [ABSTRACT FROM AUTHOR]

This paper studies adaptive control of switched nonlinearly parameterized cascade systems. No solvability of the adaptive control problem for subsystems is required. By exploiting the multiple Lyapunov functions method and the parameter separation technique and the tool of adding a power integrator, we develop a new switched adaptive control approach for the explicit construction of adaptive controllers of subsystems and a proper switching law that solves the adaptive stabilization problem. A key feature of the proposed adaptive controllers is its switched property, namely, each subsystem has its individual update law. A two-inverted pendulum as a practical example is also provided to demonstrate the effectiveness of the proposed design method. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The bridge-type fault current limiter has the capability of controlling the fault current by controlling the DC reactor current. This fault current limiter is mainly composed of a diode bridge rectifier and a DC reactor. To achieve this capability, a resistor parallel with a semiconductor switch has been used in series with a DC reactor. For this fault current limiter, a control scheme is proposed that uses the DC reactor current as a control variable to improve transient stability of the model power system without measuring any parameters of system. In this article, an analytical and simulation study was conducted on a one-machine infinite-bus system including a bridge-type fault current limiter and the proposed control scheme. Simulation results show that by controlling the turn-on and turn-off times of the switch,i.e., the switching technique, the proposed fault current limiter can not only limit the fault current but also absorb the accelerating energy of the generator, thereby improving power system transient stability. The rotor velocity, maximum output power of the generator, and critical fault clearing time are studied in this article to evaluate the effects of the proposed fault current limiter on power system transient stability. [ABSTRACT FROM PUBLISHER]

The ferroelectric switchable diode induced resistive switching behavior at low temperature has been investigated in the epitaxial BiFeO3 (BFO) thin films. The switchable diode can be tuned using a higher voltage at low temperatures. The diode barrier is determined to be ~0.55 eV at the interface between BFO and electrode. The resistive switchable barrier with respect to the ferroelectric domain switching has been systematically characterized at various low temperatures. The temperature dependent conduction and leakage mechanisms have also been identified. These results can advance our understanding of resistive switching based on ferroelectric switchable diode at low working temperatures and potentially extend the applications of memristor to a larger temperature scale. [ABSTRACT FROM AUTHOR]

The Ru-Al codoped NiO:SnO2 nanocomposite films are revealed to exhibit bipolar resistive switching. The switching mechanism is well explained by the formation/rupture of filamentary paths due to the field-induced migration of oxygen vacancies and oxygen ions. Compared with that of the undoped NiO:SnO2 film, the ON/OFF ratio of Ru-Al codoped samples is largely improved. This is ascribed to the increased content of oxygen vacancies and trapped states between the equilibrium Fermi level and conduction band induced by the interstitial defects of Ru and Al. [ABSTRACT FROM AUTHOR]

The onset of localized current conduction during electroforming of TiO2-based resistive switching devices is investigated using a pulsed voltage method. The temperature rise at electroforming onset is found to vary from 25 to 300 °C as the pulse amplitude and the width are varied between 3-8V and 10 ns-100ms, respectively. The effective activation energy of the forming event is strongly electric field dependent and decreases from 0.7 eV at 3V to almost zero at 8V. The functional form of this dependence points toward charge trapping as the mechanism rather than oxygen vacancy motion. [ABSTRACT FROM AUTHOR]

We propose a magnetoresistive memory cell on the basis of the three dimensional nanostructure "small disk on big disk" possessing the three stable configurations of magnetization. Magnetic behavior of magnetostatically interacting nanodisks under an impact of the high frequency excitation has been studied by means of micromagnetic simulation. The movement of a vortex core in the big disk can induce a change in magnetization configuration in the small one. We prove that magnetic state variation in the double disk nanostructure can be registered by the transverse magnetoresistance measurement. [ABSTRACT FROM AUTHOR]

This paper is concerned with the problem of input-output finite-time stability (IO-FTS) for discrete impulsive switched systems with state delays. Sufficient conditions are presented for the existence of IO-FTS for such systems under the cases of certain switching, arbitrary switching, and uncertain switching. All the obtained results are formulated in a set of linear matrix inequalities (LMIs). Two numerical examples are given to illustrate the effectiveness of the proposed results. [ABSTRACT FROM AUTHOR]

Electrolytic capacitors are often used for energy buffering applications, including buffering between single-phase ac and dc. While these capacitors have high energy density compared to film and ceramic capacitors, their life is limited. This paper presents a stacked switched capacitor (SSC) energy buffer architecture and some of its topological embodiments, which when used with longer life film capacitors overcome this limitation while achieving effective energy densities comparable to electrolytic capacitors. The architectural approach is introduced along with design and control techniques. A prototype SSC energy buffer using film capacitors, designed for a 320 V dc bus and able to support a 135 W load, has been built and tested with a power factor correction circuit. It is shown that the SSC energy buffer can successfully replace limited-life electrolytic capacitors with much longer life film capacitors, while maintaining volume and efficiency at a comparable level. [ABSTRACT FROM AUTHOR]

We report on the electronic roles in filamentary-type switching of binary oxide-based resistive random access memories using ab initio calculations. We show that charge injection and removal determine the thermodynamic stability of the vacancy filament and the diffusion in the memory devices; electron injection induces the vacancy cohesion that stabilizes the filament, whereas removal of these electrons favors the vacancy isolation that destabilizes the filament; electron removal makes the energy barrier of the vacancy diffusion processes small enough to be overcome by joule heating. The vacancy cohesion-isolation processes are induced by charge injection and removal that leads to occupation of the bonding-like electron states, which can be controlled by shifting the system Fermi level via an applied voltage during memory operation. The vacancy cohesion-isolation phase transition upon charge injection and removal is thus one of the main factors that govern resistive switching. Based on the physics, we propose three-layer stack structures for further improvement of the memory characteristics. [ABSTRACT FROM AUTHOR]

The design and characterization in high-voltage (HV)-CMOS technology of an innovative intelligent power switch (IPS) for harsh automotive applications is proposed in this paper. To safely handle the ordinary and extraordinary automotive electrical and environmental conditions, a systematic design flow is followed: several design solutions are presented at the architectural and circuital level, integrating on-chip self-diagnostic capabilities and full protection against the high voltage and reverse polarity, the effects of wiring parasitics, and the over-current and over-temperature phenomena. Moreover, the current slope and soft start integrated techniques ensure a low electromagnetic interference, and the IPS is also configurable to efficiently drive different interchangeable loads. The innovative IPS has been implemented in a 0.35-\mu\m HV-CMOS technology and has been embedded in mechatronic third generation brush-holder regulator system-on-chip for an automotive alternator. The electrical simulations and experimental characterization and the testing at component and on-board system levels prove that the proposed design allows a compact and smart power switch realization facing the harshest automotive conditions. [ABSTRACT FROM AUTHOR]

This paper presents a digital current regulator for H-bridge pulsewidth modulation (PWM) converters, whose sampling frequency equals quadruple of the switching frequency. The current regulator detects the ac current and manipulates the volt- age reference not only at the upper and lower peaks of the PWM triangle carrier but also at its zero crossings. This paper theoretically discusses the switching sequence of the H-bridge PWM converter, and reveals the amount of the voltage error and the condition where the voltage error occurs. A modified deadbeat current regulator is proposed to suppress the current oscillation induced by the voltage error, based on the theoretical analysis. Experimental results are shown to verify the control performance of the proposed current regulator. Moreover, a proposed current regulator is applied to a single-phase active power filter to demonstrate the effectiveness in harmonic compensation. [ABSTRACT FROM AUTHOR]

A method is proposed to guarantee bandwidth (BW) or latency of network-on-chip. This method contains three kernels: traffic classification; flit-based switching; path pre-assignment and link-BW setting. Compared with the traditional circuit-switch method, the proposed method can guarantee the latency between one flit's generation in the source node and its reception in the destination node. This method also supports a wide range of traffic types such as latency critical, low BW traffic and streaming data which only have BW requirement. Moreover, router and network interface which support the proposed method are implemented and a maximum latency formula is developed. Simulation and synthesis results show that this method can guarantee the BW and latency well and is relatively low cost. [ABSTRACT FROM AUTHOR]

The system analysis and design consideration of a zero voltage switching (ZVS) converter with series-connected transformers are presested. Based on the operational behaviour, each transformer in the adopted converter can be operated as an inductor or a transformer. Therefore no output filter inductor is needed in the adopted converter. To reduce the voltage stress of the switching device in the conventional forward converter, an active snubber based on a clamp switch and a clamp capacitor is used to recycle the energy stored in the transformer leakage. During the transition interval, the resonance based on the junction capacitance of switches and transformer leakage inductance can achieve ZVS operation of switches. The centre-tapped rectifier is used at the secondary side to achieve full-wave rectification. The operating principles, steady-state analysis and design equations of the proposed converter are provided. Finally, experimental results for a 100 W (5 V/20 A) prototype circuit are provided to verify the converter performance. [ABSTRACT FROM AUTHOR]

Discusses the fault-tolerant routing switcher topologies for centralized distribution systems. Key features of router architectures for a broadcast facility; Building of nonblocking routers that use reduced numbers of crosspoint elements; Failure modes; Impact block; Shared memory switching with expansion; Reliable plant implementations; Use of patch bays; Signal interleave techniques; Characteristics of reliable, resilient routers.

This paper explores theories on designing optimal multipoint interconnection structures, and proposes a simple switch box design scheme which can be directly applied to field programmable gate arrays (FPGAs), switch box designs, and communication switching network designs. We present a new hyper universal switch box designs with four sides and W terminals on each side, which is mutable for every multipinnet-muting requirement. This new design is proved to be optimum for W = 1,...,5 and close to optimum for W ≥ 6 with 6.&3bar;W switches. We also give a formal analysis and extensive benchmark experiments on mutability comparisons between today's most well-known FPGA switch boxes like disjoint switch blocks (Xilinx XC4000 Type), Wilton's switch blocks, Universal switch blocks, and our Hyperuniversal switch boxes. We apply the design scheme to rearrangeable switching network designs targeting for applications of connecting multiple terminals (e.g., teleconferencing). Simply using a k-sided hyperuniversal switch block with a W × W crossbar attached to each side, one can build a three-stage one-sided polygonal switching network capable of realizing every multipoint connection requirement on kW terminals. Besides, due to the fine-grained decomposition property of our design scheme, the new switch box designs are highly scalable and simple on physical layout and routing algorithm implementations. [ABSTRACT FROM AUTHOR]

Presents an alternative approach for the determination of the 'OFF-ON' switching/turnover process in four-layer semiconductor devices. Summary of the two-transistor model; Use of positive feedback in explaining the mechanism of the triggering of the switching operation; Use of an open-loop gain criteria.

The erasing characteristics of Cu2O metal-insulator-metal resistive switching memory were measured on a 64 Kb memory test array. The erasing yield reaches the maximum at an optimal erasing voltage. Effective erasing requires a threshold current compliance that is higher for shorter pulse width. The erasing current and erasing power both depend strongly on the on-state before erasing, while the erasing voltage is essentially unaffected. Erasing appears to be a power-driven process, which may be related to the thermal effect of power dissipation. The experimental data and analysis suggest that erasing can be explained by field-assisted thermal emission of trapped charges. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate reversible resistance switching in a capacitorlike cell using a Ge–Sb–Te film that does not rely on amorphous-crystalline phase change. The polarity of the applied electric field switches the cell resistance between lower- and higher-resistance states, as was observed in current-voltage characteristics. Moreover, voltage pulses less than 1.25 V showed this switching within time scales of microseconds with more than 40% contrast between the resistance states. The latter are found to be nonvolatile for months. The switching could also be achieved at nanoscales with atomic force microscopy with a better resistance contrast of three orders of magnitude. [ABSTRACT FROM AUTHOR]

Microplasmas at high pressure have been the authors’ special interest for its practical relevance to the development of a switch. They concentrated on repetitive switching with a possibility to exceed the up to now known values for plasma closing switches and simultaneously maintaining a subnanosecond rise time of the switched pulses at a load. They examined several parameters for this purpose such as the electrode gap spacing, the electrode geometry, the gas type, the gas pressure, and including the applied voltage and current rating to operate these plasmas. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate precise voltage contrast image positioning for in situ electron beam (e-beam) nanolithography to integrate nanowires into suspended structures for nanoswitch fabrication. The positioning of the deflection electrodes on the nanowires can be well controlled using a precise voltage contrast image positioning technique, where the error can be minimized to about 10 nm. Using such a method, dispersed nanowires can be sandwiched between two layers of resist and suspended by one e-beam nanolithography process without any etching. The in situ e-beam nanolithography eliminates the stage movement error by preventing any movements of the stage during the nanolithography process; hence, a high precision laser stage and alignment marks on the substrate are not needed, which simplifies the traditional e-beam nanolithography process. The nanoswitches fabricated using this method show ON and OFF states with the changes of applied voltages. This simplified process provides an easy, low cost and less time-consuming route to integrating suspended nanowire based structures using a converted field emission scanning electron microscope e-beam system, which can also be customized to fabricate multi-layer structures and a site-specific nanodevice fabrication. [ABSTRACT FROM AUTHOR]