Aneta Prijic

University of Niš | NIS · Department of Microelectronics

Contribution: Impact assessment of the practice-oriented course for high school students on their later academic achievements, described in the context of long-term efforts to improve electronic engineering studies’ quality. The article highlights the importance of outreach and extracurricular activities and cooperation with the IEEE in these effo...

In this paper, the effects of successively applied static/pulsed negative bias temperature (NBT) stress and irradiation on commercial p-channel power vertical double-diffused metal-oxide semiconductor (VDMOS) transistors are investigated. To further illustrate the impacts of these stresses on the power devices, the relative contributions of gate ox...

This paper presents a spatial SPICE model of a wireless sensor network node that enables simulation of performances in the steady-state and time-domain. The model includes constructive non-electrical parts of the node and a thermoelectric generator employing the thermoelectric effects. The simulation results are compared with the experiment to vali...

This paper reports results of the transient modeling of thermoelectric cooling/heating modules as power generators with the aim to select preferable ones for use in thermal energy harvesting wireless sensor network nodes. A study is conducted using the selected commercial thermoelectric generators within the node of a compact design with aluminum P...

Many sensors exhibit nonlinear dependence between their input and output variables and specific techniques are often applied for the linearization of their transfer characteristics. Some of them include additional analog circuits, while the others are based on different numerical procedures. One commonly used software solution is Progressive Polyno...

This paper considers the effects of the ambient temperature and unducted air flow on the voltage generated by a thermoelectric generator used to power wireless sensor network node. Structure of the node is simulated using a fully coupled numerical electro--thermal model with convective correlations. Results show that the effect of the ambient tempe...

The mechanisms responsible for the effects of consecutive irradiation and negative bias temperature (NBT) stress in p-channel power vertical double-diffused MOS (VDMOS) transistors are presented in this paper. The investigation was performed in order to clarify the mechanisms responsible for the effects of specific kind of stress in devices previou...

In this paper we provide an overview of instabilities observed in commercial power VDMOSFETs subjected to irradiation, NBT stress, and to consecutive exposure to them. The results have indicated that irradiation of previously NBT stressed devices leads to additional threshold voltage shift, while NBT stress effects in previously irradiated devices...

Thermal energy harvesting systems commonly exploit thermoelectric generators as power sources. This paper describes characterization of commercial thermoelectric cooling/heating modules, with the aim to select preferable ones for use as generators in energy harvesting wireless sensor nodes. Performed numerical electro–thermal analysis considers gen...

In this paper the results of characterization and modeling of passive electronic devices (capacitors and inductors) have been presented. The experimental results obtained using RF impedance analyzer have been discussed, and based on them, parameters of equivalent circuits have been determined using analytical model. Approximate functions for parasi...

This paper introduces a new experimental approach allowing to investigate the recoverable and permanent components in commercial p-channel power VDMOSFETs subjected to negative bias temperature (NBT) stressing. In many applications, devices can be used in multiple modes, which include application of static or pulsed gate voltages at different stage...

This paper reports the design of a photovoltaic energy harvesting device used as telemetry node in wireless sensor networks. The device draws power from the small solar cell, stores it into the primary energy buffer and backup supercapacitor, collects measured data from various sensors and transmits them over low power radio link at 868 MHz. Its de...

Our recent research of the effects of pulsed bias NBT stressing in p-channel power VDMOSFETs is reviewed in this paper. The reduced degradation normally observed under the pulsed stress bias conditions is discussed in terms of the dynamic recovery effects, which are further assessed by varying the duty cycle ratio and frequency of the pulsed stress...

In this paper the results of modeling and simulation of radiation stress effects in p-channel power VDMOSFET transistor have been presented. Based on measured results, the threshold voltage shifts as a function of absorbed dose and gate voltage during radiation stress have been modeled and implemented in the PSPICE model of the IRF9520 transistor....

This paper discusses the application of flat panel reflectors in conjunction with photovoltaic cell used to power wireless sensor node. The aim of the reflectors is to increase the indoor ambient light energy harvesting efficiency, especially under low illumination levels (<200 lx). The benefit of the reflectors usage is in the reduction of the nod...

In this study we investigate the dynamic recovery effects in IRF9520 commercial p-channel power vertical double diffused metal–oxide semiconductor field-effect transistors (VDMOSFETs) subjected to negative bias temperature (NBT) stressing under the particular pulsed bias. Particular values of the pulsed stress voltage frequency and duty cycle are c...

In this paper the results of characterization and modelling of capacitors have been presented. The experimental results obtained using RF impedance analyzer have been discussed, and based on them, parameters of equivalent circuits have been determined using analytical model. Approximate functions for parasitic elements of the device have been propo...

In this study, which is aimed at assessing a possible relationship between the recoverable and permanent components of negative bias temperature instability (NBTI) degradation, we investigate NBTI in commercial IRF9520 p-channel VDMOSFETs (vertical double diffused MOSFETs) stressed under particular pulsed bias conditions by varying the pulse on-tim...

his paper reports the design of a self-powered telemetric wireless sensor node for temperature measurement. The device is realized with a conventional off-the-shelf thermoelectric generator as a power source. It is sandwiched between two aluminum core printed circuit boards (PCBs). One board is exposed to the heat source and has the role of a heat...

In this paper the results of modeling and simulation of NBTI effects in p-channel power VDMOS transistor have been presented. Based on the experimental results, the threshold voltage shifts and changes of transconductance during the NBT stress have been modeled and implemented in the PSPICE model of the IRF9520 transistor. By predefining the thresh...

This paper highlights some crucial design challenges of Machine–to– Machine (M2M) systems. The focus is on the cellular based, wireless wide area network systems. Design of M2M terminals, used as wireless sensor nodes, is covered in detail, including the criteria for selecting appropriate core and hardware peripherals. Discussion is extended to mod...

In this paper we report on the use of a cost-effective stress and measurement setup for investigations of NBTI in commercial p-channel power VDMOS transistors IRF9520. The effects of stress voltage and temperature under both static and pulsed bias stress conditions are briefly discussed, and dynamic recovery effects are evaluated by varying the dut...

In this paper the measurement methods for dielectric constant determination in Nb/BaTiO3 ceramics have been presented. The experimental results obtained using LCR meter with dielectric test fixture and the influence of ceramic microstructure on the accuracy of methods have been discussed.

Vast majority of recent extensive investigations of Negative Bias Temperature Instability (NBT) have been focused to the related phenomena in ultrathin gate dielectric layers of SiO2, SiON, and high-k materials. However, even though the gate oxides in nanometer scale technologies have been continuously thinned down, the interest in thick oxides has...

In this study we investigate NBTI in commercial IRF9520 p-channel VDMOSFETs under both static and pulsed bias stress conditions. The pulsed voltage stressing caused generally lower shifts as compared to static stressing performed at the same temperature with equal stress voltage magnitude, as a consequence of partial recovery during the low level o...

This paper describes a printed circuit board (PCB) design course based on electromechanical workflow. The course relies on the premise that a PCB is an integral component of any electronic apparatus, along with its other electromechanical and mechanical components. To emphasize this to students, electrical and mechanical computer-aided design tools...

Threshold voltage shifts associated with negative gate bias temperature instability in p-channel power VDMOSFETs under the static and pulsed stress conditions are analysed in terms of the effects on device lifetime. The pulsed bias stressing is found to cause less significant threshold voltage shifts in comparison with those caused by the static st...

A method suitable for performing NBTI measurements on power p-channel VDMOS transistors is described. A practical implementation using simple boosting circuit for obtaining required gate stress voltage and sweep I–V measurements for the threshold voltage shift determination is presented. Experimental results are discussed in terms of the time neces...

This paper reports the design and manufacturing of a device suitable for use in command panels of industrial equipment in the place of mechanical buttons and switches. The device consists of a capacitive pressure sensor, low-cost microcontroller, current driver, and state indication LEDs. All components are embedded into multilayer printed circuit...

The effects of static and pulsed NBT stressing on threshold voltage in p-channel power VDMOSFETs are analysed, and the results are compared in terms of the effects on device lifetime. The results obtained by both “1/VG” and “1/T” models, which are used for extrapolation to normal operation voltages and temperatures, respectively, indicate the devic...

Threshold voltage instabilities induced in p-channel power VDMOSFETs by pulsed negative bias temperature stressing are presented and compared with corresponding instabilities found after the static NBT stress. Degradation observed under the pulsed stress conditions depends on the frequency and duty cycle of stress voltage pulses, and is generally l...

This paper presents the application of Architecture Analysis and Design Language (AADL) for the modeling of Machine to Machine talk (M2M) terminal. Examined terminal is used in telemetry, utilizing GSM network and GPRS/EDGE services for the data transmission. The AADL model is used to apply mapping of the embedded software to the hardware of the te...

Results of pulsed NBT stress-induced threshold voltage instabilities in p-channel power VDMOSFETs are presented and compared with static NBTI results. Optimal frequency and duty cycle ranges for application of investigated devices are proposed as well.

A design and optimization procedure for S-type thermal cutoffs is presented in this paper. This type of cutoff is widely used for thermal protection of windings in motors and transformers and in boiling systems. Cutoff temperature is determined by the melting point of the alloy which is used for breaking the electrical circuit. A method for obtaini...

This paper presents results of liquidus surface estimation of ternary Sn-Pb-Bi and Sn-Pb-In alloys applying a method which is based on the property of 3D ternary phase diagrams to form smooth surfaces in specific composition and temperature range. Standard program for solid modeling is applied for construction of liquidus surface of an alloy using...

Electric contacts of riveted type are analyzed by 3D simulation of their mechanical, electrical and thermal characteristics. Special emphasis was put on dependencies of contacts' temperatures on chosen contact material and applied load conditions. Mechanical characteristics of contacts are considered through yield stress distributions and their max...

The static dielectric constant of the heavily doped silicon at room temperature is considered. By using phosphorus as an example, the existing expression for the static dielectric constant at low temperatures is recast into a form suitable for the application at room temperature. This is done by taking into account the contribution of non-ionized i...

In this paper we present a derivation of the general equation for calculation of the minority carrier current density in silicon diode containing graded n-n+ junction. The derivation of equation applicable at all injection levels is carried out by accounting for the heavy doping effects. Applicability of derived general expression is evaluated in d...