Low-Voltage Ultra-Low-Power Current Conveyor Based on Quasi-Floating Gate Transistors

The field of low-voltage low-power CMOS technology has grown rapidly in recent years; it is an essential prerequisite particularly for portable electronic equipment and implantable medical devices due to its influence on battery lifetime. Recently, significant improvements in implementing circuits working in the low-voltage low-power area have been achieved, but circuit designers face severe challenges when trying to improve or even maintain the circuit performance with reduced supply voltage. In this paper, a low-voltage ultra-low-power current conveyor second generation CCII based on quasi-floating gate transistors is presented. The proposed circuit operates at a very low supply voltage of only ±0.4 V with rail-to-rail voltage swing capability and a total quiescent power consumption of mere 9.5 µW. Further, the proposed circuit is not only able to process the AC signal as it's usual at quasi-floating gate transistors but also the DC which extends the applicability of the proposed circuit. In conclusion, an application example of the current-mode quadrature oscillator is presented. PSpice simulation results using the 0.18 µm TSMC CMOS technology are included to confirm the attractive properties of the proposed circuit

A Survey of Non-conventional Techniques for Low-voltage Low-power Analog Circuit Design

Designing integrated circuits able to work under low-voltage (LV) low-power (LP) condition is currently undergoing a very considerable boom. Reducing voltage supply and power consumption of integrated circuits is crucial factor since in general it ensures the device reliability, prevents overheating of the circuits and in particular prolongs the operation period for battery powered devices. Recently, non-conventional techniques i.e. bulk-driven (BD), floating-gate (FG) and quasi-floating-gate (QFG) techniques have been proposed as powerful ways to reduce the design complexity and push the voltage supply towards threshold voltage of the MOS transistors (MOST). Therefore, this paper presents the operation principle, the advantages and disadvantages of each of these techniques, enabling circuit designers to choose the proper design technique based on application requirements. As an example of application three operational transconductance amplifiers (OTA) base on these non-conventional techniques are presented, the voltage supply is only ±0.4 V and the power consumption is 23.5 µW. PSpice simulation results using the 0.18 µm CMOS technology from TSMC are included to verify the design functionality and correspondence with theory

ECCCII-Based Current-Mode Universal Filter with Orthogonal Control of w_o and Q

This paper presents a new current-mode current-controlled four-input five-output universal filter employing one current-controlled current conveyor (CCCII), one electronically tunable CCCII and two grounded capacitors. The proposed configuration provides lowpass, bandpass, highpass, bandstop and allpass current responses that taken from the high-output impedance terminals, which enable easy cascadability of the current-mode operation. The filter also offers both orthogonal and electronic controls of the natural frequency and the quality factor through adjusting the bias current of the CCCIIs. For realizing all the filter responses, the proposed filter does not require passive component-matching condition and both active and passive sensitivities are low. In addition, a new current-mode current-controlled single-input five-output universal filter can be achieved by using an additional multiple-output minus-type CCCII. The proposed filter is simulated using PSPICE simulations to confirm the theoretical analysis

Voltage-Mode Multifunction Biquadratic Filters Using New Ultra-Low-Power Differential Difference Current Conveyors

This paper presents two low-power voltage-mode multifunction biquadratic filters using differential difference current conveyors. Each proposed circuit employs three differential difference current conveyors, two grounded capacitors and two grounded resistors. The low-voltage ultra-low-power differential difference current conveyor is used to provide low-power consumption of the proposed filters. By appropriately connecting the input and output terminals, the proposed filters can provide low-pass, band-pass, high-pass, band-stop and all-pass voltage responses at high-input terminals, which is a desirable feature for voltage-mode operations. The natural frequency and the quality factor can be orthogonally set by adjusting the circuit components. For realizing all the filter responses, no inverting-type input signal requirements as well as no component-matching conditional requirements are imposed. The incremental parameter sensitivities are also low. The characteristics of the proposed circuits are simulated by using PSPICE simulators to confirm the presented theory

Hybrid Takagi‐Sugeno Fuzzy FED PID Control of Nonlinear Systems

The new method of proportional‐integral‐derivative (PID) controller is proposed in this paper for a hybrid fuzzy PID controller for nonlinear system. The important feature of the proposed approach is that it combines the fuzzy gain scheduling method and a fuzzy fed PID controller to solve the nonlinear control problem. The resultant fuzzy rule base of the proposed controller contains one part. This single part of the rules uses the Takagi–Sugeno method for solving the nonlinear problem. The simulation results of a nonlinear system show that the performance of a fed PID Hybrid Takagi‐Sugeno fuzzy controller is better than that of the conventional fuzzy PID controller or Hybrid Mamdani fuzzy FED PID controller

A Novel Current-Mode Full-Wave Rectifier Based on One CDTA and Two Diodes

Precision rectifiers are important building blocks for analog signal processing. The traditional approach based on diodes and operational amplifiers (OpAmps) exhibits undesirable effects caused by limited OpAmp slew rate and diode commutations. In the paper, a full-wave rectifier based on one CDTA and two Schottky diodes is presented. The PSpice simulation results are included

SME in Syria: Analysing - Management - Import Export

Tato disertacni prace je venovana tematu malych a strednich podniku v Syrii: Analyza - Management - Dovoz a Vyvoz. Syrsky trh je mezinarodnimu obchodovani pomerne otevreny. Obchodni smlouvy byly podepsany jiz s nekolika zememi. V rijnu 2004 Syrie podepsala take smlouvu o spolupraci s evropskou unii. Tato prace popisuje a analyzuje male a stredni podniky v Syrii pro pot.eby mezinarodniho obchodu i Syrskeho trhu. Ziskane vysledky jsou zpracovany a na jejich zaklade jsou stanovena doporuceni pro firmy hodlajici dovazet ci vyvazet do /ze Syrie.This dissertation is devoted to “Small and Medium Sized Enterprises (SME) in Syria: Analysing - Management - Import Export” for doctoral study program at Faculty of Business and Management. Syrian market is quite open to international trade. Free-trade agreements have been signed with many countries. Syria also signed an Association Agreement with the EU in October 2004. This work describes and analyses the small and medium sized Syrian Enterprises for international trade and the Syrian market as well. The obtained results will be discussed and on the basis of it recommendation for the companies planning to import export goods from / to Syria will be stated.

Attentional Modulation of Early ERP Components in Response to Faces: Evidence From the Attentional Blink Paradigm

The attentional blink (AB) is a transient attentional deficit that occurs when two stimuli that must both be detected are presented within an interval of less than 500ms. Event-related potential (ERP) investigations have suggested that the AB affects a specific component, the P3, which is suppressed when targets are blinked. In view of the link between the P3 and working memory, it has been suggested that the AB might be due to the inability of the blinked target to access working memory. Interestingly, it seems that faces, due to their saliency, might escape the AB effect when cross-category detection is required (i.e., when the targets are composed of faces versus other categories of stimuli). In the present study we investigated this phenomenon in an event-related potential (ERP) study using upright and inverted faces as targets. In a first task, the participants were asked to identify two successive targets, the first composed of geometric shapes and the second of upright or inverted faces. A second control task, identical to the first was also performed, in which only the second targets had to be identified in order to compare ERPs. ERPs and scalp topographies of physically identical sequences of events, differing only by the attentional involvement, were thus compared. Behavioural results showed that faces indeed escape the AB while inverted faces do not. However, the electrophysiological findings showed that when attention was engaged in a previous stimulus (at the shortest lag times), both upright and inverted faces showed a decreased amplitude in the 150-260ms time period, in addition to a lower P3. At longer lags, when the AB was no longer observed, no ERP differences were found. Our data demonstrate that, although faces escape the attentional blink, previous attentional involvement occurs much earlier than described for other categories of stimuli. This suggests that faces are subjected to an early selection which might allow rapid re-allocation of attention to the stimulus if it is deemed meaningfu

Cross-sectional investigation of mycological diagnosis challenges in Saudi Arabia

BackgroundThe global incidence of fungal infection has increased dramatically over the last two decades. Fungal diseases threaten both immunocompetent, and immunocompromised patients. The current fungal diagnostics status in Saudi Arabia needs to be evaluated, especially with the increase of the immunosuppressed population. This cross-sectional study investigated the gaps in mycological diagnosis on a national level.Materials and methodsThe call interview questionnaire responses were collected to evaluate the demand for fungal assays, diagnostic methods’ quality, and mycological expertise of laboratory technologists in both public and private medical intuitions. The data were analyzed using (IBM SPSS ® software version 22.0).ResultsA total of 57 hospitals from all Saudi regions participated in the questionnaire; however, only 32% received or processed mycological samples. Most participants were from the Mecca region (25%), Riyadh region (19%), and Eastern region (14%). The top fungal isolates identified were Candida spp., Aspergillus spp., and dermatophyte. Fungal investigation is highly requested by intensive care, dermatology, and obstetrics and gynecology units. Most laboratories rely on fungal culture and microscopic examination, which mostly identify Candida to the genus level, and use 37°C incubators for culture (67%). Antifungal susceptibility testing (AST) and serological and molecular methods are rarely performed and mostly outsourced. Using accurate identification and AST are the primary factors to improve fungal diagnosis in respect to turnaround time and cost. The three major obstacles identified were availability of facility (47%), reagents and kits (32%), and good training (21%).ConclusionsThe results indicated that fungal diagnosis demand was relatively higher in high-population regions. This study highlighted the gaps in fungal diagnostics reference laboratories to encourage their improvement in Saudi hospitals

Allosteric inhibition enhances the efficacy of ABL kinase inhibitors to target unmutated BCR-ABL and BCR-ABL-T315I

Background: Chronic myelogenous leukemia (CML) and Philadelphia chromosome-positive (Ph+) acute lymphatic leukemia (Ph + ALL) are caused by the t(9;22), which fuses BCR to ABL resulting in deregulated ABL-tyrosine kinase activity. The constitutively activated BCR/ABL-kinase "escapes" the auto-inhibition mechanisms of c-ABL, such as allosteric inhibition. The ABL-kinase inhibitors (AKIs) Imatinib, Nilotinib or Dasatinib, which target the ATP-binding site, are effective in Ph + leukemia. Another molecular therapy approach targeting BCR/ABL restores allosteric inhibition. Given the fact that all AKIs fail to inhibit BCR/ABL harboring the 'gatekeeper' mutation T315I, we investigated the effects of AKIs in combination with the allosteric inhibitor GNF2 in Ph + leukemia. Methods: The efficacy of this approach on the leukemogenic potential of BCR/ABL was studied in Ba/F3 cells, primary murine bone marrow cells, and untransformed Rat-1 fibroblasts expressing BCR/ABL or BCR/ABL-T315I as well as in patient-derived long-term cultures (PDLTC) from Ph + ALL-patients. Results: Here, we show that GNF-2 increased the effects of AKIs on unmutated BCR/ABL. Interestingly, the combination of Dasatinib and GNF-2 overcame resistance of BCR/ABL-T315I in all models used in a synergistic manner. Conclusions: Our observations establish a new approach for the molecular targeting of BCR/ABL and its resistant mutants using a combination of AKIs and allosteric inhibitors