The Design of Low Power CMOS SRAM Subsystems

The low power circuit design technique has been the trend in developing portable and smaller size electronic products, especially for communication peripherals. In the limitation on the device technology, integrated circuit design work has played an important role in performing various low power techniques. This thesis presents the design of low power Complementary Metal Oxide Semiconductor (CMOS) Static Random Access Memory (SRAM) Subsystems. CMOS technology performs much lower static power dissipation compares to other technologies. The implementation of this design by using 3.3 V supply voltage has effectively reduced the dynamic power dissipation of the circuitry. Low power is achieved by implementing 6T -memory cell. Low power techniques are also achieved on capacitance reduction by using divided word-line structure for address decoder. Finally the low power is achieved by the operating voltage reduction using current-mode sensing technique for sense amplifier with the pre-charge voltage of Vdd/2

Structural study in Highly Compressed BiFeO3 Epitaxial Thin Films on YAlO3

We report a study on the thermodynamic stability and structure analysis of the epitaxial BiFeO3 (BFO) thin films grown on YAlO3 (YAO) substrate. First we observe a phase transition of MC-MA-T occurs in thin sample (<60 nm) with an utter tetragonal-like phase (denoted as MII here) with a large c/a ratio (~1.23). Specifically, MII phase transition process refers to the structural evolution from a monoclinic MC structure at room temperature to a monoclinic MA at higher temperature (150oC) and eventually to a presence of nearly tetragonal structure above 275oC. This phase transition is further confirmed by the piezoforce microscopy measurement, which shows the rotation of polarization axis during the phase transition. A systematic study on structural evolution with thickness to elucidate the impact of strain state is performed. We note that the YAO substrate can serve as a felicitous base for growing T-like BFO because this phase stably exists in very thick film. Thick BFO films grown on YAO substrate exhibit a typical "morphotropic-phase-boundary"-like feature with coexisting multiple phases (MII, MI, and R) and a periodic stripe-like topography. A discrepancy of arrayed stripe morphology in different direction on YAO substrate due to the anisotropic strain suggests a possibility to tune the MPB-like region. Our study provides more insights to understand the strain mediated phase co-existence in multiferroic BFO system.Comment: 18 pages, 6 figures, submitted to Journal of Applied Physic

THE JOINT KINETICS OF THE LOWER EXTREMITY ASSOCIATED WITH DROP JUMP HEIGHT INCREMENTS

The purpose of this study was to identify the joint kinetics of the lower extremity associated with drop jump height increments. Sixteen subjects performed the drop jumps from the 20, 30, 40, 50 and 60-cm heights. Eleven Eagle cameras (200 Hz) and two AMTI force platforms (2000 Hz) were synchronized to collect the data. The study showed the impact was relatively larger in the higher height of drop jump. The greater joint absorption in drop jump from 40, 50 and 60-cm heights was found in the study. Moreover, subjects had greater knee and ankle absorption in drop jump during the eccentric movement. Drop jumps from 20 and 30-cm heights were advisable

A low quiescent current low dropout voltage regulator with self-compensation

This paper proposed a low quiescent current low-dropout voltage regulator (LDO) with self-compensation loop stability. This LDO is designed for Silicon-on-Chip (SoC) application without off-chip compensation capacitor. Worst case loop stability phenomenon happen when LDO output load current (Iload) is zero. The second pole frequency decreased tremendously towards unity-gain frequency (UGF) and compromise loop stability. To prevent this, additional current is needed to keep the output in low impedance in order to maintain second pole frequency. As Iload slowly increases, the unneeded additional current can be further reduced. This paper presents a circuit which performed self-reduction on this current by sensing the Iload. On top of that, a self-compensation circuit technique is proposed where loop stability is self-attained when Iload reduced below 100μA. In this technique, unity-gain frequency (UGF) will be decreaed and move away from second pole in order to attain loop stability. The decreased of UGF is done by reducing the total gain while maintaining the dominant pole frequency. This technique has also further reduced the total quiescent current and improved the LDO’s efficiency. The proposed LDO exhibits low quiescent current 9.4μA and 17.7μA, at Iload zero and full load 100mA respectively. The supply voltage for this LDO is 1.2V with 200mV drop-out voltage. The design is validated using 0.13μm CMOS process technology

Differentiation of Foot-and-Mouth Disease-Infected pigs from Vaccinated Pigs Using Antibody-Detecting Sandwich ELISA

The presence of serum antibodies for nonstructural proteins of the foot-and-mouth disease virus (FMDV) can differentiate FMDV-infected animals from vaccinated animals. In this study, a sandwich ELISA was developed for rapid detection of the foot-and-mouth disease (FMD) antibodies; it was based on an Escherichia coli-expressed, highly conserved region of the 3ABC nonstructural protein of the FMDV O/TW/99 strain and a monoclonal antibody derived from the expressed protein. The diagnostic sensitivity of the assay was 98.4%, and the diagnostic specificity was 100% for naïve and vaccinated pigs; the detection ability of the assay was comparable those of the PrioCHECK and UBI kits. There was 97.5, 93.4 and 66.6% agreement between the results obtained from our ELISA and those obtained from the PrioCHECK, UBI and CHEKIT kits, respectively. The kappa statistics were 0.95, 0.87 and 0.37, respectively. Moreover, antibodies for nonstructural proteins of the serotypes A, C, Asia 1, SAT 1, SAT 2 and SAT 3 were also detected in bovine sera. Furthermore, the absence of cross-reactions generated by different antibody titers against the swine vesicular disease virus and vesicular stomatitis virus (VSV) was also highlighted in this assay's specificit

The design of a prospective, randomized, open-labeled study to compare the efficacy of lercanidipine with amlodipine on renal function in hypertensive patients aged at least 55 years (LEADER study)

AbstractBackgroundAlthough all classes of antihypertensive treatment can successfully reduce morbidity and mortality of cardiac pathology, prevention of target organ damages is of great importance beyond blood pressure lowering. Unlike most dihydropyridines, lercanidipine dilates both afferent and the efferent arterioles of nephrons, so it may provide renoprotective effects, which other CCBs may not have. The main purpose of this study is to compare the renoprotective effect of lercanidipine and amlodipine among hypertensive people aged 55years and older with newly diagnosed hypertension or those who were treatment-naïve for one month.MethodsThe study is a prospective, open-labelled, randomized, controlled trial to enrol 232 hypertensive patients aged ≥55 years. Subjects will be randomized into lercanidipine arm (10–20mg/day) and amlodipine arm (5–10mg/day) by 1:1 ratio. The dosage can be up-titrated to 20mg/day (lercanidipine group) and 10mg/day (amlodipine group), respectively, at week 4 or any following visit thereafter. Efficacy and safety data will be collected at week 4, 12 and 24 by evaluating the blood pressure lowering, estimated glomerular filtration rate, creatinine clearance, and urine albumin-creatinine ratio.ConclusionsThe reno-protective effects of new generation of CCBs such as lercanidipine administered to patients with hypertension are not investigated well. After all, this study will bring benefit to older patients who need drugs with both excellent anti-hypertensive and reno-protective efficacy. And the results will be provided for future treatment guideline of elder population in Taiwan

A low power bandgap voltage reference for low-dropout regulator

A low power Bandgap Voltage Reference (BGR) is designed to supply a voltage reference for a low voltage Low-Dropout Regulator (LDO). This bandgap design consists of a bandgap core circuit, an output stage and a start-up circuit. The output of the bandgap adopted sub-1V voltage reference through the output stage circuit. The bandgap is simulated using 0.13 μm CMOS process. This BGR circuit provides voltage reference of 64mV± 1mV over-25°C to 120°C temperature range. The power supply of this BGR circuit is 1.20 V and the total current is 20 μA, thus resulting a low total power consumption of 24μW. The total layout area for this bandgap design is 66μm × 100μm

Constitutive behavior of as-cast A356

The constitutive behavior of aluminum alloy A356 in the as-cast condition has been characterized using compression tests performed over a wide range of deformation temperatures (30-500{\deg}C) and strain rates (\approx0.1-10 /s). This work is intended to support the development of process models for a wide range of conditions including those relevant to casting, forging and machining. The flow stress behavior as a function of temperature and strain rate has been fit to a modified Johnson-Cook and extended Ludwik-Hollomon expression. The data has also been assessed with both the strain-independent Kocks-Mecking and Zener-Hollomon frameworks. The predicted plastic flow stress for each expression are compared. The results indicate that the extended Ludwik-Hollomon is best suited to describe small strain conditions (stage III hardening), while the Kocks-Mecking is best employed for large strain (stage IV). At elevated temperatures, it was found that the Zener-Hollomon model provides the best prediction of flow stress.Comment: 34 pages, 12 figure