Low Dropout Research Articles

A Frequency-Tunable Fractional-N PLL for High-Energy Physics Experiments

A frequency tunable phase-locked loop (PLL) applied in high energy particle detector has been developed. In order to achieve high detection efficiency, high requirements are promoted for on-chip clock in CMOS pixel sensors, which requires high precision and low power consumption for the PLL. The proposed PLL employs a fractional-N frequency division structure. An LC voltage-controlled oscillator (LC-VCO) is used to generate the local clock. A third-order MASH sigma-delta (Σ - Δ) modulator is used to alleviate the quantization noise introduced by the fractional-N frequency divider. In order to further reduce the phase noise, pre-set and post-set binary frequency dividers are employed. In the prototype chip a low dropout regulator (LDO) is integrated to suppress the power supply noise. The PLL was designed and fabricated in a 180 nm CMOS process. It costs an area of 1.29 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and a power of 8.1 mW at a 1.8 V power supply. The measured output frequency range is 400 - 530 MHz with the reference frequency of 25 - 35 MHz. The RMS jitter, integrated from 100 kHz to 100 MHz, is 4.8 ps at 526 MHz. The in-band spur is less than -61 dBc, and the phase noise at 1 MHz frequency offset is less than -113 dBc/Hz.

Exploring the Influence of Teacher Qualifications, Classroom Size, Student Age, and Parental Involvement on High School Drop Out Rates in Sukabumi Regency

The purpose of this study was to explore the influence of teacher qualifications, classroom size, student age, and parental involvement on high school dropout rates in Sukabumi Regency. Using data from a survey of high school students in the region, multiple regression analysis was used to examine the relationships between these predictor variables and dropout rates. The results showed that all four predictor variables were significant predictors of dropout rates, with teacher qualifications and student age having the strongest influence. Specifically, having a teaching degree and license, having less than five years of teaching experience, being between the ages of 18 and 20, and larger class sizes were associated with higher dropout rates, while regular communication with teachers was associated with lower dropout rates. These findings suggest that efforts to improve teacher qualifications, reduce class sizes, and increase parental engagement and communication could help reduce high school dropout rates in Sukabumi Regency.

A feed-forward compensated FVF LDO regulator with no on-chip compensation capacitors

This paper proposes a capacitor-free Flipped Voltage Follower (FVF) Low Dropout (LDO) regulator. To stabilize the feed-back loop, the proposed multi-stage FVF LDO regulator does not require a Miller compensation capacitor or physical resistor. A capacitor-free internal structure improves closed-loop bandwidth while saving area in the LDO regulator. In this work, a large feed-forward transconductor (gmf) is proposed, which generates a strong left-half-plane (LHP) zero while consuming a small bias current. The large feed-forward transconductor boosts the LDO regulator’s DC gain and bandwidth. The proposed FVF LDO regulator is implemented in standard 130nm CMOS technology and achieves a unity gain frequency of more than 35 MHz while consuming a total quiescent current of 97μA. The proposed FVF LDO regulator has an active area of 0.0054mm2, which is less than many other LDO regulators that have been reported.

Glaucoma and aging: therapeutic difficulties experienced by the elderly

Introduction: Glaucoma is a public health problem among chronic-degenerative visual diseases due to its high incidence and for causing disability. Thus, the Glaucoma Patient Assistance Program was created to improve follow-up and avoid bleak prognoses. Objectives: to analyze the difficulties of the elderly in the use of eye drops for the treatment of glaucoma.Methods: an exploratory research was carried out where the population was composed of elderly patients with glaucoma treated at the Integrated Unit of Ipiranga linked to Basic Care in District III of João Pessoa-PB, a questionnaire was the instrument for data collection for the 61 participants. Results: it was found that 38 (62.3%) %) of the participants , 53 (87%) received 1-2 minimum wages, and 23 (37.7%) studied only until primary school. As for administration, 37 (60.7%) had no problems remembering if they had already used the eye drops, 39 (63.9%) had no difficulty using it, and 34 (55.7%) were unable to follow its use in the basic assistance. Conclusion: respondents have their obstacles to medication adherence regardless of the disease, the lack of follow-up in basic care only adds another one, so that’s why educating them would enable lower dropout rates and better prognoses.

Design and Simulation of Low Dropout, Low Power Capless Linear Voltage Regulator

This paper demonstrates a low power, frequency compensated with on-chip capacitor, low dropout linear voltage regulator. The proposed low dropout regulator (LDO) delivers a constant output voltage of 2.4[Formula: see text]V for an input range of 2.5–6.8[Formula: see text]V. A minimal drop of 2[Formula: see text]mV and 20[Formula: see text]mV was observed at no load and full load output current of 0 A to 100[Formula: see text]mA, respectively. LDO is realized by a high-gain two-stage error amplifier, internally compensated by passive a high-pass filter to achieve stability over a load current range of 0–100[Formula: see text]mA without occupying as much area as an active high-pass filter. The LDO presented requires a bias current of 10[Formula: see text]mA with a reference voltage of 1.5[Formula: see text]V and is designed in 180-nm technology.

PRO: Is liver organ allocation with MMaT-3 appropriate prioritization for patients with liver cancer?

PRO: Is liver organ allocation with MMaT-3 appropriate prioritization for patients with liver cancer?

A 64-MHz 2.15-µW/MHz On-Chip Relaxation Oscillator with 130-ppm/°C Temperature Coefficient

This paper presents a 2.15 µW/MHz at the frequency of 64 MHz relaxation oscillator with a dynamic range of frequency from 47.5 MHz to 80 MHz. To reduce the power consumption and improve energy efficiency, this work employs only one comparator and one capacitor to generate the output clock in comparison with conventional relaxation oscillator structures. A total of 50% ± 5% of the duty cycle is obtained for the output clock by implementing an auxiliary comparator. The proposed relaxation oscillator uses the output voltages of an external low-dropout (LDO) voltage and bandgap reference (BGR) for the required supply and reference voltages, respectively. Two current sources are implemented to provide the required currents for trimming the output frequency and driving the comparators. Measurement results indicate that the relaxation oscillator achieves a temperature coefficient (TC) of 130 ppm/°C over a wide temperature range from −25 °C to 135 °C at the frequency of 64 MHz. The relaxation oscillator consumes 115 µA of current at the frequency of 64 MHz under a low-dropout (LDO) voltage of 1.2 V. The proposed relaxation oscillator is analyzed and fabricated in standard 90 nm complementary metal-oxide semiconductor (CMOS) process, and the die area is 130 µm × 90 µm.

TACCO unifies annotation transfer and decomposition of cell identities for single-cell and spatial omics

Transferring annotations of single-cell-, spatial- and multi-omics data is often challenging owing both to technical limitations, such as low spatial resolution or high dropout fraction, and to biological variations, such as continuous spectra of cell states. Based on the concept that these data are often best described as continuous mixtures of cells or molecules, we present a computational framework for the transfer of annotations to cells and their combinations (TACCO), which consists of an optimal transport model extended with different wrappers to annotate a wide variety of data. We apply TACCO to identify cell types and states, decipher spatiomolecular tissue structure at the cell and molecular level and resolve differentiation trajectories using synthetic and biological datasets. While matching or exceeding the accuracy of specialized tools for the individual tasks, TACCO reduces the computational requirements by up to an order of magnitude and scales to larger datasets (for example, considering the runtime of annotation transfer for 1 M simulated dropout observations).

Student Athletes’ Causal Attributions for Sport and School Achievement in Relation to Sport Dropout and Grade Point Average

The present study longitudinally examined stability and change in the attributional profiles of Finnish student athletes (n = 391) in upper secondary sport schools. Moreover, it examined the extent to which these profiles, and changes in them, were associated with athletes' level of sport competition and school achievements and dropouts at the end of upper secondary sport school. Using latent profile analysis, five different and highly stable attributional profiles were identified for student athletes: (a)depressive (6.9%), (b)athletic self-serving (23.0%), (c)average (16.4%), (d)learned helplessness (30.9%), and (e)responsible (22.8%). The results further showed that over the 3-year study period, the responsible attributional style, wherein individuals take responsibility for successes and failures, predicted student athletes' subsequent high grade point average and low sport dropout rates even after controlling for the impacts of their earlier grade point average, gender, and type of sport.

Bandgap reference, temperature sensor and low drop-out regulator circuits monolithic sensors in TPSCo 65 nm ISC technology

With Inner Tracking System v3 (ITS3), the ALICE experiment is pursuing a wafer-scale Monolithic Active Pixel Sensor (MAPS). The chip is being developed in TPSCo 65 nm ISC technology which is under study in the framework of CERN EP R&D on monolithic sensors for High Energy Physics (HEP) applications. This contribution presents designs and measurement results of building blocks needed for this chip, in particular bandgap references and temperature sensors. In addition, simulation results of the design of Low Drop-out Regulator (LDO) to be submitted for the next prototyping run will be discussed.

Temperature-Insensitive Ka-Band Transceiver With Ultralow-Noise Self-Calibrated Low Dropout Regulator in 65-nm CMOS

This article proposes a Ka-band transceiver with an integrated local oscillator (LO) generator and multiple low dropout regulators (LDOs) to eliminate the strict requirements to the external power supply network. The proposed self-calibrated LDO eliminates the use of a bandgap reference circuit and its large flicker noise contribution in traditional power regulators to achieve ultralow-noise performance. The output of the proposed LDO is self-calibrated with temperature and process variations by autoconfiguring the feedback coefficient through a digital loop to guarantee the stable performance of its loaded high-speed circuits. The stable gain and output power of the transceiver with temperature variation are achieved by on-chip multiple self-compensation schemes, which include a self-sensing LDO for the power amplifier, a constant- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$G_{\!m}$ </tex-math></inline-formula> bias circuit for the amplification stages, and the temperature-compensated intermediate-frequency amplifiers (TC IFAs) with proportional-to-absolute-temperature (PTAT) gain to further compensate for the gain deviation caused by the second-order effect and large-signal performance difference. Implemented in 65-nm CMOS technology, measurements indicate that the output noise of the proposed LDO is as low as 15 nV/sqrt (Hz) at 10-kHz offset and the integrated power network greatly reduces the noise influence on the LO signal compared with the traditional bandgap-referenced LDO. Furthermore, due to the adoption of the proposed temperature compensation scheme, the small-signal gains of the receiver and transmitter only fluctuate by 1.1 and 1.3 dB from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$- 40\,\,^{\circ }\text{C}$ </tex-math></inline-formula> to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$85~^{\circ }\text{C}$ </tex-math></inline-formula> , respectively, and the output saturated power of the transmitter varies by 0.7 dBm over the entire temperature range.

Overview of Cardiac Rehabilitation following post-acute myocardial infarction in European Society of Cardiology member countries.

Cardiovascular disease (CVD) is still a leading cause of death and morbidity in Europe and must be addressed through approaches beyond therapeutic interventions and pharmacological management. Cardiac rehabilitation (CR) is a comprehensive, individualized, and patient-tailored programme, comprising multidisciplinary interventions. Despite its clinical benefits, cost-effectiveness, and existing guidelines, CR uptake in Europe remains suboptimal and detailed information on its current state is lacking. This centralized pan-European study (Overview of Cardiac Rehabilitation-OCRE) aimed to characterize and advance the knowledge about European Society of Cardiology (ESC) affiliated national CR settings. An online survey about provision and quality indicators from CR was sent to the network of National CVD Prevention Coordinators of ESC member states, whose answers were supported by published evidence and/or national experts. The OCRE study had a high participation rate (82%). Current positive aspects of CR include low dropout rates and short average start time after myocardial infarction, as well as public funding being standard practice. However, the uptake rate and average duration of CR are still suboptimal, and several countries lack CR mandatory rotation in Cardiology training, guidance documents, national accreditation, and electronic database registries. We also found several barriers to CR guideline implementation, at patient, staff, and healthcare levels. This study provides a comprehensive characterization of CR in Europe, generating important insight on the current provision and quality of CR in Europe, highlighting its sucesses and shortcomings, and discussing important strategies to overcome current obstacles.

A low-ripple efficiency-improvement switched-capacitor boost converter for battery-supplied low-noise applications

This paper presents a on-demand switch-on modulation (DSM) switched-capacitor charge pump (SCCP) for battery-supplied low-noise Internet-of-Things (IoT) devices. In the proposed technique, SCCP consists of two same submodules achieving 1.5X and 2X conversion ratios and the charge–discharge switches in CP core are split into parallel structures with binary-sized unit switches to adjust the charging current on-demand to improve the power conversion efficiency. To further reduce the output ripple under all load conditions, a novel two-step pulse skip modulation (PSM) ripple suppression technique is designed. The startup ripple is minimized by the proposed one-by-one startup circuit to reduce system power loss. The proposed DSM SCCP was fabricated using a 55 nm CMOS process to boost a single battery voltage (from 1.2 V to 1.5 V) up to 1.95 V. With another on-chip implemented low-dropout (LDO) regulator, a low-noise output of 1.73 V can be obtained by the low noise processing boost converter circuit. The measurement results demonstrate that the minimum CP ripple of 9.5 to 15.5 mV is achieved for 0 to 10 mA system load, respectively. Finally, a peak power conversion efficiency of 94.2% and 84.8% is realized for the proposed DSM SCCP and low noise processing boost converter circuit, respectively.

Design Thinking as an Auxiliary Tool for Educational Robotics Classes

The dynamic spread of 3D printing technologies and open-source electronics prototyping platforms has significantly enriched the diversity of instruments used within educational robotics (ER) settings. An active, low-entry-level community offering ready-to-use libraries for a broad variety of devices assists in the development of quite sophisticated projects. However, the flipside of the coin is represented by the current research findings, which reveal that students’ interest in science, technology, engineering and mathematics (STEM) subjects has declined across Europe, as manifested in difficulties when approaching scientific topics and dealing with problems and phenomena studied from a multidisciplinary perspective. Consequently, a significant percentage of youths are at risk of social exclusion due to the direct relationship between low academic achievements and school dropout. Moreover, learners lack guidance in applied and life-context skills, such as creative thinking, problem solving, and collaboration, which highlights the need to introduce innovative pedagogical approaches. In this context, the design thinking (DT) methodology was proposed to tackle the problem. Originating in the development of psychological studies on creativity in the 1950s within the educational context, DT is known to foster creative thinking, help develop empathy, promote action-oriented actions, improve meta-cognitive awareness, contribute to problem-solving skills, and enhance students’ imagination. The last point supports the students’ development of critical thinking, social inclusion, teamwork skills, and academic performance. Thus, this paper introduces a methodological framework combining DT with ER classes. First, to approach the problem, the teachers’ survey data were collected and analysed to reveal the respondents’ level of integration of the DT methodology into current school curricula. Then, the work focused on the application of this framework in a learning experience by addressing the weakest points established and their elaboration through the combined ER and DT classes in the context of secondary schools.

Effectiveness of ENGAGE in reducing difficulties in everyday executive functions among Finnish preschoolers: a randomized controlled trial

ABSTRACT Effective interventions applicable for young preschool-age children are needed to reduce the risk of widespread and sustained adversities that are linked to early executive function (EF) difficulties. This randomized controlled trial (RCT) examined the effectiveness of the play-based ENGAGE intervention in improving behavioral outcomes related to EFs among Finnish preschool-age children with hyperactivity and/or inattention problems. 95 children between 4 and 5 years of age and their parents were randomly assigned to the ENGAGE intervention or a waitlist control group. Parents and early childhood education (ECE) teachers rated the children’s EF difficulties and problem behaviors at pre-intervention, post-intervention, and 5-month follow-up. Repeated measures linear mixed modeling was used to examine the effect of ENGAGE on child outcomes. Those receiving ENGAGE exhibited significantly greater decreases in parent-rated attentional problems, hyperactivity/impulsivity, and acting out behaviors than the control group did, with mostly moderate effect sizes. No consistent improvements in the teacher ratings of children’s EF related difficulties were found in either group. Low dropout (8%) from the intervention and high acceptability ratings indicated that ENGAGE is a palatable intervention for parents. The present study showed that findings from an earlier RCT on ENGAGE conducted in New Zealand could be generalized to a different cultural setting, as the intervention effectively reduced young Finnish children's EF difficulties in the home context. Extending ENGAGE and other play-based interventions into different everyday contexts of children, such as ECE, could further enhance the beneficial effects on children's EFs and behavior.

The Design of An LDO Regulator

In today’s modern systems on chip (SOCs), a crucial power management circuit is the low-dropout (LDO) regulator. Of course, the need for supply voltage regulation, goes back many years in the past since the circuits have been designed. Today, LDO based voltage regulators are frequently used in a number of mixed-signal systems to produce local supply voltages that feed different building blocks. LDOs try to isolate the noise of the circuit and noise from the global supply and try to reduce their effect on device performance. For the state of desired achievement, each LDO’s architecture is circuited to the specific cell it feeds. An LDO designed to feed a flash analog-to-digital converter, for instance, differs greatly from one designed to input a VCO. In this paper, we direct an LDO for a VCO of 5-GHz LC and point the particulars of 1.2 V as input voltage, produces 1V as output voltage, 5 mA of maximum output current, power supply rejection greater than 40 dB up to 10 MHz and noise voltage present at output that is less than 25nV/√Hz at 1 MHz.

Design of LDO circuit based on curvature compensation reference closed-loop stability

In this paper, a low dropout (LDO) circuit based on a curvature compensation benchmark and closed-loop stability is designed. This circuit compensates for the higher order term of VBE in a BJT through the subthreshold characteristic of MOSFET and achieves the effect of curvature compensation. The bandgap reference circuit provides a stable input voltage for the LDO circuit, while the source follower and adaptive bias circuit improve the response speed and closed-loop stability of the LDO circuit. The temperature drift coefficient of the bandgap circuit is 8.11 ppm/°C, the input voltage is 3–5 V, the output voltage is 2.8 V, and the linear adjustment rate is 0.22%.

A Single-Inductor–Triple-Output Buck DC-DC Converter With Electromagnetic Gated Low Dropouts for Higher Resistance to Electromagnetic and Power Side-Channel Attacks With 3B Minimum Traces to Disclosure Improvement in Internet of Things Applications

The security protection of IoT urges the design of low electromagnetic interference (EMI) and small power signature in power chips. To achieve high security, small chip area, and high efficiency, this paper proposes a single-inductor triple-output (SITO) buck DC-DC converter with Electromagnetic (EM) gated Low Dropouts (LDO) to reduce the EM leaked signature. Experimental results shows that the peak value of electromagnetic interference noise can be reduced from 88.44dBlV to 54.92dBlV, complying with EN 55032 Class B specifications. In addition, it can achieve 3 billion (B) minimum traces to disclosure (MTD) under power side-channel attack, which is at least three times improvement compared to prior-arts.

The role of learning in school persistence and dropout: A longitudinal mixed methods study in four countries

Using longitudinal quantitative and qualitative data we examine the role that learning plays in school persistence and dropout in Ethiopia, India, Peru, and Vietnam. Regression analysis shows a strong, significant association, with one standard deviation higher test scores associated with 50% lower odds of dropping out between the ages of 8 and 12, and a similar association between ages 12 and 15. Qualitative analysis indicates a direct relationship between low learning and dropout, with children and parents choosing to discontinue school when they realize little is being learned. Qualitative findings also show that low learning interacts with and exacerbates proximate causes of dropout, including early marriage and leaving school to work, as families decide which options will best provide for children in the long run. These findings suggest that low learning may play a larger role in dropout decisions than has been previously recognized, and that improving learning may also improve schooling attainment and completion.

The effectiveness of a home-based parent management training for preschoolers with oppositional behaviors in Israel: A randomized controlled trial

ObjectiveParent management training (PMT) is a well-established approach for treating young children's disruptive behavior. This randomized controlled trial (RCT) examined the effectiveness of Positive Parenting for Oppositional Preschoolers (PPOP), an Israeli-developed PMT intervention for treating young children's opposition and accompanying disruptive behaviors. MethodEighty-five Israeli parental couples (170 individuals: 85 fathers, and 85 mothers) with a 3–6-year-old child exhibiting non-clinical disruptive behavior were randomly assigned to either an 8-session PPOP (N = 42) or a waitlist control group (N = 43). Parents completed measures of child disruptive behavior, parenting stress, and parental self-efficacy before and after the intervention and at a 3-month follow-up. ResultsThe intervention effects (Cohen's d) were very large for children's disruptive behavior (d = 3.35), parenting stress (d = 1.78), and self-efficacy (d = 1.32). Improvements were only evident for the PPOP group, and all gains were maintained at follow-up. Participants in the waitlist control group did not report changes in their child's behavior, parenting stress, or parental self-efficacy. PPOP had a very low dropout rate (4.76%) and a very high attendance rate for mothers (100%) and fathers (98.7%). Both parents were highly satisfied with the parent training program. ConclusionsThis study provides evidence of the effectiveness of PPOP, a new home-based PMT intervention developed in Israel. In the short and long term, PPOP effectively treats young children's non-clinical disruptive behavior, reduces parenting stress, and increases parental self-efficacy.