A High Efficiency and Low Ripple Cross-Coupled Charge Pump Circuit

A fully integrated cross-coupled charge pump circuit with four-clock signals and a new method of body bias have been proposed. The new clock scheme eliminates all of the reversion power loss and reduces the ripple voltage. In addition, the largest voltage differences between the terminals of all transistors do not exceed the supply voltage. We have also solved the gate-oxide overstress problem in the conventional charge pump circuits and enhanced the reliability. The proposed charge pump circuit has been simulated using Spectre and in the TSMC 0.18um CMOS process. The simulation results show that the maximum voltage conversion efficiency of the new 3-stage cross-coupled circuit with an input voltage of 1.5V is 99.8%. Moreover, the output ripple voltage has been significantly reduced.Peer reviewe

A robust high-efficiency cross-coupled charge pump circuit without blocking transistors

This document is the Accepted Manuscript version of the following article: Minglin Ma, Xinglong Cai, Yichuang Sun, and Nike George, ‘A robust high-efficiency cross-coupled charge pump circuit without blocking transistors’, Analog Integrated Circuits and Signal Processing, Vol. 95 (3): 395-401, June 2018. Under embargo until 16 March 2019. The final publication is available at Springer via: https://doi.org/10.1007/s10470-018-1149-xA fully integrated cross-coupled charge pump circuit with a new clock scheme has been presented in this paper. The new clock scheme ensures that all NMOS pre-charge transistors are turned off when the voltages of main clock signals are high. Notably, all PMOS transfer transistors will be turned off when the voltages of the main clock signals are low. As a result, the charge pump eliminates all of the reversion power loss and reduces the ripple voltage. The proposed charge pump has a better performance even in scenarios where the main clock signals are mismatched. The proposed charge pump circuit was simulated using spectre in the TSMC 0.18 µm CMOS process. The simulation results show that the proposed charge pump circuit has a high voltage conversion efficiency and low ripple voltage.Peer reviewe

High Efficiency Cross-Coupled Charge Pump Circuit with Four-Clock Signals

© Allerton Press, Inc. 2018A fully integrated cross-coupled charge pump circuit for boosting dc-to-dc converter applications with four-clock signals has been proposed. With the new clock scheme, this charge pump eliminates all of the reversion power loss and reduces the ripple voltage. In addition, the largest voltage differences between the terminals of all transistors do not exceed the power supply voltage for solving the gate-oxide overstress problem in the conventional charge pump circuits and enhancing the reliability. This proposed charge pump circuit does not require any extra level shifter; therefore, the power efficiency is increased. The proposed charge pump circuit has been simulated using Spectre in the TSMC 0.18 μm CMOS process. The simulation results show that the maximum voltage conversion efficiency of the new 3-stage cross-coupled circuit with an input voltage of 1.5Vis 99.8%. According to the comparison results of the conventional pump and the enhanced charge pump proposed, the output ripple voltage has been significantly reduced.Peer reviewe

Potential of Core-Collapse Supernova Neutrino Detection at JUNO

JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

Detection of the Diffuse Supernova Neutrino Background with JUNO

As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30$M_{\odot}$ for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

Study on the relationship between intracellular metabolites and astaxanthin accumulation during Phaffia rhodozyma fermentation

Background: To study the relationship between intracellular anabolism and astaxanthin production, the influence of intracellular protein and fatty acids on astaxanthin production by four mutant Phaffia rhodozyma strains and their variations was investigated in this research. Results: First, the content of astaxanthin in cells showed a reverse fluctuation in contrast to that of protein during the whole fermentation process. Moreover, compared with the three other strains, the astaxanthin-overproducing mutant strain of the yeast P. rhodozyma, called JMU-MVP14, had the highest specific productivity of astaxanthin as 6.8 mg/g, whereas its intracellular protein and fatty acid contents were the lowest. In addition, as a kind of sugar metabolic product, ethanol was only produced by P. rhodozyma JMU-VDL668 and JMU-7B12 during fermentation. Conclusions: The results indicated that the accumulation of ethanol, intracellular protein, and fatty acids had competition effects on astaxanthin synthesis. This condition may explain why the P. rhodozyma strains JMU-VDL668 and JMU-7B12 achieved relatively lower astaxanthin production (1.7 and 1.2 mg/L) than the other two strains JMU-MVP14 and JMU-17W (20.4 and 3.9 mg/L)

Refined Composite Multiscale Fluctuation Dispersion Entropy and Supervised Manifold Mapping for Planetary Gearbox Fault Diagnosis

A novel fault diagnosis scheme was developed to address the difficulty of feature extraction for planetary gearboxes using refined composite multiscale fluctuation dispersion entropy (RCMFDE) and supervised manifold mapping. The RCMFDE was first utilized in this scheme to fully mine fault features from planetary gearbox signals under multiple scales. Subsequently, as a supervised manifold mapping method, supervised isometric mapping (S-Iso) was applied to decrease the dimensions of the original features and remove redundant information. Lastly, the marine predator algorithm-based support vector machine (MPA-SVM) classifier was employed to achieve intelligent fault diagnosis of planetary gearboxes. The suggested RCMFDE combines the composite coarse-grained construction and refined computing technology, overcoming unstable and invalid entropy in the traditional multiscale fluctuation dispersion entropy. Simulation experiments and fault diagnosis experiments from a real planetary gearbox drive system show that the complexity measure capability and feature extraction effectiveness of the proposed RCMFDE outperform the multiscale fluctuation dispersion entropy (MFDE) and multi-scale permutation entropy (MPE). The S-Iso’s visualization results and dimensionality reduction performance are better than principal components analysis (PCA), linear discriminant analysis (LDA), and isometric mapping (Isomap). Moreover, the suggested fault diagnosis scheme has an accuracy rate of 100% in identifying bearing and gear defects in planetary gearboxes