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Yutian Chen

Bio: Yutian Chen is an academic researcher from Southern University of Science and Technology. The author has contributed to research in topics: Low-dropout regulator & Power supply rejection ratio. The author has an hindex of 1, co-authored 2 publications receiving 1 citations.

Papers
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Proceedings ArticleDOI
22 May 2021
TL;DR: A Power-area-efficient output-capacitorless low- dropout (OCL-LDO) regulator with fast transient response is presented in this paper and shows a good of flgure-of-merit (FOM).
Abstract: A Power-area-efficient output-capacitorless low- dropout (OCL-LDO) regulator with fast transient response is presented in this paper. The proposed technique permits the regulator to achieve small undershoot (overshoot) when the load steps up (down) and consumes little extra power. The proposed LDO regulator has been implemented and fabricated in a 0.18- μm CMOS process. It occupies an active area of0.0071mm2. The simulated results have shown that the proposed circuit consumes a quiescent current of 0.7 μΑ at no load, regulating the output at 0.7 V from a voltage supply of 0.9 V. The simulated transient output voltage is 47 mV when load current is stepped from 1 mA to 20 mA in 400 ns with C l =3D10 pF. Meanwhile, this circuit shows a good of flgure-of-merit (FOM).

9 citations

Journal ArticleDOI
TL;DR: This brief presents a picowatt CMOS voltage reference with ultra-low supply and wide temperature range, Biased by PMOS leakage current,Ultra-low voltage and ultra- low power consumption are achieved.
Abstract: This brief presents a picowatt CMOS voltage reference with ultra-low supply and wide temperature range. Biased by PMOS leakage current, ultra-low voltage and ultra-low power consumption are achieved. The temperature range is enlarged by using the increased bulk diode leakage current modulation (BDLCM) effect at high temperature. The proposed design is implemented in a standard 0.18- $\mu \text{m}$ CMOS process. The measurement results show that, the proposed circuit can provide an average voltage reference of 118.1 mV with a standard deviation of 1.3 mV. The minimum supply voltage is 250 mV and the line sensitivity (LS) is 0.3 %/V. The average temperature coefficient (TC) is 73.5 ppm/°C with a standard deviation of 11.7 ppm/°C within a temperature range from −40 °C to 140 °C. The power supply ripple rejection (PSRR) at 100 Hz is −65 dB. The power consumption at room temperature is 113 pW and the active area is 0.0009 mm2.

8 citations

Journal ArticleDOI
TL;DR: Phylogenetic analysis suggests a relatively recent evolutionary branching of putative twitch radical SAM epimerases bearing homologous cysteine residues to generate the SpeY clade of enzymes.
Abstract: Spectinomycin is a dioxane-bridged, tricyclic aminoglycoside produced by Streptomyces spectabilis ATCC 27741. While the spe biosynthetic gene cluster for spectinomycin has been reported, the chemistry underlying construction of the dioxane ring is unknown. The twitch radical SAM enzyme SpeY from the spe cluster is shown here to catalyze dehydrogenation of the C2' alcohol of (2'R,3'S)-tetrahydrospectinomycin to yield (3'S)-dihydrospectinomycin as a likely biosynthetic intermediate. This reaction is radical-mediated and initiated via H atom abstraction from C2' of the substrate by the 5'-deoxyadenosyl radical equivalent generated upon reductive cleavage of SAM. Crystallographic analysis of the ternary Michaelis complex places serine-183 adjacent to C2' of the bound substrate opposite C5' of SAM. Mutation of this residue to cysteine converts SpeY to the corresponding C2' epimerase mirroring the opposite phenomenon observed in the homologous twitch radical SAM epimerase HygY from the hygromycin B biosynthetic pathway. Phylogenetic analysis suggests a relatively recent evolutionary branching of putative twitch radical SAM epimerases bearing homologous cysteine residues to generate the SpeY clade of enzymes.

3 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article , a tiny-size ultra-low voltage CMOS voltage reference operating at quiescent picoamp scale has been proposed to fit the high standards of modern wireless microsystems.

2 citations

Journal ArticleDOI
01 Nov 2022
TL;DR: In this article , an NMOS-only voltage reference with small process variations for ultra-low-power applications is presented, where an optimum body selection (OBS) is proposed to reduce the impact of the process variations.
Abstract: This brief presents an NMOS-only voltage reference with small process variations for ultra-low-power applications. All MOSFETs work in the subthreshold region and are biased by the leakage current of the NMOS transistor manufactured in Deep-N-Well (DNW). By fitting the variations of threshold voltage ( $\text{V}_{\mathrm{ TH}}$ ) from slow/fast corners to typical corners linearly, an optimum body selection (OBS) is proposed to reduce the impact of the process variations from $\text{V}_{\mathrm{ TH}}$ or $\Delta \text{V}_{\mathrm{ TH}}$ with the aid of the body effect. The proposed design was fabricated in a 0.18- $\mu \text{m}$ CMOS process, together with a baseline design without using the OBS. Based on the 25-chip measurement results, the output voltage variation of the proposed design is $0.0035 \sigma /\mu $ , which is 61% smaller than that of the baseline design. Besides, for the proposed design with the OBS, the power consumption is 23pW (27°C), while the die area is 0.003mm2. The temperature coefficient is 52ppm/°C in a temperature range from 0°C to 85°C without trimming. The line sensitivity is 0.03%/V, and the power supply rejection ratio is 47dB at 100Hz.

2 citations

Journal ArticleDOI
TL;DR: In vitro characterization of Her4 and Her5 demonstrates their involvement in an initial, two-stage C-C coupling reaction that results in net C5'-glycosylation of ADP/ATP by UDP/TDP-glucuronic acid, and an overall herbicidin biosynthetic pathway is proposed.
Abstract: Herbicidins are adenosine-derived nucleoside antibiotics with an unusual tricyclic core structure. Deletion of the genes responsible for formation of the tricyclic skeleton in Streptomyces sp. L-9-10 reveals the in vivo importance of Her4, Her5, and Her6 in the early stages of herbicidin biosynthesis. In vitro characterization of Her4 and Her5 demonstrates their involvement in an initial, two-stage C-C coupling reaction that results in net C5'-glycosylation of ADP/ATP by UDP/TDP-glucuronic acid. Biochemical analyses and intermediate trapping experiments imply a noncanonical mechanism of C-glycosylation reminiscent of NAD-dependent S-adenosylhomocysteine (SAH)-hydrolase catalysis. Structural characterization of the isolated metabolites suggests possible reactions catalyzed by Her6 and Her7. An overall herbicidin biosynthetic pathway is proposed based on these observations.

1 citations