A 30-MHz Voltage-Mode Buck Converter Using Delay-Line-Based PWM Control

Huang, Qiwei,Zhan, Chenchang,Burm, Jinwook IEEE 2018 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS PART 2 E Vol.65 No.11

<P>A 30-MHz voltage-mode buck converter using a delay-line-based pulse-width-modulation controller is proposed in this brief. Two voltage-to-delay cells are used to convert the voltage difference to delay-time difference. A charge pump is used to charge or discharge the loop filter, depending on whether the feedback voltage is larger or smaller than the reference voltage. A delay-line-based voltage-to-duty-cycle (V2D) controller is used to replace the classical ramp-comparator-based V2D controller to achieve wide duty cycle. A type-II compensator is implemented in this design with a capacitor and resistor in the loop filter. The prototype buck converter was fabricated using a 0.18- <TEX>${\mu }\text{m}$</TEX> CMOS process. It occupies an active area of 0.834 mm<SUP>2</SUP> including the testing PADs. The tunable duty cycle ranges from 11.9%–86.3%, corresponding to 0.4 V–2.8 V output voltage with 3.3 V input. With a step of 400 mA in the load current, the settling time is around 3 <TEX>${\mu }\text{s}$</TEX>. The peak efficiency is as high as 90.2% with 2.4 V output and the maximum load current is 800 mA.</P>

An Energy-Efficient Frequency-Domain CMOS Temperature Sensor With Switched Vernier Time-to-Digital Conversion

Huang, Qiwei,Joo, Hyobin,Kim, Jinwoo,Zhan, Chenchang,Burm, Jinwook IEEE 2017 IEEE SENSORS JOURNAL Vol.17 No.10

<P>This paper presents a CMOS smart temperature sensor using a switched Vernier time-to-digital converter to achieve an energy-efficient temperature sensing. The proposed temperature sensor employs two switched ring oscillators (SROs), of which the oscillation frequencies are slightly different from each other and varying linearly with temperature due to the deployment of a proportional-to-absolute-temperature current generator. The frequencies of the two SROs are measured by counting the rising edges with two counters, and hence, the frequency difference corresponding to temperature can be readily monitored with the digital numbers. A control strategy that switches OFF the ring oscillators after each sampling is developed, such that significant power saving is achieved. The proposed temperature sensor shows a measured resolution of 0.048 degrees C from -20 degrees C to 120 degrees C with 100-ms conversation time. With 1-kHz sampling rate, the power consumption is as small as 93.6 mu W, resulting in 93.6 nJ per sampling. The chip area is 0.118 mm(2) in a standard 0.18-mu m CMOS process.</P>

Structural Relationship between Motivation, Involvement, Satisfaction and Loyalty of University Basketball Participants in China

( Qiwei Yang ),( Xin Qi ),( Shihao Huang ),( Chuan Yi ),( Yinggang Chen ) 아시아스포츠융합과학회 2021 Asia Pacific Journal of Applied Sport Sciences Vol.2 No.2

PURPOSE The main purpose of this study is to test the structural relationship between motivation, involvement, satisfaction and loyalty of university basketball participants in China. METHOD The study took the participants of basketball clubs from five universities in Hunan Province as the subject. 846 questionnaires were collected and 800 were used in this study. SPSS24 and AMOS were used for this research. RESULT The results show that the motivation of basketball club’s participants has a significant positive impact on involvement, satisfaction and loyalty; Involvement has a significant positive effect on satisfaction and loyalty; Satisfaction has significant positive influence to loyalty. Finally, involvement and satisfaction can play a partial mediating role between motivation and loyalty. CONCLUSION This study verifies the structural relationship between motivation, involvement, satisfaction and loyalty of Chinese college basketball club participants. Motivation is the most important factor affecting participants’ loyalty, while involvement has the least impact on participants’ satisfaction and loyalty. Consequently, the PE management staff in university should attach more importance the motivation of participants in order to attract more students to participate in basketball activity and maintain their interests.

High Frame Rate VGA CMOS Image Sensor using Three Step Single Slope Column-Parallel ADCs

Junan Lee,Qiwei Huang,Kiwoon Kim,Kyunghoon Kim,Jinwook Burm 대한전자공학회 2015 Journal of semiconductor technology and science Vol.15 No.1

This paper proposes column-parallel three step Single Slope Analog-to-Digital Converter (SSADC) for high frame rate VGA CMOS Image Sensors (CISs). The proposed three step SS-ADC improves the sampling rate while maintaining the architecture of the conventional SS-ADC for high frame rate CIS. The sampling rate of the three-step ADC is increased by a factor of 39 compared with the conventional SSADC. The proposed three-step SS-ADC has a 12-bit resolution and 200 kS/s at 25 ㎒ clock frequency. The VGA CIS using three step SS-ADC has the maximum frame rate of 200 frames/s. The total power consumption is 76 ㎽ with 3.3 V supply voltage without ramp generator buffer. A prototype chip was fabricated in a 0.13 μm CMOS process.

High Frame Rate VGA CMOS Image Sensor using Three Step Single Slope Column-Parallel ADCs

Lee, Junan,Huang, Qiwei,Kim, Kiwoon,Kim, Kyunghoon,Burm, Jinwook The Institute of Electronics and Information Engin 2015 Journal of semiconductor technology and science Vol.15 No.1

This paper proposes column-parallel three step Single Slope Analog-to-Digital Converter (SS-ADC) for high frame rate VGA CMOS Image Sensors (CISs). The proposed three step SS-ADC improves the sampling rate while maintaining the architecture of the conventional SS-ADC for high frame rate CIS. The sampling rate of the three-step ADC is increased by a factor of 39 compared with the conventional SS-ADC. The proposed three-step SS-ADC has a 12-bit resolution and 200 kS/s at 25 MHz clock frequency. The VGA CIS using three step SS-ADC has the maximum frame rate of 200 frames/s. The total power consumption is 76 mW with 3.3 V supply voltage without ramp generator buffer. A prototype chip was fabricated in a $0.13{\mu}m$ CMOS process.

Determination and correlation of the solubility of L-arabinose and D-galactose in binary solvent mixtures from 278.15 to 333.15K

Min Li,Minhui Huang,Zhiguo Zhang,Qiwei Yang,Yiwen Yang,Zongbi Bao,Qilong Ren 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.10

L-arabinose and D-galactose could be released during the hydrolysis process of Arabic gum. The development of a crystallization process of L-arabinose is highly dependent on the knowledge of the solubility of both saccharides. In this work, the solubility of L-arabinose and D-galactose in binary mixtures of methanol-water or ethanolwater (mole fraction of water 0.5816) was determined at temperatures between 278.15 and 333.15K by a static equilibrium method. The experimental data correlated well with the modified Apelblat equation, the simplified polynomial empirical equation, NRTL model and UNIQUAC model. Additionally, the thermodynamic properties including the dissolution enthalpy and entropy were obtained from the experimental data. Within the studied temperature range, the dissolution is endothermic and the dissolution process is non-spontaneous.

Multilevel Pedicle Subtraction Osteotomy for Correction of Thoracolumbar Kyphosis in Ankylosing Spondylitis: Clinical Effect and Biomechanical Evaluation

Xin Lv,Yelidana Nuertai,Qiwei Wang,Di Zhang,Xumin Hu,Jiabao Liu,Ziliang Zeng,Renyuan Huang,Zhihao Huang,Qiancheng Zhao,Wenpeng Li,Zhilei Zhang,Liangbin Gao 대한척추신경외과학회 2024 Neurospine Vol.21 No.1

Objective: To compare the clinical outcomes and biomechanical characteristics of 1-, 2-, and 3-level pedicle subtraction osteotomy (PSO), and establish selection criteria based on preoperative radiographic parameters. Methods: Patients undergone PSO to treat ankylosing spondylitis from February 2009 to May 2019 in Sun Yat-sen Memorial Hospital of Sun Yat-sen University were enrolled. According to the quantity of osteotomy performed, the participants were divided into group A (1-level PSO, n = 24), group B (2-level PSO, n = 19), and group C (3-level PSO, n = 11). Clinical outcomes were assessed before surgery and at the final follow-up. Comparisons of the radiographic parameters and quality-of-life indicators were performed among and within these groups, and the selection criteria were established by regression. Finite element analysis was conducted to compare the biomechanical characteristics of the spine treated with different quantity of osteotomies under different working conditions. Results: Three-level PSO improved the sagittal parameters more significantly, but resulted in longer operative time and greater blood loss (p < 0.05). Greater stress was found in the proximal screws and proximal junction area of the vertebra in the model simulating 1-level PSO. Larger stress of screws and vertebra was observed at the distal end in the model simulating 3-level PSO. Conclusion: Multilevel PSO works better for larger deformity correction than single-level PSO by allowing greater sagittal parameter correction and obtaining a better distribution of stress in the hardware construct, although with longer operation time and greater blood loss. Three-level osteotomy is recommended for the patients with preoperative of global kyphosis > 85.95°, T1 pelvic angle > 62.3°, sagittal vertical alignment > 299.55 mm, and pelvic tilt+ chin-brow vertical angle > 109.6°.

The characteristics of voltage-gated sodium channel and the association with lambda cyhalothrin resistance in Spodoptera exigua

Xiangrui Tian,Jidong Liu,Zimu Guo,Bo Hu,Mburu David Kibe,Shiyu Wang,Jianya Su,Qiwei Huang 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.3

Spodoptera exigua has developed very high resistance to pyrethroid insecticides; however, the mode-of-action target of pyrethroids has not been studied, and the mechanism for target resistance remains elusive in this insect. In this study the resistance level of a field collected population from Huizhou, China was assayed with leaf-dip method and further selected in laboratory. The transcripts of voltage-gated sodium channel gene from S. exigua were cloned and analyzed for the structural characteristics, the relative expression levels of transcripts were measured by quantitative RT-PCR. Finally, detection of the point mutations was performed. The bioassay indicated that Huizhou population had developed 309.5-fold resistance to lambda-cyhalothrin, and the selection in laboratory led to the resistant strain (HZ14-sel) with increased resistance of 423-fold. Nine transcripts of sodium channel with 4517–6149 bp nucleotides were identified from S. exigua, among which only one transcript (SeNav4) encode the functional protein with complete domains, and other eight transcripts were observed to lost some transmembrane segments. The L834F mutation in IIS6 corresponding for the typical kdr mutation “L1014F”, was detected in 50% individuals of HZ14-sel strain. These results suggested that lambda-cyhalothrin resistance is associated with point mutations and expression level changes of sodium channel transcripts in HZ14-sel strain.