Browsing by Author "Du, Ming-Jhe"

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120% Harvesting Energy Improvement by Maximum Power Extracting Control for High Sustainability Magnetic Power Monitoring and Harvesting System
(2015-04-01)
Huang, Tzu-Chi
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Du, Ming-Jhe
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Kang, Yu-Chai
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Peng, Ruei-Hong
;
Chen, Ke-Horng
The magnetic energy harvesting (MEH) circuit and the power monitoring system are proposed in this paper to enlarge the system sustainability on wireless sensing or the monitoring system. The proposed MEH circuit harvests magnetic power on power wires through a power sensing current transformer (CT) and charges power monitoring system. The MEH circuit includes the direct ac-dc rectifier and the maximum power extracting (MPE) control circuit. The direct ac-dc rectifier can directly rectify ac input to the dc output current. The proposed MPE control fits the characteristic of magnetic energy source compared to the conventional resistor emulation maximum power point tracking method. Owing to continuous tracking the maximum power of the CT, 120% harvesting power improvement can be achieved under the same CT\'s sensing current. Peak efficiency of 82% can be achieved under the sensing current of 8 A. The test chip is fabricated in 0.25 mu m CMOS process with an active area of 0.98 mm(2).
A 80V Output Voltage Boost Converter with Low Voltage Ripple for Avalanche Photodiode(APD)
(2011)
Yang, Yao-Yi
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Hsieh, Chun-Yu
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Huang, Tzu-Chi
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Lee, Yu-Huei
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Wang, Shih-Wei
The Avalanche Photodiodes (APDs) are widely used in a variety of optical application requiring high sensitivity, such as long-distance optical communication and optical distance measurement, because the APDs can detect the low level light. APDs accompanied with the Transimpedance Amplifier (TIA) are utilized on the receiver side in the communication system. The trend of integrating the active optical components faces the challenge of integrating different voltage levels. In general, the operation voltage of TIA is usually 1.8 V or 3.3 V. However, the APD requires a high reverse-biasing voltage of 40 V - 80 V. Therefore, a high conversation-ratio boost converter must be included to provide the high voltage to bias the APD. Besides, output voltage ripple must be minimized to decrease the influence on communication signals. Experimental results show the 80 V output voltage boosted from the input voltage of 2.5 V. The output voltage ripple is 2 mV under the condition of 1 mA load current.
A Direct AC-DC and DC-DC Cross-Source Energy Harvesting Circuit with Analog Iterating-Based MPPT Technique with 72.5% Conversion Efficiency and 94.6% Tracking Efficiency
(2016-08)
Chen, Shin-Hao
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Huang, Tzu-Chi
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Ng, Shao Siang
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Lin, Kuei-Liang
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Du, Ming-Jhe
The proposed cross-source energy (CSE) harvesting system accepts universal energy sources, including the ac and dc sources. The buck-boost conversion of CSE automatically converts ac or dc input into dc output without being limited by the type of universal energy source. The CSE technique simultaneously supplies the regulated output for the system loading and the battery charging output. A test chip fabricated in the VIS Bipolar, CMOS, and DMOS (BCD) process can optimally derive harvest energy with 72.5% power efficiency when one solar input source is used. A backup converter is designed to complement the CSE technique to guarantee the regulation of output voltage. The proposed analog iterating-based (AIB) maximum power point tracking (MPPT) technique achieves 94.6% tracking efficiency without complex data calculation and storage, which are better results compared with those of previous research.
A Photovoltaic System with Analog Maximum Power Point Tracking and Grid-Synchronous Control
(2012)
Huang, Tzu-Chi
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Lee, Yu-Huei
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Du, Ming-Jhe
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Hsieh, Chun-Yu
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Yang, Chih-Yu
A low cost maximum power point tracking (MPPT) technique is proposed in this paper for high power efficiency in photovoltaic systems to track the maximum power point (MPP). Compared to the various studies of the MPPT topologies, the proposed implementation is achieved by monitoring the power slope conditions of solar panels. The post grid-connected DC-AC inverter helps feedback the transformative power for providing AC power. Experiment results demonstrate the rapid tracking operation of MPP and a high tracking effectiveness of 97.3%.
Current-Mode Synthetic Control (CSC) Technique for High Efficiency DC-DC Boost Converters Over a Wide Load Range
(2011)
Su, Yi-Ping
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Chen, Yi-Chun
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Huang, Han-Hsiang
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Lee, Yu-Huei
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Yang, Yao-Yi
The proposed current-mode synthetic control (CSC) technique in the design of boost converters can improve the transient response time and maintain high conversion efficiency over a wide load range. The CSC technique has high accuracy similar to the current-mode control and doesn't need the slope compensation for simplicity. Besides, the transient response is also improved due to the current-mode hysteresis control. The load-dependent switching frequency at light loads results in high power conversion efficiency. Experimental results show that the output voltage ripple can be kept smaller than 50mV over a wide load current range from 0mA to 400mA with power conversion efficiency higher than 90% at load current of 10mA.
Non-invasion Power Monitoring with 120% Harvesting Energy Improvement by Maximum Power Extracting Control for High Sustainability Power Meter System
(2012)
Huang, Tzu-Chi
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Du, Ming-Jhe
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Yang, Yao-Yi
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Lee, Yu-Huei
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Kang, Yu-Chai
Magnetic energy harvesting (MEH) circuit for system sustainability and power monitoring system with a novel dual-wire current transformer (DWCT) are proposed in this paper. MEH circuit simultaneously senses and harvests the magnetic energy. DWCT has the benefits of non-invasion measurement (NIM) and is easy to use. The designed direct AC-DC rectifier with maximum power extracting (MPE) control fits the characteristic of magnetic energy source. Thus, 120% harvesting power improvement can be achieved under the same sensing current.
Projection moire profilometry with high-dynamic range image
(2012-02-01)
Chou, Sen-Yih
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Cho, Chia-Hung
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Du, Ming-Jhe
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Chi, Sien
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光電工程學系
As a type of optical measuring apparatus, the charge-coupled diode (CCD) camera provides the capability of increasing the speed of measurement by inspecting an area with only one shot. However, the CCD camera's high-variation range of reflectivity presents an exceptional challenge for the optical measurement established on the surface. We present a method that could enable one to acquire an image with a high-dynamic range in one shot without any reduction in spatial resolution. Because of the sufficient signal-to-noise ratio, the method presented could perform the robustness of the phase-retrieving algorithm, and the surface topography could be measured more accurately. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.2.021112]
Reduction of Equivalent Series Inductor Effect in Constant On-Time Control DC-DC Converter without ESR Compensation
(2011)
Lee, Yu-Huei
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Lai, Wang-Wei
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Pai, Wan-Yu
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Chen, Ke-Horng
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Du, Ming-Jhe
The proposed constant on-time control DC-DC converter removes the need of conventional equivalent series resistor (ESR) compensation and simultaneously aims to eliminate equivalent series inductor (ESL) effect of the output capacitor. Since the on-time period is set simply by input and output voltages, the switching frequency in continuous conduction mode (CCM) operation is relatively constant over a wide input voltage range. In addition, fast transient response and small transient dip voltage can be achieved. Simulation results show that the output ripple and the recovery time keep smaller than 5 mV and 10 mu s, respectively, when load current step is 500 mA and ESR is smaller than 5 m Omega.
Reduction of Equivalent Series Inductor Effect in Delay-Ripple Reshaped Constant On-Time Control for Buck Converter With Multilayer Ceramic Capacitors
(2013-05-01)
Chen, Wei-Chung
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Wang, Ching-Sung
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Su, Yi-Ping
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Lee, Yu-Huei
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Lin, Chia-Ching
The stability of conventional constant on-time control buck converter is constrained by the time constant, which is the product of the output capacitor and its equivalent series resistance (ESR). Specialty polymer capacitor which is mostly used as output capacitor for such a consideration although it limits the performance of converter. On the other hand, the multilayer ceramic capacitors are widely used in commercial power management ICs due to the advantages of low cost and ESR. However, the stability often confronts with the subharmonic problem caused by small time constant. A differential-zero compensator with the noise margin enhancement (DZC-NME) technique in constant on-time control buck dc-dc converter with output ceramic capacitor is proposed in this paper. Thus, the proposed DZC-NME technique not only eliminates the limit of large time constant but also tolerates the existence of equivalent series inductor (ESL) effect. Experiment results demonstrate small output ripple of 10 mV and high efficiency of 91% when ESR is smaller than 1 m Omega and large interference from ESL effect is 40 mV.
Robust Switch-mode Charger with Bootstrap Detector (BSD) and Soft-start Embedded in Type III Compensation (SSEC) Technique
(2012)
Peng, Ruei-Hong
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Su, Yi-Ping
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Tsai, Tsu-Wei
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Chen, Ya-Ping
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Chen, Ke-Horng
Bootstrap detector (BSD) and soft-start embedded in Type III compensation (SSEC) are implemented in the switch-mode charger to achieve high efficiency and ensure robustness charging process. The proposed BSD monitors the bootstrap voltage to avoid low efficiency and serious burning problem in both synchronous and non-synchronous charging modes. On the other hand, the SSEC avoids inrush current in start-up procedure of charger system without any external components and auxiliary circuits to greatly minimize the chip and footprint areas. The proposed robust switch-mode charger with the BSD and the SSEC technique was simulated in 0.25 mu m CMOS process. The fast charge current in constant current stage varies from 600 mA to 10 A with a 1.6 MHz operating switching frequency.
Single Controller Current Balance (SCCB) Technique for Voltage-Mode Multi-Phase Buck Converter
(2011)
Huang, Yu-Ping
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Su, Yi-Ping
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Lee, Yu-Huei
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Chu, Kuan-Yu
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Shih, Chun-Jen
a single controller current balance (SCCB) technique is proposed to achieve the time-multiplexing current balance in voltage-mode multi-phase DC-DC buck converter with only one modulation controller. Thus, the N-1 controllers can be removed when the SCCB technique is implemented in the monolithic N-phase DC-DC buck converters for largely decreasing the silicon area and power consumption. In addition, the time-multiplexing current balance scheme can further enhance the current sharing accuracy since the mismatches between different controllers does not exist. Simulated results show that the current difference between each phase can be decreased by over 80 % at both heavy load and light load conditions.