Browsing by Author "Lee, Yu"

Now showing 1 - 8 of 8

A 8 Phases 192 MHz Crystal-Less Clock Generator with PVT Calibration
(2017-01)
Lu, Ting-Chou
;
Ker, Ming-Dou
;
Zan, Hsiao-Wen
;
Liu, Jen-Chieh
;
Lee, Yu
A multi-phase crystal-less clock generator (MPCLCG) with a process-voltage-temperature (PVT) calibration circuit is proposed. It operates at 192 MHz with 8 phases outputs, and is implemented as a 0.18pm CMOS process for digital power management systems. A temperature calibrated circuit is proposed to align operational frequency under process and supply voltage variations. It occupies an area of 65 mu m x 75 mu m and consumes 1.1 mW with the power supply of 1.8 V. Temperature coefficient (TC) is 69.5 ppm/degrees C from 0 to 100 degrees C, and 2-point calibration is applied to calibrate PVT variation. The measured period jitter is a 4.58-ps RMS jitter and a 34.55-ps peak-to-peak jitter (P2P jitter) at 192 MHz within 12.67k-hits. At 192 MHz, it shows a 1-MHz-offset phase noise of -102 dBc/Hz. Phase to phase errors and duty cycle errors are less than 5.5% and 4.3%, respectively.
A 8 Phases 192 MHz Crystal-Less Clock Generator with PVT Calibration
(2017-01)
Lu, Ting-Chou
;
Ker, Ming-Dou
;
Zan, Hsiao-Wen
;
Liu, Jen-Chieh
;
Lee, Yu
A multi-phase crystal-less clock generator (MPCLCG) with a process-voltage-temperature (PVT) calibration circuit is proposed. It operates at 192 MHz with 8 phases outputs, and is implemented as a 0.18pm CMOS process for digital power management systems. A temperature calibrated circuit is proposed to align operational frequency under process and supply voltage variations. It occupies an area of 65 mu m x 75 mu m and consumes 1.1 mW with the power supply of 1.8 V. Temperature coefficient (TC) is 69.5 ppm/degrees C from 0 to 100 degrees C, and 2-point calibration is applied to calibrate PVT variation. The measured period jitter is a 4.58-ps RMS jitter and a 34.55-ps peak-to-peak jitter (P2P jitter) at 192 MHz within 12.67k-hits. At 192 MHz, it shows a 1-MHz-offset phase noise of -102 dBc/Hz. Phase to phase errors and duty cycle errors are less than 5.5% and 4.3%, respectively.
A Sustainable Soil Energy Harvesting System With Wide-Range Power-Tracking Architecture
(2019-10-01)
Ou, I-Che
;
Yang, Jia-Ping
;
Liu, Chia-Hung
;
Huang, Kai-Jie
;
Tsai, Kun-Ju
For wide-range deployment of wireless sensing nodes in power- and size-constrained Internet of Things applications, self-sustaining wireless sensors without batteries are needed. The energy supply for these ubiquitous sensing devices should harness environmental energy sources to avoid frequent battery replacement and pollution. This paper presents a new soil energy harvesting system with a power management integrated circuit (IC) for wide-range maximum power point tracking (MPPT). The output power of a soil energy cell varies widely according to the soil moisture and soil contents. To extract the maximum amount of energy from the soil, high-efficiency power management with adaptive dc-dc conversion ratios and an MPPT mechanism is essential. The proposed system is implemented with a high-efficiency dc-dc converter IC in a 0.18-mu m CMOS process. The design achieves a peak tracking efficiency of 90.5% in the throughput power range from 56 mu W to 1 mW at an output voltage of 3 V and system efficiency exceeding 65% over an input resistance range of the soil energy source; the peak system efficiency is 73.9%. A demonstration was undertaken of the soil energy harvesting system lighting an LED array without any chemical batteries.
A Wide-Range Capacitive DC-DC Converter with 2D-MPPT for Soil/Solar Energy Extraction
(2018-01-01)
Ou, I-Che
;
Yang, Jia-Ping
;
Liu, Chia-Hung
;
Huang, Kai-Jie
;
Tsai, Kun-Ju
This paper presents a capacitive DC-DC converter with adaptive DC-DC conversion ratios and maximum power point tracking (MPPT) for soil and solar energy extraction. To overcome the varying input power ranges of the soil/solar energy sources, a two-dimension power tracking loop with time-based current slope detection was employed. The design was fabricated in a 0.18 mu m CMOS process, achieving >80% efficiency in a throughput power range of 360 mu W to 25mW in the soil mode and from 400 mu W to 10mW in the solar mode while the peak system efficiency is 89.5%.
Essential factors that affect bioelectricity generation byRhodopseudomonas palustrisstrainPS3in paddy soil microbial fuel cells
(1970-01-01)
Liu, Chia-Hung
;
Lee, Sook-Kuan
;
Ou, I-Che
;
Tsai, Kun-Ju
;
Lee, Yu
A plant-associated phototrophic bacterium,R. palustrisstrain PS3, was inoculated into a soil-based MFC to generate electricity. We evaluated the performance of this soil-based microbial fuel cell (MFC) and elucidated the essential factors that contributed to power generation. PS3 showed the potential to enhance power generation, especially when the apparatus was operated in a sealed chamber with illumination.We deduced that the improved power performance was due to the enhanced electron transport through the living electrode that was grown as a PS3 biofilm via photoheterotrophic metabolism. In addition, we suggested that the interplay between phototrophic fixation of ambient CO(2)and anaerobic oxidation of ferrous iron in soil was also involved in the increased power output. We implemented CMOS (complementary metal-oxide-semiconductor) technology with the soil-based MFC to harvest energy in a more efficient and stable manner. The above system is expected to provide a potentially low-cost and low-energy system with a high power conversion efficiency for practical applications in the future.
Integrated Biosensing Platform Based on a 1.74-mW-90-dBm Sensitivity Dual-Mode-Operation Receiver for IEEE 802.15.6 Human Body Communication Standard
(2015-06-01)
Tsou, Yu Lin
;
Gong, Cihun-Siyong Alex
;
Cheng, Nai Chen
;
Lee, Yu
;
Jou, Christina F.
Human body communication (HBC), a technique featuring low conduction loss and low interference by taking the advantages of the nature of body composition, has emerged as one of the most promising techniques toward next-generation wireless body area network (WBAN). The regulation of WBAN, IEEE 802.15.6, concerning the standard of physical layer has also been established in 2012. The intensity of electric field around body is affected by the transmission distance, quality of electrode-skin contact, and so on which results in wide variance in path loss. In addition, according to the measurement results, the equivalent capacitance of electrode-skin interface increases path loss significantly when noncontact transmission happens. To solve the problems, a low-power receiver with dual-mode operation is proposed in this paper. The receiver has been implemented in a standard 0.18-mu m CMOS process measurement shows the receiver is fully functional with power consumption < 1.75 mW under 1.2 V supply voltage and compatible with IEEE 802.15.6 HBC layer. The chip size is 1.05 mm(2). Maximum voltage conversion gain can be 85.5 dB. Experimental sensitivity is up to -90 dBm under an information data rate of 164 kb/s. It has been demonstrated that the receiver provides successful text file transmission through human body with the fabricated sensing electrodes.
Invited: Wireless sensor nodes for environmental monitoring in Internet of Things
(2016)
Lu, Ting-Chou
;
Huang, Li-Ren
;
Lee, Yu
;
Tsai, Kun-Ju
;
Liao, Yu-Te
This paper presents a self-sustainable landslide surveillance system that detects hazardous water content level in soils and provides real-time landslide warnings to residents, without requiring wired electricity transmission. A self-powered soil water content sensor was applied as the trigger of alert event. It solves the energy supply problem by an environmental interrupt mechanism, which wakes up the sensor and communication circuits in a sensing node only when the water content in monitored soils exceeds a certain threshold, and thus completely eliminates the need for an ALS node to periodically wake up, sense and communicate. By tightly integrating energy harvesting, environment sensing and circuit wake-up, it may well be the most energy-efficient landslide surveillance system designed to monitor water content in soils in the world.
Invited: Wireless sensor nodes for environmental monitoring in Internet of Things
(2016)
Lu, Ting-Chou
;
Huang, Li-Ren
;
Lee, Yu
;
Tsai, Kun-Ju
;
Liao, Yu-Te
This paper presents a self-sustainable landslide surveillance system that detects hazardous water content level in soils and provides real-time landslide warnings to residents, without requiring wired electricity transmission. A self-powered soil water content sensor was applied as the trigger of alert event. It solves the energy supply problem by an environmental interrupt mechanism, which wakes up the sensor and communication circuits in a sensing node only when the water content in monitored soils exceeds a certain threshold, and thus completely eliminates the need for an ALS node to periodically wake up, sense and communicate. By tightly integrating energy harvesting, environment sensing and circuit wake-up, it may well be the most energy-efficient landslide surveillance system designed to monitor water content in soils in the world.