Browsing by Author "Lu, Shao-Yung"

Now showing 1 - 11 of 11

A 2.2 mu W,-12 dBm RF-Powered Wireless Current Sensing Readout Interface IC With Injection-Locking Clock Generation
(2016-07)
Lin, Fu-To
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Lu, Shao-Yung
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Liao, Yu-Te
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電機學院
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College of Electrical and Computer Engineering
This paper presents a wireless-powering current-sensing readout system on a CMOS platform for portable electrochemical measurement. The wireless sensing system includes energy-efficient power management circuitry, a sensor readout interface, and a backscattering wireless communication scheme. For power-and-area-constrained bio-sensing applications, the proposed readout circuitry incorporates an ultra-low-power potentiostatic system that generates a current according to the electrochemical reaction, as well as an oscillator-based time-to-digital converter instead of a voltage-domain analog-to-digital converter. To avoid a bulky battery and power-hungry clock reference, the chip is wirelessly powered and injection-locked by the modulated radio waves, which includes a 918 MHz carrier signal mixed with a 3.2 MHz modulated signal. The chip, implemented using a 0.18-mu m CMOS process, occupies a silicon area of 1 mm(2). The proposed design achieves a sensitivity of 289 Hz/nA and an R-2 linearity of 0.997 over a current range of 200 nA while consuming 2.2 mu W at a supply voltage of 0.8 V. The chip, integrated with a PCB antenna, has minimum sensitivities of -12 dBm and -25 dBm for RF-powering and injection-locking mechanisms, respectively.
A 45 mu W, 9.5MHz Current-Reused RC Oscillator Using a Swing-Boosting Technique
(2017-01-01)
Lu, Shao-Yung
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Liao, Yu-Te
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資訊工程學系
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Department of Computer Science
This paper presents a differential relaxation oscillator that uses swing-boost and current-reused techniques. Output swing boosting is adopted to improve noise performance, and current-reused architecture reduces the power consumption of the oscillator. Since oscillation frequency is defined by the resistor and capacitor, combining opposite temperature coefficient resistors helps eliminate temperature-caused frequency drifts. The proposed RC oscillator is fabricated using 0.18 mu m standard CMOS technology. The design achieves an FOM of 161.5 dBc/Hz with a phase noise of -108.5 dBc/Hz at 100kHz offset and an Allan deviation floor of 5.2 ppm at a 2-second integral window while consuming 45 mu W. The measured temperature coefficient is 307 ppm/degrees C in the temperature range of -20-100 degrees C, and the measured period jitter is 10.5 ps(rms).
A 46 mu W, 8.2MHz Self-threshold-tracking Differential Relaxation Oscillator with 7.66psrms Period Jitter and 1.56ppm Allan Deviation Floor
(2018-01-01)
Lu, Shao-Yung
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Liao, Yu-Te
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電機工程學系
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Department of Electrical and Computer Engineering
This paper presents an 8.2MHz relaxation oscillator with swing boosting and self threshold tracking, designed to improve both period jitter and frequency stability. A self-threshold-tracking loop ensures the switching threshold is kept in a constant, reducing the frequency uncertainty from process, temperature and supply voltage variations. Implemented in a 180nm CMOS process, the design achieves a period jitter of 7.66psrms, an Allan deviation floor of 1.56ppm, a temperature coefficient of 123ppm from-20 to 100 degrees C, and an FOM of 160.9dBc/Hz while only consuming 46.3 mu W. The power efficiency of the design is 5.6kHz/nW.
A High-Efficiency Power Management IC with Power-Aware Multi-path Rectifier for Wide-Range RF Energy Harvesting
(2017-01-01)
Lin, Shu-Hsuan
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Kuo, Chen-Yi
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Lu, Shao-Yung
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Liao, Yu-Te
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電機工程學系
A highly-integrated CMOS power-management system with wide-range RF for ultra-high frequency (UHF) wireless energy harvesting is presented. To avoid environment-caused sudden power loss and to scavenge energy efficiently, the proposed power management system adopts power-aware rectifier architecture and adaptive DC-DC conversion ratios according to the input power level. The proposed system was fabricated in a 0.18-mu m CMOS process. The system achieved a peak RF/DC conversion efficiency of 59%, a sensitivity of -11.6dBm, and a 13.5dB RF input range for at least 20% power efficiency at a 100K Omega load. At the high input power region (>-9dBm), the proposed architecture improves about 15% efficiency when compared to a conventional rectifier followed by a linear regulator. The peak efficiency of the entire system is 37%.
A Low-Power Wireless Bondwire Inertial Sensor System
(2015)
Huang, Shih-Chieh
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Lu, Shao-Yung
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Cheng, Fu-Yuan
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Tsai, Tsung-Heng
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Liao, Yu-Te
This paper presents the design and implementation of a fully-integrated CMOS accelerometer using bondwires as sensing devices without Micro Electro-Mechanical Systems (MEMS) processes. The model and analysis of bondwire inertial sensors are provided for further implementation of low-power and low-noise accelerometers. Finite element method (FEM) simulation is performed to verify the concept and model. This paper also proposes a closed-loop readout interface that suppresses the in-band noise and reduces both design complexity and power consumption. The bondwire accelerometer is fabricated in a 0.18 mu m CMOS process, achieves a 33 mV/g linear transducer gain within a 5 kHz bandwidth, and consumes 9 mW.
A Low-Power, Differential Relaxation Oscillator With the Self-Threshold-Tracking and Swing-Boosting Techniques in 0.18-mu m CMOS
(2019-02-01)
Lu, Shao-Yung
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Liao, Yu-Te
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電機工程學系
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Department of Electrical and Computer Engineering
This paper presents a fully integrated, 8.2-MHz relaxation oscillator with a self-threshold-tracking loop and swing-boosting technique for improving its long-term frequency stability and noise performance. The proposed latch-based relaxation oscillator increases the transition speed to reduce the static power consumption. To decrease the process-voltagetemperature dependence, we propose a self-threshold-tracking loop to ensure that the transition point of the inverter-based comparator is set to a fixed ratio of the supply voltage. In addition, the comparator delay can be compensated by the tracking loop, relaxing the requirements of comparator power consumption. The design is implemented in a 0.18-mu m CMOS process. The design achieves a period jitter of 7.66 psrms, the phase noise of -109 dBc/Hz at an offset frequency of 100 kHz, and an Allan deviation noise floor of 1.56 ppm. The resultant figure of merit is 160.8 dBc/Hz, while only consuming 46.3 mu W. The power efficiency of the design is 5.6 kHz/nW. As for the supply sensitivity, the design achieves 0.9 %/0.1 V, which is 10x lower than the design with no compensation loop. The measured temperature coefficient of the proposed oscillators is 123 ppm/degrees C from -20 degrees C to 100 degrees C without any trimming process.
A Microwatt Dual-Mode Electrochemical Sensing Current Readout With Current-Reducer Ramp Waveform Generation
(2019-12-01)
Chen, Yi-Chia
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Lu, Shao-Yung
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Liao, Yu-Te
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電機工程學系
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Department of Electrical and Computer Engineering
An electrochemical sensing chip with an integrated current-reducer pattern generator and a current-mirror based low-noise chopper-stabilization potentiostat circuit is presented. The pattern generator, utilizing the current reducer technique and pseudo resistors, creates a sub-Hz ramp signal for the cyclic voltammetric (CV) measurement without large-size passive components. The proposed design adopts the chopper-stabilization and low-noise biasing technique for the potentiostat and a counter-based time-to-digital converter to reduce the amplitude noise effects and to convert the sensing current signal to digital codes for further data processing. The design is fabricated using a 0.18-m CMOS process and achieves a 41pA current resolution in the current range of 5A while maintaining the R-2 linearity of 0.998. The system consumes 16W from a 1.2V supply when a 5A sensing current is detected. The power efficiency of the readout interface is 0.31, and the sensing current dynamic range is 108dB. The design is fully integrated into a single chip and is successfully tested in the dual-mode (CA/CV) measurements with commercial gold electrodes in a potassium ferricyanide solution in sub-millimolar concentrations.
A Power-efficient, Bi-directional Readout Interface Circuit for Cyclic-voltammetry Electrochemical Sensors
(2019-01-01)
Chen, Yi-Chia
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Lu, Shao-Yung
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Tsai, Jui-Hsiang
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Liao, Yu-Te
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電機工程學系
This paper presents an electrochemical sensing front-end circuit with a cyclic voltammetry potentiostat. To accommodate a large and bidirectional current sensing range for the current-mirror based potentiostat, a constant offset current is added. With the technique of chopper-stabilization, the flicker noise of the readout circuit is successfully reduced. A charge-based oscillator is also proposed in this paper to convert the current into a frequency for further data readout. The proposed readout IC was fabricated in a 0.18 mu m, 1.2V CMOS process and the current range is -2 mu A similar to 12.2 mu A, the R-2 linearity of 0.992, with a minimum detectable current of 3.1nA. The dynamic current range is 73.2dB whereas the chip consumes 40.5 mu W at a maximum sensing current of 12.2 mu A.
A Reconfigurable, Pulse-shaping Potentiometric Readout System for Bio-Sensing Transistors
(2019-01-01)
Lu, Shao-Yung
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Shan, Siang-Sin
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Yang, Jiancheng
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Chang, Chin-Wei
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Ren, Fan
This paper presents a new multi-modality readout system for potentiometric electrochemical sensors. The design adopts a pulse modulation at the gate and drain of the Bio-FET sensors to reduce the effects of charge accumulation between the surface of the electrodes and the ion analytes. The adjustable duration and amplitude of stimuli signals provide flexibility for different biosensing applications and a wide range of detectable concentration. Also, an oscillator-based architecture is proposed for digitization and integration. The counting time can be adjusted to enhance the resolution of the readout system. The proposed potentiometric sensing system was tested with 0.1-10 mM Potassium Ferricyanide (K-3[Fe(CN)(6)]), and the results are interpreted in the micro-LCD on the board. The design offers the opportunity for a handheld medical device with fast and real-time monitoring of biomarkers and ion analytes.
Design and Study of a Portable High-frequency Ventilator for Clinical Applications
(2019-01-01)
Lu, Shao-Yung
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Lin, Hau
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Kuo, Hsu-Tah
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Wu, Chien-Liang
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Wu, Wen-Jui
Treatment costs for ventilator-dependent patients are a substantial burden not only for their family but also for medical systems in general. Recently, using high-frequency ventilators have been shown to reduce the risk of lung injury through low-volume airflow. However, the machines used today remain bulky, costly, and only for use in hospital settings. To provide intermediate therapy for patients between hospitalization and complete discharge, a portable, light-weight high-frequency ventilator is an urgent need. This work presents the design of a portable high-frequency ventilator and a study of its practicality for further clinical medical applications. Through the integration of advanced electronics and mechanical instruments, we develop a portable high-frequency ventilator with reconfigurable oxygen flow rate, applied pressure, and air volume for the needs of individual patients. A miniaturized portable high-frequency ventilator with digital controller and feedback system for stabilization and precision control is implemented. The efficiency of CO2 washout using the proposed ventilator has been demonstrated in animal trials.
Wirelessly-Powered Printed Temperature Sensor with an Ultra-Low-Power and High-Sensitivity CMOS Readout IC
(2019-01-01)
Lu, Shao-Yung
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Wu, I-Feng
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Liao, Ying-Chih
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Liao, Yu-Te
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電機工程學系
This paper presents a wirelessly-powered high-sensitivity printed temperature sensor (TS). The proposed system consists of a -17dBm sensitivity RF-DC conversion circuit, a 2.2 mu W readout interface, and a printed NiO thermistor sensor. The 1 mm(2) printed NiO film has a good sensitivity index (B value) of 4000 K, but has high resistance (M Omega). The conventional readout system has difficulty detecting small resistance changes in the large thermal resistance range while only consuming a few microwatts, which is a need for enabling RF-power sensors remotely. A low-noise readout IC was designed to convert the resistance changes to digital codes. The proposed TS achieves a resolution of 0.04 degrees C/code in a temperature range of -20 degrees C to 90 degrees C, and measurement deviation within +/- 1.1%, while consuming only 2.2 nJ per conversion.