Browsing by Author "Wey, Chin-Long"

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0.65V-Input-Voltage 0.6V-Output-Voltage 30ppm/degrees C Low-Dropout Regulator with Embedded Voltage Reference for Low-Power Biomedical Systems
(2014-01-01)
Chen, Wei-Chung
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Su, Yi-Ping
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Lee, Yu-Huei
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Wey, Chin-Long
;
Chen, Ke-Horng
120V/ns Output Slew Rate Enhancement Technique and High Voltage Clamping Circuit in High Integrated Gate Driver for Power GaN FETs
(2015)
Yang, Hsiang-An
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Chiu, Chao-Chang
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Lai, Shin-Chi
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Chen, Jui-Lung
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Chang, Chih-Wei
High power density is a key point that power converters endeavor to pursue. However, it is rare that gate driver of power converter can switch under high supply voltage with a fast operation frequency. In this paper, a half-bridge driver with the slew rate enhancement (SRE) technique is proposed and its switching frequency can be increased to 25MHz under a 700V supply voltage. Besides, the proposed high voltage clamping circuit ensures all circuits operating in a safe region without any overvoltage problems in the bootstrap operation. With specifically developed high voltage high speed (HVHS) process, high-side and low-side circuits can be well shielded by the isolation well which is embedded in the level shifter device to minimize chip size.
200nA Low Quiescent Current Deep-Standby Mode in 28nm DC-DC Buck Converter for Active Implantable Medical Devices
(2015)
Chu, Li-Cheng
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Yang, Te-Fu
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Huang, Ru-Yu
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Su, Yi-Ping
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Lin, Chiun-He
the proposed deep-standby mode (DSM) is used in 28nm power management unit (PMU) for long-term usage in active implantable medical devices (AIMD). The PMU can upgrade its normal mode with the proposed embedded auto-cancellation (EAC) technique in order to have high accuracy even if the battery is aging and the PVT variations occur. The test chip fabricated in 28nm CMOS process features low quiescent current of 200nA and output voltage accuracy of 98%. Seamless transition among the DSM and the accurate mode demonstrates both low quiescent current and high accuracy can be achieved in the proposed PMU.
90% Peak Efficiency Single-Inductor-Multiple-Output DC-DC Buck Converter with Output Independent Gate Drive Control
(2015-01-01)
Su, Yi-Ping
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Lin, Chiun-He
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Peng, Shen-Yu
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Huang, Ru-Yu
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Yang, Te-Fu
93% Efficiency and 0.99 Power Factor in Pseudo-linear LED Driver
(2016-01-01)
Chiu, Shao-Wei
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Kuo, Chun-Chieh
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Chuang, Kai-Cheng
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Yang, Wen-Hau
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Chen, Ke-Horng
The proposed pseudo-linear LED driver can effectively solve the serious flicker in conventional linear LED driver (LLD). Besides, it has good electromagnetic interference (EMI) performance similar to that in conventional LLD at high AC input voltage. In the meanwhile, it has high power factor (PF) similar to boost switching regulator (SWR) LED driver at low AC input voltage. Furthermore, owing to the combination of line filter and the active full bridge rectifier, the pseudo-linear LED driver has a compact solution and high efficiency. The test chip was fabricated in 0.5 mu m 500V LDMOS process. Experimental results show 93% high efficiency, 6% total harmonic distortion (THD), and 0.99 PF at the power of 7W.
95% Light-load Efficiency Single-Inductor Dual-Output DC-DC Buck Converter with Synthesized Waveform Control Technique for USB Type-C
(2016)
Yang, Wen-Hau
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Lin, Chiun-He
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Chen, Ke-Horng
;
Wey, Chin-Long
;
Lin, Ying-Hsi
The proposed single-inductor dual-output (SIDO) converter can provide wide range in duty ratio control to convert input voltage 520V to dual output voltages 3.3V and 1.2V when its switching frequency is raised to 10MHz for compact size solution. The proposed synthesized waveform control (SWC) technique can emulate the inductor current without being affected by switching noise. Thus, the minimum allowable duty ratio can be lowered to 6% to meet the requirement of USB-C in one-stage low duty ratio conversion. Moreover, the switching frequency is dynamically decreased by the derived DC loading information from the SWC technique. Not only the output power MOSFET but also the main power MOSFET switch in a load-dependent switching frequency for power saving. 67% more power reduction can be obtained. 95% and 83% efficiency are achieved at light and heavy loads, respectively, when the silicon is limited within 1400 mu m*1350 mu m.
A 20MS/s Buck/Boost Supply Modulator for Envelope Tracking Applications with Direct Digital Interface
(2014)
Yang, Shang-Hsien
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Wey, Chin-Long
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Chen, Ke-Horng
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Lin, Ying-Hsi
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Chen, Jing-Jia
a buck/boost supply modulator (BBSM) is proposed for 4G LTE RF power amplifier (RF-PA) envelope tracking applications. The H-bridges used in non-inverting buck/boost converters are metamorphosed into the current sources and switches of a 4-bit current-steering DAC-like supply modulator. Fast tracking speed is achieved through its inherent open-loop topology, while the direct digital interface provides easy control and integration with digital LTE baseband SoCs. The proposed BBSM is capable of delivering peak power of 2.8W at 20MS/s, with a peak efficiency of 75 %.
A 96%-Efficiency and 0.5%-Current-CrossRegulation Single-Inductor Multiple Floating-Output LED Driver with 24b Color Resolution
(2016)
Yang, Hsiang-An
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Yang, Wen-Hau
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Chen, Ke-Horng
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Wey, Chin-Long
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Lin, Ying-Hsi
A Class-D Amplifier Powered by Embedded Single-Inductor Bipolar-Output Power Module with Low Common Noise and Dynamic Voltage Boosting Technique
(2014-01-01)
Chen, Shin-Hao
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Lin, Kuei-Liang
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Ng, Shao Siang
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Chen, Ke-Horng
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Wey, Chin-Long
This paper proposes a high efficiency Class-D amplifier (CDA) with embedded single-inductor bipolar output (SIBO) power module. The characteristics of SIBO converter\'s bipolar outputs not only suppress equivalent common mode noise but also remove several large external bulky components in conventional boost supply CDA systems. Since bipolar outputs in the SIBO provide independent driving capability, CDA is capable of operating in both single-ended (SE) and bridge-tide load (BTL) configurations. Furthermore, the proposed dynamic voltage boosting (DVB) technique adjusts the SIBO output voltage level according to the CDA\'s output level with 5% power efficiency improvement. Peak total harmonic distortion plus noise (THD+N) performance is 0.012%. Peak power efficiency of SIBO and CDA are 89% and 93.2%, respectively.
A Continuous Opto-Electronic Sensor for Blood Pressure Monitoring with Real-Time System
(2017-01-01)
Kao, Yung-Hua
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Chao, Paul C. -P.
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Wey, Chin-Long
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A new continuous wireless opto-electronic blood pressure (BP) sensor is successfully developed by this study. The BP device introduces the principle of photoplethysmograph (PPG) to sense the change of intravascular blood volume and calculate the BP. The real-time system adopts a LEDs of red/infrared light with a wavelengths of 660 and 905 nm. The analog front-end (AFE) circuit contains a pre-amplifier, a band-pass filter, a programmable gain amplifier (PGA), a microprocessor and a wireless module. A mobile phone is also used to display continuous BPs and record statistical analysis/results for users. The passband of filter is from 0.3 to 7.2 Hz. The PGA of adjustable gain are 8 channel. As results, 10 subjects in the experimental validation, in which the obtained BPs are compared with the results from a commercial BP monitor by OMRON. The maximum error of experimental results is 6 mmHg, which is less than 8 mmHg conforming to the requirement by the Advancement of Medical Instrumentation (AAMI).
A Digital Low-Dropout-Regulator with Steady-State Load Current (SLC) Estimator and Dynamic Gain Scaling (DGS) Control
(2016)
Lin, Jian-He
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Tsou, Wen-Jie
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Chen, Ke-Horng
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Wey, Chin-Long
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Lin, Ying-Hsi
conventional digital low dropout (D-LDO) regulator usually suffers from the drawback of long settling time during transient response due to the usage of shift register architecture. In this paper, the proposed D-LDO regulator can observe the output voltage variations during load transient time to predict the load current for fast transient response. Near optimum turn on power MOSFET in steady state can be derived by the proposed steady-state load current (SLC) estimator while the dynamic gain scaling (DGS) technique can improve transient response and avoid limiting cycle oscillation (LCO) problem. Test chip was designed in 0.18 mu m CMOS process. Simulation results showed the transient response time can be reduced by 88% from 920ns to 115ns.
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 Dual-Level Dual-Phase Pulse-Width Modulation Class-D Amplifier with 0.001% THD, 112 dB SNR
(2014-01-01)
Yang, Shang-Hsien
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Yang, Yuan-Han
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Chen, Ke-Horng
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Hung, Chung-Chih
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Wey, Chin-Long
this paper presents a dual-level dual-phase pulse-width modulation (DLDP PWM) Class-D audio amplifier circuit which enhance amplifier linearity and reduce distortion. The proposed DLDP PWM Class-D audio amplifier includes two sets of non-overlapping triangular waves, each at its respectful offset levels. Each set of triangular waves is composed of two 180 degrees out-of-phase triangular waves. The differential power stage consists of 8 power transistors, with voltage swings up to +/- 6V. Simulated results shows that the proposed DLDP PWM Class-D audio amplifier features an SNR up to 105 dB, and the THD is suppressed below 0.001 %, with the 3rd harmonic below -102 dBV.
A Fast Hysteretic Buck DC-DC Converter with Start-up Overshoot Suppression Technique
(2012-01-01)
Chang, Kun-Chun
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Wey, Chin-Long
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電機學院
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College of Electrical and Computer Engineering
The voltage-mode hysteretic converter is one of ripple-based regulators. The converter has the salient features of fast transient response, good conversion efficiency, and simple architecture. However, the major drawbacks include large voltage ripple caused by propagation delay path and excess overshoot voltage during the start-up period. This paper presents an overshoot suppression technique uses two-phase PMOS transistors to optimize the solution among the overshoot voltage, transistor size, and conversion efficiency. There exists a design trade-offs between start-up overshoot voltage and settling time. Results show that, with the proposed suppression technique, the overshoot voltage is reduced from 340mV to 74.4mV. However, the settling time is increased from 15.1us to 21.74 us.
A Low Quiescent Current and Cross Regulation Single-Inductor Dual-Output Converter with Stacking MOSFET Driving Technique
(2017-01-01)
Ma, Yu-Sheng
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Yang, Wen-Hau
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Lin, Yen-Ting
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Chen, Hsin
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Lin, Li-Chi
the stacking MOSFET structure composed of low-voltage devices suffers from deteriorated transient response or large footprint area when capacitor-free or dominant pole compensation low dropout (LDO) regulator biases the driver. Due to self-stabilized feature, the proposed stacking MOSFET driving (SMD) technique effectively drives the power stage and greatly reduces noise interference from the noisy node to achieve low cross regulation (CR) in the single-inductor dual-output (SIDO) converter. Moreover, two inherent low dropout (LDO) regulators in the SMD technique completely regulate two outputs with low quiescent current at no load condition. Experimental results show the tested chip fabricated in 0.25 mu m process with low cross regulation of 0.015mV/mA and ultra-low quiescent current of 5 mu A at no load condition.
A new adaptive front-end circuit for high-resolution magnetic scales
(2015)
Chien, Ping-Chieh
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Kao, Yung-Hua
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Chen, Hong-Yang
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Huang, Jing-Hao
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Chao, Paul C. -P.
A new front-end readout circuit design using an adaptive amplifier is proposed by this study for magnetic and optical scales. The purpose of the integrated chip (IC) designed herein is to provide the magnetic/optical scales the capability of sensing translational or angular positions of an object in largely-arying amplitudes with high resolutions. Toward this end, a new front-end readout circuit is designed with two adaptive programmable gain amplifiers (PGAs) and two analog-to-digital converters (ADCs). The PGA is particularly designed to accept signals up to 1 MHz from MR sensor signals, which could be one of three voltage levels: 120 mVp-p, 250 mVp-p, 330 mVp-p. The resulted power consumption is 56 mW. The chip also includes a successive approximation register (SAR) ADC having two 12-bit channels for sine-to-digital conversions. The linearity of ADC achieve satisfactory performance (+/- 1LSB) in the input range of 0.5 similar to 2.5V in Vp-p. The chip was fabricated by the TSMC 0.35-icron 2P4M CMOS technology for verification.
A New Automatic Readout Circuit for a Gas Sensor with Organic Vertical Nanojunctions
(2016)
Chen, Hung-Che
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Kao, Yung-Hua
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Chao, Paul C. -P.
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Wey, Chin-Long
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電子工程學系及電子研究所
The design of the proposed readout circuit provides benefits of detection speed, portability, low-cost and less human operational errors compared with the measurement by traditional instruments. Thus the added value is brought for bio-sensors and applied in home care. A novel readout circuit for a gas sensor based on an organic diode with vertical nano junctions (VNJ) is proposed in this study. There are seven parts included in the readout system. First part is a preamplifier, second part is a peak-detect-and-hold circuit, third part is a divider, fourth part is the saturation detector, fifth part is the auto-reset circuit, sixth part is a logic gate and a buffer, seventh part is a micro-processor control unit (MCU). STM32 is the CPU of proposed MCU by ALIENTEK. The ADC of MCU is used to transform the output data of readout circuit. The designed circuit is accomplished by Taiwan Semiconductor Manufacturing Company (TSMC) 0.35 mu m 2P4M 3.3 V mixed - signal CMOS process, the area of chip is 0.74x0.75 mm(2). Finally, the differences between experimental results with post simulation results in 10 ppb similar to 3 ppm of ammonia, the differences are within 7.24%. The sensing system is able to detect minimum ammonia concentration of 10 ppb, while the maximum one reaches around 3 ppm.
A New Cuffless Optical Sensor for Blood Pressure Measuring with Self-Adaptive Signal Processing
(2016-01-01)
Kao, Yung-Hua
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Chao, Paul C-P
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Tu, Tse-Yi
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Chiang, Keng-Yueh
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Wey, Chin-Long
A new cuffless, wireless optical blood pressure (BP) sensor is successfully developed by this study. This device employs the technique of photoplethysmograph (PPG) to read out in real time the intravascular blood volume change and then to calculate BP. The system utilizes a red-light LED with a wavelengths of 660 nm. The readout circuit includes a pre-amplifier, a band-pass filter, a programmable gain amplifier (PGA), an Arduino unit for calculation and a Bluetooth module for wireless communication. A notebook or a mobile phone is also used to display continuous BPs and conducts statistical analysis/results. The passband is from 0.3 to 3.4 Hz. The range of adjustable gain are from 60 to 80 dB. Measured PPGs of different subjects can be auto-adjusted with varied gain by a PGA with a pre-designed digital circuit. In results, the signal-to-noise ratio (SNR) is improved for accurate estimates on BPs. 8 subjects participated in the experimental validation, in which the obtained BPs are compared with the results from a commercial blood pressure monitor by OMRON. The maximum error of experimental results is +/- 6 mmHg, which is less than 8 mmHg conforming to the requirement by the Advancement of Medical Instrumentation (AAMI). This study pioneers to report stable, accurate estimates on BPs by a cuffless optical hand-held device.
A New Reflective PPG LED-PD Sensor Module for Cuffless Blood Pressure Measurement at Wrist Artery
(2017-01-01)
Kao, Yung-Hua
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Chao, Paul C. -P.
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Hung, Yueh
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Wey, Chin-Long
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電機工程學系
A new reflective photoplethysmography (PPG) sensor module is developed with effort to optimize the distances between light emitting diodes (LEDs) and a photodiode (PD) in the proposed module for precision cuffless, non-invasive blood pressure (BP) measurement based on PPG of wrist artery. In the developed module, four LEDs with different wavelengths of 530 nm, 660 nm, 850 nm, 940 nm are included. A new optical simulation model based on Beer-Lambert's law is established, which include LEDs, PD, epidermis, dermis, subcutaneous tissue and pulsating arteries. The distances between LEDs and PD are optimized to maximize the signal-to-noise ratio of the PPG received by PD for higher precision of the predicted BPs from arterial PPG. The results show that the optimal distance is around 2 mm for detecting arterial pulsation by wavelengths of 850 and 950 nm. Experiments were also conducted, showing favorable results of BP measurements.
A Portable, Wireless Photoplethysomography Sensor for Assessing Health of Arteriovenous Fistula Using Class-Weighted Support Vector Machine
(2018-11-01)
Chao, Paul C. -P.
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Chiang, Pei-Yu
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Kao, Yung-Hua
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Tu, Tse-Yi
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Yang, Chih-Yu
A portable, wireless photoplethysomography (PPG) sensor for assessing arteriovenous fistula (AVF) by using class-weighted support vector machines (SVM) was presented in this study. Nowadays, in hospital, AVF are assessed by ultrasound Doppler machines, which are bulky, expensive, complicated-to-operate, and time-consuming. In this study, new PPG sensors were proposed and developed successfully to provide portable and inexpensive solutions for AVF assessments. To develop the sensor, at first, by combining the dimensionless number analysis and the optical Beer Lambert's law, five input features were derived for the SVM classifier. In the next step, to increase the signal-noise ratio (SNR) of PPG signals, the front-end readout circuitries were designed to fully use the dynamic range of analog-digital converter (ADC) by controlling the circuitries gain and the light intensity of light emitted diode (LED). Digital signal processing algorithms were proposed next to check and fix signal anomalies. Finally, the class-weighted SVM classifiers employed five different kernel functions to assess AVF quality. The assessment results were provided to doctors for diagonosis and detemining ensuing proper treatments. The experimental results showed that the proposed PPG sensors successfully achieved an accuracy of 89.11% in assessing health of AVF and with a type II error of only 9.59%.