A5022744560- Analog and Mixed-Signal Circuit Design
- CCD and CMOS Imaging Sensors
- GaN-based semiconductor devices and materials
- Advancements in Semiconductor Devices and Circuit Design
- Ga2O3 and related materials
- Advancements in PLL and VCO Technologies
- Advanced DC-DC Converters
- ZnO doping and properties
- Multilevel Inverters and Converters
- Low-power high-performance VLSI design
- Wireless Power Transfer Systems
- Silicon Carbide Semiconductor Technologies
- Radio Frequency Integrated Circuit Design
- Acoustic Wave Resonator Technologies
- Electrostatic Discharge in Electronics
- Advanced Sensor and Energy Harvesting Materials
- Electromagnetic Compatibility and Noise Suppression
- Plasma Diagnostics and Applications
- Metal and Thin Film Mechanics
- Advanced Memory and Neural Computing
- Induction Heating and Inverter Technology
- Ultrasound Imaging and Elastography
- Semiconductor Quantum Structures and Devices
- Ultrasonics and Acoustic Wave Propagation
- Neural Networks and Reservoir Computing
Fuzhou University
2023-2025
Songshan Lake Materials Laboratory
2021-2022
Guilin University of Electronic Technology
2022
National Central University
2020-2021
National Cheng Kung University
2019
Abstract Ultraviolet‐C light‐emitting diodes (UVC‐LEDs) have great application in pathogen inactivation under various kinds of situations, especially the fight against COVID‐19. Unfortunately, its epitaxial wafers are so far limited to a size 2 inches, which greatly increases cost massive production. In this work, 4‐inch crack‐free high‐power UVC‐LED wafer is reported. This achievement relies on proposed strain‐tailored strategy, where 3D 2D (3D‐2D) transition layer introduced during...
Abstract In this work, based on physical vapor deposition and high-temperature annealing (HTA), the 4-inch crack-free high-quality AlN template is initialized. Benefiting from crystal recrystallization during HTA process, FWHMs of X-ray rocking curves for (002) (102) planes are encouragingly decreased to 62 282 arcsec, respectively. On such an template, ultra-thin with a thickness ~700 nm grown by MOCVD shows good quality, thus avoiding epitaxial lateral overgrowth (ELOG) process in which...
This article presents a dynamic range (DR) enhanced discrete-time delta–sigma modulator (DTDSM) applied to the Internet of Things (IoT). It is based on an asynchronous 1.5-bit successive-approximation-resister (SAR) quantizer and tri-level feedback capacitive digital-to-analog converter (CDAC), eliminating element matching (DEM) overhead. The proposed DR enhancement (DRE) technique variable threshold ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML"...
In the present work, a single-crystalline epitaxial nonpolar a-plane AlN film with in-plane two-folder symmetries was successfully achieved on an r-plane sapphire substrate, by combining physical vapor deposition and high-temperature annealing technique. Moreover, varying thickness, evolution of crystalline quality structure were systematically investigated using X-ray diffraction, Raman spectroscopy, atomic force microscopy. The much improved treatment. Most importantly, when thickness...
This paper introduces a discrete-time delta-sigma ADC for the Internet of Things (IoT) applications. It utilizes second-order 4-bit successive approximation register (SAR) quantizer architecture based on oversampling technique to ensure sufficiently high SQNR. Additionally, dynamic weighted averaging (DWA) is employed achieve good feedback CDAC linearity. System-level analysis and circuit implementation are introduced in detail. The implemented prototype this manufactured using 180 nm CMOS...
In order to achieve the low cost and more compact size, primary side-regulation technology is widely used in power applications, output voltage can be estimated by an auxiliary winding without secondary-side feedback circuit. For single-stage flyback converter, no algorithm suitable for both DCM CCM. this paper, a novel digital controlled sampling proposed converter. This scheme uses midpoint method estimate current of switch discontinuous conduction mode (DCM) continuous (CCM), control...
Abstract A low‐power multibit delta–sigma modulator (DSM) based on a passive and unattenuated summation scheme is proposed. The circuit achieves multiplication of the voltage signal carried capacitor through bidirectional sampling technique, thereby compensating for inherent attenuation caused by summation, which eliminates need an active operational transconductance amplifier (OTA) to achieve perfect summation. Here, second‐order DSM 4‐bit first‐order noise‐shaping (NS) SAR quantizer...
The paper presents the design of a linear dimmable flicker-free LED driver. driver consists preamplifier in series with regulator and forms drive loop string. output current pre-amplifier adjusts adaptively amplitude AC input bus therefore, voltage across remains at minimum required to maintain desired string while reducing power variation on LEDs. In addition, detects provides constant LEDs based fluctuations voltage, which effectively eliminates flicker maintains high system efficiency....
In the field of delta-sigma modulators, reducing system power consumption without sacrificing accuracy has become a challenge. The summing circuit, as main part modulator, consumes significant amount in active summing, although it can achieve perfect summation. On other hand, passive circuits have low but cause attenuation results. objective this article is to explore how summation manner. This proposes low-power multi-bit modulator based on and attenuationless scheme. circuit achieves...
This paper presents a low-power capacitive-to-digital converter (CDC) based on incremental delta-sigma modulator. It utilizes zoom-in sensing capacitor that is insensitive to parasitic capacitance, improving the capacitance resolution. The use of high-gain, PVT-robust current-starved OTA and dynamic bias comparator enhances efficiency system. An ultra-low-power circuit integrated into system, further integration efficiency. proposed CDC fabricated using 180 nm CMOS process. Operating at 1.2...
A voltage reference is indispensable in Integrated Circuits. To improve the limited linear output range and energy efficiency of a reference, we innovatively propose switched-capacitor-based programmable scheme employing inverter-based OTAs to reduce power consumption, simultaneously using novel Correlated Level Shifting (CLS) technique (without active overhead) enhance OTA’s DC gain integral gain. Experimented with SMIC 180 nm CMOS technology, scheme-based realizes programable from 266 995...
With LCC resonant circuit as the topological high- voltage charging power supply, commonly used modulation methods are pulse-frequency (PSM) and phase shift (PFM). Aiming at problem of wide frequency range, low utilization magnetic parts when PFM, narrow soft switching range PSM, a functional relationship between output current is established, PSM-PFM hybrid strategy proposed based on characteristics. This control uses PSM light load to increase speed capacitor without increasing stress,...
In this work, the epitaxial semipolar (11-22) AlN was prepared on nonpolar m-sapphire substrate by combining sputtering and high-temperature annealing. According to our systematic measurements analysis from XRD, Raman spectra, AFM, evolution of crystalline structure morphology investigated upon increasing thickness annealing duration. The operation intensively resets lattice improves quality. By varying film thickness, contribution AlN-sapphire interface quality parameters during process...
The article presents a novel high-voltage power driver circuit that can be used to drive variety of capacitive or resistive loads, applied for medical ultrasound pulse generators. output stage this employs pair stacked inverters and the active floating gate bias circuit, which adaptively switch devices between low high voltage conditions. Therefore, generate rail-to-rail signals within safe operating range. architecture has been implemented 100-pF capacitor in parallel with 1-K ohm resistor...
We show the structural and optical properties of non-polar a -plane GaN epitaxial films modified by Si ion implantation. Upon gradually raising fluences from 5 × 10 13 cm −2 to 15 , n-type dopant concentration increases 4.6 18 4.5 20 while generated vacancy density accordingly raises 3.7 3.8 . Moreover, despite that implantation enhances disorder, structure implanted region is still well preserved which confirmed Rutherford backscattering channeling spectrometry measurements. The monotonical...
This study presents a dynamic amplifier with high energy efficiency and gain suitable for delta-sigma modulator based on the floating-inverter (FIA), in-depth analysis of existing FIA its improved structure, simulation verification. Compared other structures, proposed has better compromise in terms power consumption stability, which was designed simulated using SMIC 180 nm CMOS technology. Under 1.2 V supply, closed-loop direct current (DC) output swing were about 104 dB ±380 mV,...
In the field of delta-sigma modulators, reducing system power consumption without sacrificing accuracy has become a challenge. The summing circuit, as main part cascade-of-integrator-in-feedforward modulator, consumes significant amount in active summing. On other hand, passive circuits have low but can cause attenuation results. This article proposes low-power multi-bit modulator based on and attenuationless summation scheme. circuit achieves multiplication voltage signal carried capacitor...
Discrete-time delta-sigma modulators (DTDSM) have excellent energy efficiency in low bandwidth, high dynamic range, and precision applications, making them ideal for battery-powered IoT sensor devices with bandwidths within the kHz range. They achieve signal-to-noise ratio (SNR) range (DR) primarily through higher-order loops, higher OSR, multi-bit quantizers, multi-stage noise-shaping (MASH). However, loops can decrease maximum stable amplitude (MSA), OSR increases system power consumption,...
This article proposes a novel driver architecture applied in GaN power transistors, suitable for high-speed and high-voltage half-bridge or full-bridge drivers. The overall circuit design uses only E-mode D-mode transistors. of the high-side employs EED structure (E-mode/E-mode/D-mode), therefore, gate highside transistor can be directly driven by low-voltage signal without using traditional level-shifters, simplifying design. low-side stacking two devices to isolate output pulses from drive...
This paper proposes a novel high-end driver, which can directly drive the switch from low-voltage pulse signal without level conversion circuit, effectively reduce complexity of circuit design. The performance driver has been verified by being integrated into high-voltage buck converter. Preliminary simulation results show that when input voltage is 24 to 36V and operating switching frequency 1 MHz, output converter maintain stable 5V with ripple less than 0.6 mV.
Ultraviolet-C light-emitting diodes (UVC-LEDs) have great application in pathogen inactivation under various kinds of situations, especially the fight against COVID-19. Unfortunately, its epitaxial wafers are so far limited to 2-inch size, which greatly increases cost massive production. In this work, we report 4-inch crack-free high-power UVC-LED wafer. This achievement relies on a proposed strain-tailored strategy, where three-dimensional two-dimensional (3D-2D) transition layer is...