This paper proposes a technique that uses the number of oscillation cycles (NOC) of a VCO-based comparator to set multiple adaptive bypass windows in a 12-bit successive approximation register (SAR) analog-to-digital converter (ADC). The analysis of the number of bit cycles, power and static performance shows that three adaptive bypass windows reduce power consumption, and decrease DNL and have similar

Realizing the layouts of analog/mixed-signal (AMS) integrated circuits (ICs) is a complicated task due to the high design flexibility and sensitive circuit performance. Compared with the advancements of digital IC layout automation, analog IC layout design is still heavily manual, which leads to a more time-consuming and error-prone process. In recent years, significant progress has been made in automated

FMCW radars with high resolution necessities the generation of highly linear, low phase noise, and low spur chirp signals with large bandwidth and a short modulation period. This paper reviews recent research progress on silicon-based FMCW signal generators, identifies advances in architecture, fundamental design, performance analysis, and applications of the FMCW synthesizer.

A 30 MHz voltage-mode controlled buck converter with fast transient responses is presented. An improved differential difference amplifier (DDA)-based Type-III compensator is proposed to reduce the settling times of the converter during load transients, and to achieve near-optimal transient responses with simple PWM control only. Moreover, a hybrid scheme using a digital linear regulator with automatic

Digital to analog converters (DAC) play an important role as a bridge connecting the analog world and the digital world. With the rapid development of wireless communication, wideband digital radar, and other emerging technologies, better performing high-speed high-resolution DACs are required. In those applications, signal bandwidth and high-frequency linearity often limited by data converters are

Granular power management in a power-efficient system on a chip (SoC) requires multiple integrated voltage regulators with a small area, process scalability, and low supply voltage. Conventional on-chip analog low-dropout regulators (ALDOs) can hardly meet these requirements, while digital LDOs (DLDOs) are good alternatives. However, the conventional DLDO, with synchronous control, has inherently slow

With the development of multi-band wireless communication and the increasing data transmission rate, the circulator as an antenna interface must be able to work in multiple frequency bands and provides large bandwidth. It presents a high challenge to the design of circulators, especially the active quasi-circulators. In this survey, we review the representative active quasi-circulators and summarize

The successive approximation register (SAR) is one of the most energy-efficient analog-to-digital converter (ADC) architecture for medium-resolution applications. However, its high energy efficiency quickly diminishes when the target resolution increases. This is because a SAR ADC suffers from several major error source, including the sampling kT / C noise, the comparator noise, and the DAC mismatch

CMOS analog and mixed-signal phase-locked loops (PLL) are widely used in varies of the system-on-chips (SoC) as the clock generator or frequency synthesizer. This paper presents an overview of the AMS-PLL, including: 1) a brief introduction of the basics of the charge-pump based PLL, which is the most widely used AMS-PLL architecture due to its simplicity and robustness; 2) a summary of the design

Au80Sn20 alloy is a widely used solder for laser diode packaging. In this paper, the thermal resistance of GaN-based blue laser diodes packaged in TO56 cans were measured by the forward voltage method. The microstructures of Au80Sn20 solder were then investigated to understand the reason for the difference in thermal resistance. It was found that the microstructure with a higher content of Au-rich

In this paper, drain current transient characteristics of β -Ga 2 O 3 high electron mobility transistor (HEMT) are studied to access current collapse and recovery time due to dynamic population and de-population of deep level traps and interface traps. An approximately 10 min, and 1 h of recovery time to steady-state drain current value is measured under 1 ms of stress on the gate and drain electrodes

This study proposes a new generation of floating gate transistors (FGT) with a novel built-in security feature. The new device has applications in guarding the IC chips against the current reverse engineering techniques, including scanning capacitance microscopy (SCM). The SCM measures the change in the C–V characteristic of the device as a result of placing a minute amount of charge on the floating

The defect properties in d -electron containing materials will be strongly influenced by the non-negligible on-site Coulomb interactions. However, this has been omitted in the current widely adopted standard first-principles calculations, such as LDA, leading to a large deviation of calculated results. Therefore, as a comparative case study, in this paper the defects of CdTe are investigated by first-principles

A novel 4H-SiC trench MOSFET is presented and investigated by simulation in this paper. The device features an integrated Schottky barrier diode and an L-shaped P + shielding region beneath the gate trench and aside one wall of the gate trench (S-TMOS). The integrated Schottky barrier diode works as a free-wheeling diode in reverse recovery and reverse conduction, which significantly reduces reverse

The purpose of this work is to analyze the electrical properties of the metal–semiconductor contact (MSC) in the framework of the theory of complex systems. The effect of inhomogeneity of the different microstructures: polycrystalline, monocrystalline, amorphous metal–semiconductor contact surface is investigated, considering a Schottky diode (SD) as a parallel connection of numerous subdiodes. It

Global data traffic is growing rapidly, and the demand for optoelectronic transceivers applied in data centers (DCs) is also increasing correspondingly. In this review, we first briefly introduce the development of optoelectronics transceivers in DCs, as well as the advantages of silicon photonic chips fabricated by complementary metal oxide semiconductor process. We also summarize the research on

Traditional magnetically coupled resonant wireless power transfer technology uses fixed distances between coils for research, to prevent fluctuations in the receiving voltage, and lead to reduce transmission efficiency. This paper proposes a closed-loop control wireless communication wireless power transfer system with a wearable four-coil structure to stabilize the receiving voltage fluctuation caused

A single-pole four-throw (SP4T) RF switch with charge-pump-based controller is designed and implemented in a commercial 130-nm silicon-on-insulator (SOI) CMOS process. An improved body self-biasing technique based on diodes is utilized to simplify the controlling circuitry and improve the linearity. A multistack field-effect-transistor (FET) structure with body floating technique is employed to provide

This paper reports the realization of planar Schottky diodes based on nanorod ZnO thin film. The nanorod ZnO thin film was fabricated by hydrothermal technique on boron doped p-type Si (100) substrate. The Ag//ZnO/Al planar diode operating with voltage bias from –3 to 3 V. The I – V characteristics clearly indicate that the devices have rectifying performance. The thermionic emission theory governs

To improve the full-well capacity and linear dynamic range of CMOS image sensor, a special finger-shaped pinned photodiode (PPD) is designed. In terms of process, the first N-type ion implantation of the PPD N buried layer is extended under the transfer gate, thereby increasing the PPD capacitance. Based on TCAD simulation, the width and spacing of PPD were precisely adjusted. A high full-well capacity

Based on the density functional theory, the energy band and electronic structure of β -CuGaO 2 are calculated by the modified Becke-Johnson plus an on-site Coulomb U (MBJ + U ) approach in this paper. The calculated results show that the band gap value of β -CuGaO 2 obtained by the MBJ + U approach is close to the experimental value. The calculated results of electronic structure indicate that the

When preparing large monocrystalline silicon materials, severe carbon etching and silicide deposition often occur to the thermal system. Therefore, a suppression method that optimizes the upper insulation structure has been proposed. Assisted by the finite element method, we calculated temperature distribution and carbon deposition of heater and heat shield, made the rule of silicide and temperature

A novel 600 V snapback-free high-speed silicon-on-insulator lateral insulated gate bipolar transistor is proposed and investigated by simulation. The proposed device features an embedded NPN structure at the anode side, and double trenches together with an N-type carrier storage (N-CS) layer at the cathode side, named DT-NPN LIGBT. The NPN structure not only acts as an electron barrier to eliminate

In this work, forward current voltage characteristics for multi-quantum wells Al 0.33 Ga 0.67 As Schottky diode were measured at temperature ranges from 100 to 300 K. The main parameters of this Schottky diode, such as the ideality factor, barrier height, series resistance and saturation current, have been extracted using both analytical and heuristics methods. Differential evolution (DE), particle

Organic zinc-ion batteries (OZIBs) are emerging rechargeable energy storage devices and have attracted increasing attention as one of the promising alternatives of lithium-ion batteries, benefiting from the Zn metal (low cost, safety and small ionic size) and organic electrodes (flexibility, green and designable molecular structure). Organic electrodes have exhibited fine electrochemical performance

Hydrogen can be sustainably produced through photoelectrochemical (PEC) water splitting. The process of PEC water splitting is composed of two vital half-reactions: water oxidation to O 2 on photoanode, and proton reduction to H 2 on photocathode. Both in thermodynamics and kinetics, the oxidation of water on photoanode is much more challenging, because the formation of O 2 involves the four-holes

Photocatalytic hydrogen evolution is one of the most promising ways to solve environmental problems and produce a sustainable energy source. To date, different types of photocatalysts have been developed and widely used in photocatalytic hydrogen evolution. Recently, multinary copper chalcogenides have attracted much attention and exhibited potential applications in photocatalytic hydrogen evolution

Solar water splitting is a promising strategy for the sustainable production of renewable hydrogen and solving the world’s crisis of energy and environment. The third-generation direct bandgap semiconductor of zinc oxide (ZnO) with properties of environmental friendliness and high efficiency for various photocatalytic reactions, is a suitable material for photoanodes because of its appropriate band

Metal-organic frameworks (MOFs) with orderly porous structure, large surface area, high electrochemical response and chemical tunability have been widely studied for energy conversion and storage. However, most reported MOFs still suffer from poor stability, insufficient conductivity, and low utilization of active sites. One strategy to circumvent these issues is to optimize MOFs via designing composites

As a promising photocatalysis material, TiO 2 has long been studied by experimental and theoretical methods. The external strain could affect the catalytic reactivity of TiO 2 significantly due to the difference in surface elastic properties of different surface structures with different surface adsorption or defects. This article reviews our recent work by using density function theory calculations

The exploitation of renewable energy as well as the elimination of the harmful impact of excessive carbon emission are worldwide concerns for sustainable development of the ecological environment on earth. To address that, the technologies regarding energy conversion systems, such as water splitting and electroreduction of carbon dioxide, have attracted significant attention for a few decades. Yet

Lithium–sulfur (Li–S) battery with a new configuration is demonstrated by inserting a flexible nitrogen-doping carbon nanofiber (N-CNFs) interlayer between the sulfur cathode and the separator. The N-CNFs film with high surface roughness and surface area is fabricated by electrospinning and a subsequent calcination process. The N-CNFs film interlayer not only effectively traps the shuttling migration

Due to the quantum size effect and other unique photoelectric properties, quantum dots (QDs) have attracted tremendous interest in nanoscience, leading a lot of milestone works. Meantime, the scope and scientific connotation of QDs are constantly expanding, which demonstrated amazing development vitality. Besides the well-developed Cd-containing II–VI semiconductors, QDs of environmentally friendly

As an emerging organic semiconductor, perylene diimide (PDI) self-assembly has attracted tremendous attention in the aspects of solar cells, sensors, fluorescence probes and n-transistors, etc. In term of photocatalysis, various photocatalysts based on PDI self-assembly exhibit some unique properties, such as intrinsic Π-Π stacking structure, fast internal charge transfer, band-like electronic structure

Black phosphorous (BP), an excellent two-dimensional (2D) monoelemental layered p-type semiconductor material with high carrier mobility and thickness-dependent tunable direct bandgap structure, has been widely applied in various devices. As the essential building blocks for modern electronic and optoelectronic devices, high quality PN junctions based on semiconductors have attracted widespread attention

Precise spatial control of 2D materials is the key capability of engineering their optical, electronic, and mechanical properties. However, growth of novel 2D Mo 2 C on Cu surface by chemical vapor deposition method was revealed to be seed-induced 2D growth, limiting further synthesis of complex Mo 2 C spatial structures. In this research, we demonstrate the controlled growth of Mo 2 C pyramids with

A large number of two-dimensional (2D) monoelemental materials with huge application potentials have been developed, since graphene was reported as a monoelemental material with unique properties. As cousins of graphene, 2D group-V elemental monolayers have gained tremendous interest due to their electronic properties with significant fundamental bandgap. In this review, we extensively summarize the

Due to the quantum confinement effect, atomically thin two-dimensional (2D) monolayer materials possess distinct characteristics from their corresponding bulk materials, which have received wide attention from science and industry. Among all the 2D materials, elemental 2D materials with the simplest components are most striking. As an emerging group-VIA elemental 2D monolayer material, tellurene exhibits

Two-dimensional (2D) bismuth, bismuthene, is an emerging pnictogen family member that has received increasing research attention in the past few years, which could yield exotic electrical, thermal, and optical properties due to unique band structure. This review provides a holistic view of recent research advances on 2D bismuth material synthesis and device applications in complementary metal oxide