A nanoresonator can be applied as a biochemical sensor based on the change in the mass of the nanoresonator, and the mass change can be interpreted in the frequency domain. In this paper, we present ...an open-loop spectrum analyzer integrated circuit (IC) for a nanoresonator. The circuit determines the frequency characteristics of a nanoresonator, such as quality factor (Q-factor) and resonant frequency, and detects minute resistance changes of the nanoresonator that result in changes in Q-factor or resonant frequency. The proposed nanoresonator driver circuit is implemented using an open-loop system, and to characterize the open-loop frequency response of the nanoresonator, the IC includes a voltage-controlled oscillator, a transimpedance amplifier, and a 16-bit delta-sigma analog-to-digital converter. To compensate for the parasitic components that cause the distortions of the phase and magnitude response, a shunt-capacitance cancelling amplifier is used to cancel the effect of the shunt-parasitic capacitance of the nanoresonator. The simulated target nanoresonator is modeled using the Butterworth–Van Dyke equivalent circuit model with a resonant frequency of 10 MHz. The proposed nanoresonator driver circuit is fabricated using a standard 0.18 μm complementary metal oxide semiconductor process with an active area of 2.346 mm2. The simulated resistive sensitivity of the IC is 5.1 mV/kΩ.
OPC UA 기반 스마트팩토리 디지털 트윈 테스트베드 시스템 개발 김재성(Jaesung Kim); 정석찬(Seok Chan Jeong); 서동우(Dongwoo Seo) ...
멀티미디어학회논문지,
2022, Letnik:
25, Številka:
8
Journal Article
Recenzirano
Odprti dostop
The manufacturing industry is continuously pursuing advanced technology and smartization as it converges with innovative technology. Improvement of manufacturing productivity is achieved by ...monitoring, analyzing, and controlling the facilities and processes of the manufacturing site in real time through a network. In this paper, we proposed a new OPC-UA based digital twin model for smart factory facilities. A testbed system for USB flash drive packaging facility was implemented based on the proposed digital twin model and OPC-UA data communication scheme. Through OPC-UA based digital twin model, equipment and process status information is transmitted and received from PLC to monitoring and control 3D digital models and physical models in real time. The usefulness of the developed digital twin testbed system was evaluated through usability test.
Until now, thermally activated delayed fluorescence (TADF) materials based on bridged boron-based acceptors have been primarily developed as dopants. However, in this study, we synthesized and ...characterized multifunctional deep-blue TADF materialst-OBO-DMAC and t-OBO-DPACusing bridged boron-based acceptors in combination with dimethylacridine or diphenylacridine as donors. These materials serve as both dopants and hosts. Theoretical calculations and experimentally measured photophysical properties of t-OBO-DMAC reveal a smaller singlet–triplet energy difference, higher photoluminescence quantum yield, and more efficient reverse intersystem crossing compared to t-OBO-DPAC. When evaluated as TADF emitters, t-OBO-DMAC and t-OBO-DPAC exhibited maximum external quantum efficiency (EQE) of 14.4 and 7.3% with deep-blue color coordinates of (0.14, 0.11) and (0.15, 0.07), respectively. Both materials were further assessed as hosts in various configurations, including host-only, TADF, phosphorescent, and phosphor-sensitized fluorescence (PSF)-emitting systems. Notably, t-OBO-DMAC demonstrated a high maximum EQE of 13.9% with deep-blue color coordinates of (0.15, 0.07) in a nondoped host-only device. Remarkably, both materials achieved EQEs exceeding 20% in the PSF devices. Our study marks a critical advancement in the field that breaks the conventional boundaries of the dopant and host and demonstrates unprecedented multifunctionalities for advanced organic light-emitting diodes.
This paper proposes a low noise readout integrated circuit (IC) with a chopper-stabilized multipath operational amplifier suitable for a Wheatstone bridge sensor. The input voltage of the readout IC ...changes due to a change in input resistance, and is efficiently amplified using a three-operational amplifier instrumentation amplifier (IA) structure with high input impedance and adjustable gain. Furthermore, a chopper-stabilized multipath structure is applied to the operational amplifier, and a ripple reduction loop (RRL) in the low frequency path (LFP) is employed to attenuate the ripple generated by the chopper stabilization technique. A 12-bit successive approximation register (SAR) analog-to-digital converter (ADC) is employed to convert the output voltage of the three-operational amplifier IA into digital code. The Wheatstone bridge readout IC is manufactured using a standard 0.18 µm complementary metal-oxide-semiconductor (CMOS) technology, drawing 833 µA current from a 1.8 V supply. The input range and the input referred noise are ±20 mV and 24.88 nV/√Hz, respectively.
This paper proposes a reconfigurable sensor analog front-end using low-noise chopper-stabilized delta-sigma capacitance-to-digital converter (CDC) for capacitive microsensors. The proposed ...reconfigurable sensor analog front-end can drive both capacitive microsensors and voltage signals by direct conversion without a front-end amplifier. The reconfigurable scheme of the front-end can be implemented in various multi-mode applications, where it is equipped with a fully integrated temperature sensor. A chopper stabilization technique is implemented here to achieve a low-noise characteristic by reducing unexpected low-frequency noises such as offsets and flicker noise. The prototype chip of the proposed sensor analog front-end is fabricated by a standard 0.18-μm 1-poly-6-metal (1P6M) complementary metal-oxide-semiconductor (CMOS) process. It occupies a total active area of 5.37 mm² and achieves an effective resolution of 16.3-bit. The total power consumption is 0.843 mW with a 1.8 V power supply.
A low-noise analog front-end (AFE) with chopper-stabilized multipath current-feedback instrumentation amplifier (CFIA) for resistive sensors is proposed. Low-noise techniques are essential for the ...operation of precise resistive sensors, and chopper stabilization techniques have been commonly implemented in previous studies. However, techniques that are only based on chopper stabilization suffer from the disadvantage of a low bandwidth. To address this problem, a multipath operational amplifier is implemented in this work. Also, the chopper stabilization technique is implemented in the low-frequency path of a multipath operational amplifier. This chopper stabilization technique causes the "ripple" generated by the offset voltage. A ripple rejection loop in the low-frequency path is utilized to remove this ripple. In addition, a successive approximation register (SAR) analog-to-digital converter (ADC) is used to convert the measured analog signal into a digital output. The converter has an effective number of bits (ENOBs) of 11.02 and a signal-to-noise and distortion ratio (SNDR) of 75.68 dB. The resistive AFE with SAR ADC is designed using a 0.18 μm complementary metal-oxide-semiconductor (CMOS) process with an active area of 8.6 mm2. It operates at 2.56 mW with a 1.8 V supply and has an input-referred noise of 0.29 μVrms in the range of 1 to 100 Hz.
This paper presents a low-noise multi-path operational amplifier for high-precision sensors. A chopper stabilization technique is applied to the amplifier to remove offset and flicker noise. A ripple ...reduction loop (RRL) is designed to remove the ripple generated in the process of up-modulating the flicker noise and offset. To cancel the notch in the overall transfer function due to the RRL operation, a multi-path architecture using both a low-frequency path (LFP) and high-frequency path (HFP) is implemented. The low frequency path amplifier is implemented using the chopper technique and the RRL. In the high-frequency path amplifier, a class-AB output stage is implemented to improve the power efficiency. The transfer functions of the LFP and HFP induce a first-order frequency response in the system through nested Miller compensation. The low-noise multi-path amplifier was fabricated using a 0.18 µm 1P6M complementary metal-oxide-semiconductor (CMOS) process. The power consumption of the proposed low-noise operational amplifier is 0.174 mW with a 1.8 V supply and an active area of 1.18 mm2. The proposed low-noise amplifier has a unit gain bandwidth (UGBW) of 3.16 MHz, an input referred noise of 11.8 nV/√Hz, and a noise efficiency factor (NEF) of 4.46.
Deep desulfurization properties and characteristics of activated carbon (AC) modified by impregnation of CuCl
2
were studied using simulated hydrocarbon fuels containing dimethyl sulfide (DMS),
tert
...-butylmercaptan (TBM), and tetrahydrothiophene (THT), the typical organosulfur compounds representing sulfides, thiols, and thiophenes that exist in fuel gases. The pristine AC had limited adsorptive desulfurization performance for a ternary DMS-THT-TBM mixture feed with an early breakthrough of DMS and TBM due to its preferential adsorption of THT. The adsorption of these organosulfur species on the AC surface was intrinsically weak and competing, as indicated by their low desorption activation energies (37-39 kJ mol
−1
). However, relatively stronger adsorption of THT than the others led to the AC surface gradually being covered by THT through replacement of the initially adsorbed TBM and DMS. The impregnation of CuCl
2
on the AC (3.4 atomic % Cu) additionally formed strong and selective adsorption sites for TBM (activation energy=58.6 kJ mol
−1
) on the AC surface, which gave rise to about three-fold increase in the total breakthrough adsorption capacity for these sulfur species. The structure and physicochemical properties of the adsorbents were characterized by N
2
adsorption, x-ray diffraction, x-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and surface pH measurement. The results suggested that the modulation of adsorption selectivity of the AC surface by CuCl
2
impregnation had significant effects on the overall deep desulfurization performance for fuel gases containing multiple organosulfur species in practical conditions.
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