Browsing by Author "Liu, HC"

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A 15-b 40-MS/s CMOS pipelined analog-to-digital converter with digital background calibration
(2005-05-01)
Liu, HC
;
Lee, ZM
;
Wu, JT
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This study presents a 15-b 40-MS/s switched-capacitor CMOS pipelined analog-to-digital converter (ADC). High resolution is achieved by using a correlation-based background calibration technique that can continuously monitor the transfer characteristics of the critical pipeline stages and correct the digital output codes accordingly. The calibration can correct errors associated with capacitor mismatches and finite opamp gains. The ADC was fabricated using a 0.25-mu m 1P5M CMOS technology. Operating at a 40-MS/s sampling rate, the ADC attains a maximum signal-to-noise-plus-distortion ratio of 73.5 dB and a maximum spurious-free-dynamic-range of 93.3 dB. The chip occupies an area of 3.8 x 3.6 mm(2), and the power consumption is 370 mW with a single 2.5-V supply.
A 15-bit 40-MS/s CMOS pipelined analog-to-digital converter with digital background calibration (vol 40, pg 1047, 2005)
(2005-11-01)
Liu, HC
;
Lee, ZM
;
Wu, JT
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A 15b 20MS/s CMOS pipelined ADC with digital background calibration
(2004)
Liu, HC
;
Lee, ZM
;
Wu, JT
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交大名義發表
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National Chiao Tung University
Antioxidant role of human haptoglobin
(2004-08-01)
Tseng, CF
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Lin, CC
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Huang, HY
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Liu, HC
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Mao, SJT
Human plasma haptoglobin (Hp) is classified according to three phenotypes: Hp 1-1, 2-1, and 2-2 attributed by their two common alleles 1 and 2. Clinically, the 2-2 phenotype is associated with the risk of cardiovascular diseases and diabetes mellitus in patients. In this study, we demonstrate that Hp is an extremely potent antioxidant, which directly protects low density lipoprotein from Cu2+-induced oxidation. Its potency was markedly superior to probucol (one of the most potent antioxidants). Ranking of the IC50 of antioxidant activity was as follows: Hp 1-1 > Hp 2-1 > Hp 2-2 > probucol > vitamin E. Blockage of disulfide linkages between Hp subunits, not only abolished the alpha-helical content but also diminished the ability of Hp to form a complex with hemoglobin. The modified Hp subunits exerted almost 4 times greater antioxidant activity than that of native Hp. To investigate the antioxidant role of Hp on the cellular level, the cDNA of Hp 1-1 was cloned, introduced into the pcDNA3.0 vector which contains the cytomega lovirus promoter and transfected into chinese hamster ovary (CHO)-K1 cells. Following transfection, CHO cells were able to express Hp 1-1 protein and significantly (p < 0.001) elevated cell tolerance against oxidative stress. Transfected cells showed 2-fold higher resistance to hydrogen peroxide exposure for 24 h compared to control cells. Thus, Hp plays a provocative antioxidant role as demonstrated by our in vitro and ex vivo studies.
beta-Lactoglobulin is a sensitive thermal maker in dry milk as identified by monoclonal antibody approach
(2003-03-17)
Chen, WL
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Huang, MT
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Liu, HC
;
Li, CW
;
Mao, SJT
Digital background calibration technique for pipelined analog-to-digital converters
(2003)
Liu, HC
;
Lee, ZM
;
Wu, JT
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A new background calibration technique for pipelined analog-to-digital converters is proposed. By dividing the step sizes of the multiplying digital-to-analog converter (MDAC) in a pipeline stages and injecting a random signal into the MDAC, it is possible to calibrate a pipeline stage without interrupting the normal analog-to-digital operation. The calibration can eliminate the nonlinear effects due to the MDAC's gain error, input offset voltage, and output errors in the digital-to-analog conversion.
Distinction between dry and raw milk using monoclonal antibodies prepared against dry milk proteins
(2004-08-01)
Chen, WL
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Huang, MT
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Liu, HC
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Li, CW
;
Mao, SJT
It is well established that the heating process during the preparation of dry milk (DMLK) causes structural changes in some milk proteins. However, because such changes are subtle, whether they can be detected by an immunochemical approach remains questionable. The present study attempted to develop a sensitive mAb that might distinguish the DMLK from freshly prepared raw milk. To test this possibility, we immunized mice with commercially prepared DMLK and produced a panel of mAb. From 900 hybridomas screened using an ELISA, 4 clones were found to be specific to DMLK; the other 68 clones recognized both DMLK and raw milk. In contrast to polyclonal antibodies, only the specific mAb could detect the DMLK spiked into the raw milk at as low as 5% in concentration (vol/vol). Western blot analysis shows that these specific mAb were all directed against beta-lactoglobulin (LG) and LG-milk protein conjugates. These mAb reacted with raw milk heated at 95 for 15 min; the reaction with LG-conjugates, however, was abolished when treated with reducing reagent. Thus, results suggests that a new antigenic epitope was exposed in a heating process, and the thio group of LG cross linked with other protein moiety played a provocative role in mAb recognition. A hypothetical model with respect to the interaction between the mAb and DMLK is proposed and discussed.
Enhanced performance of poly-Si thin film transistors using fluorine ions implantation
(2005)
Tu, CH
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Chang, TC
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Liu, PT
;
Zan, HW
;
Tai, YH
Fluorine (F)-implanted polycrystalline silicon thin-film transistor (poly-Si TFT) are proposed for the enhancement of device performance. A significant improvement in electrical characteristics, such as I-ON/I-OFF ratio, and field effect mobility, can be realized in the new thin-film transistor. The field effect mobility for F-implanted poly-Si TFTs is 53.82 cm(2)/V-s, and higher than 19.74 cm(2)/V-s in conventional SPC poly-Si TFTs. Furthermore, the F-implanted poly- Si TFT exhibits high immunity against hot carrier effect and improved electrical reliability. The manufacturing processes are simple and without additional thermal annealing steps, thereby compatible with the conventional TFT fabrication processes. (c) 2005 The Electrochemical Society. All rights reserved.
Fast direct solver for the biharmonic equation on a disk and its application to incompressible flows
(2005-05-25)
Lai, MC
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Liu, HC
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應用數學系
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Department of Applied Mathematics
We develop a simple and efficient FFT-based fast direct solver for the biharmonic equation on a disk. The biharmonic equation is split into a coupled system of harmonic problems. We first use the truncated Fourier series expansion to derive a set of coupled singular ODEs, then we solve those singular equations by second-order finite difference discretizations. Using a radial grid with shifting a half mesh away from the origin, we can handle the coordinate singularity easily without pole conditions. The Sherman-Morrison formula is then applied to solve the resultant linear system in a cost-efficient way. The computational complexity of the method consists of O(MN log(2) N) arithmetic operations for M x N grid points. The numerical accuracy check and some applications to the incompressible Navier-Stokes flows inside a disk are conducted. (c) 2004 Elsevier Inc. All rights reserved.
Formation of silicon germanium nitride layer with distributed charge storage elements
(2006-03-13)
Tu, CH
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Chang, TC
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Liu, PT
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Liu, HC
;
Chen, WR
The formation of silicon germanium nitride (SiGeN) with distributed charge storage elements is proposed in this work. A large memory window is observed due to the retainable dangling bonds inside the SiGeN gate stack layer. The nonvolatile memory device with the high-temperature oxidized SiGeN stack layer exhibits 2 V threshold voltage shift under 7 V write operation, which is sufficient for a memory device to define the signal "0" and "1." Also, the manufacture technology using the sequent high-temperature oxidation of the a-Si layer acting as the blocking oxide is proposed to enhance the performance of nonvolatile memory devices. (c) 2006 American Institute of Physics.
Improvement of electrical characteristics for fluorine-ion-implanted poly-Si TFTs using ELC
(2006-04-01)
Tu, CH
;
Chang, TC
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Liu, PT
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Yang, CY
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Liu, HC
The fluorine ion implantation applied to the polycrystalline silicon thin-film transistors (poly-Si TFTs) is investigated in this letter. Experimental results have shown that fluorine ion implantation effectively minimized the trap state density, leading to superior electrical characteristics such as high field-effect mobility, low threshold voltage, and high ON/OFF current ratio. Furthermore, the fluorine ions tended to segregate at the interface between the gate oxide and poly-Si layers during the excimer laser annealing, even without the extra deposition of pad oxide on the poly-Si film. The presence of fluorine obviously enhanced electrical reliability of poly-Si TFTs.
Parameters study to improve sidewall roughness in Advanced Silicon Etch process
(2001)
Liu, HC
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Lin, YH
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Chou, BCS
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Hsu, YY
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Hsu, WS
In ICP-RIE process, there have been many investigations on etching rate. However, only few published reports mentioned the sidewall roughness, which is a critical issue for optical devices. Here, experimental investigations about fabrication parameters in the STS Advanced Silicon Etch (ASE) process for sidewall roughness are performed. In our experiments, the photoresist of AZ1500 is used, and several parameters in the ASE process like over time, ramping time, Ar flow rate, platen power, and etching cycle time have been systematically studied. It is found that sidewall mean roughness can be down to 9.11 nm at etching rate of 2.5 mum/min. Comparing with other published works at similar sidewall roughness (around 10 nm), our experimental data have the highest etching rate. For the same STS ICP-RIE systems, our data have smallest sidewall roughness, comparing to previous literatures.
Sidewall roughness control in advanced silicon etch process
(2003-12-01)
Liu, HC
;
Lin, YH
;
Hsu, W
;
機械工程學系
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Department of Mechanical Engineering
In ICP-RIE process, there have been many investigations on etching rate. However, only few published reports mentioned the sidewall roughness, which is a critical issue for optical devices. Here, experimental investigations about fabrication parameters in the STS advanced silicon etch (ASE) process for sidewall roughness are performed. In our experiments, several parameters in the ASE process like over time, ramping time, Ar flow rate, platen power, and etching cycle time have been systematically studied. It is found that sidewall mean roughness can be down to 9.11 nm at etching rate of 2.5 mum/min. Comparing with other published works at similar sidewall roughness (around 10 nm), our experimental data have the highest silicon etching rate. For the same STS ICP-RIE systems, our data have smallest sidewall roughness, comparing to previous data published in the litherature.
Thermal denaturation of beta-lactoglobulin as probed by an monoclomal antibody
(2004-03-23)
Chen, WL
;
Huang, MT
;
Li, CW
;
Liu, HC
;
Mao, SJT