• Title/Summary/Keyword: bias current

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Linear cascode current-mode integrator (선형 캐스코드 전류모드 적분기)

  • Kim, Byoung-Wook;Kim, Dae-Ik
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.10
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    • pp.1477-1483
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    • 2013
  • This paper proposes a low-voltage current-mode integrator for a continuous-time current-mode baseband channel selection filter. The low-voltage current-mode linear cascode integrator is introduced to offer advantages of high current gain and improved unity-gain frequency. The proposed current-mode integrator has fully differential input and output structure consisting of CMOS complementary circuit. Additional cascode transistors which are operated in linear region are inserted for bias to achieve the low-voltage feature. Frequency range is also controllable by selecting proper bias voltage. From simulation results, it can be noticed that the implemented integrator achieves design specification such as low-voltage operation, current gain, and unity gain frequency.

a-Si:H Photodiode Using Alumina Thin Film Barrier

  • Hur Chang-Wu;Dimitrijev Sima
    • Journal of information and communication convergence engineering
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    • v.3 no.4
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    • pp.179-183
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    • 2005
  • A photodiode capable of obtaining a sufficient photo/ dark current ratio at both forward bias state and reverse bias state is proposed. The photodiode includes a glass substrate, an aluminum film formed as a lower electrode over the glass substrate, an alumina film formed as an insulator barrier over the aluminum film, a hydrogenated amorphous silicon film formed as a photo conduction layer over a portion of the alumina film, and a transparent conduction film formed as an upper electrode over the hydro-generated amorphous silicon film. A good quality alumina $(Al_2O_3)$ film is formed by oxidation of aluminum film using electrolyte solution of succinic acid. Alumina is used as a potential barrier between amorphous silicon and aluminum. It controls dark-current restriction. In case of photodiodes made by changing the formation condition of alumina, we can obtain a stable dark current $(\~10^{-12}A)$ in alumina thickness below $1000{\AA}$. At the reverse bias state of the negative voltage in ITO (Indium Tin Oxide), the photo current has substantially constant value of $5{\times}10^{-9}$ A at light scan of 100 1x. On the other hand, the photo/dark current ratios become higher at smaller thicknesses of the alumina film. Therefore, the alumina film is used as a thin insulator barrier, which is distinct from the conventional concept of forming the insulator barrier layer near the transparent conduction film. Also, the structure with the insulator thin barrier layer formed near the lower electrode, opposed to the ITO film, solves the interface problem of the ITO film because it provides an improved photo current/dark current ratio.

Optimum design on the commutation circuit of a current source inverter feeding on induction motor (유도전동기 구동을 위한 전류형 인버어터의 전류회로 최적설계에 관한 연구)

  • 노창주;홍순일
    • Journal of Advanced Marine Engineering and Technology
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    • v.9 no.3
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    • pp.250-256
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    • 1985
  • With the advant of thryistors having large peak inverse voltages, current-source inverters are becoming very popular to feed induction motors. But it is very difficult to analysis the commutation. Since the actual variation of current during commutation is neither instantaneous nor linear and is effected by many parameters. Minimized bias-time of reverse voltages during commutation is expressed in term of machine parameters, capacitor voltage, load current and so on. The minimized bias-time is computed with y and z and also the commuation mechanism is tested on 2.2 kw induction motor. The computed results are compared with the experimental results, and the results give a good information for designing the commutation mechanism.

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DESIGN OF THE RLG CURRENT STABILIZER CIRCUIT FOR ATTITUDE CONTROL IN THE SATELLITE (위성 자세제어용 RLG 전류 안정화 회로 설계)

  • Kim Eui-Chan;Choi Jae-Dong
    • Journal of Astronomy and Space Sciences
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    • v.23 no.2
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    • pp.161-166
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    • 2006
  • In this paper, we describe the RLG current stabilizer circuit for attitude control in the satellite. The RLG makes use of the Sagnac effect within a resonant of a HeNe laser. The difference between two discharge currents causes one of the gyro bias errors. The theoretical background and current stabilizer are introduced. It is verified that the circuit designed is applicable to the test of input voltage and temperature.

High Current Stress characteristics on Sequential Lateral Solidification (SLS) Poly-Si TFT

  • Jung, Kwan-Wook;Kim, Ung-Sik;Kang, Myoung-Ku;Choi, Pil-Mo;Lee, Su-Kyeong;Kim, Hyun-Jae;Kim, Chi-Woo;Jung, Kyu-Ha
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.673-674
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    • 2003
  • The reliability of TFT, crystallized by sequential lateral solidification (SLS) technology, has been studied High current damage is characterized by high gate bias (-20V) and drain bias (-10V). It is found that performance of SLS TFTs is enhanced by high current stress up to 300 sec of stress time for 20/8 (W/L) N-TFT. After that, TFT performance is degraded with the increase of the stress time. It is speculated from the experimental data that SLS TFTs initially contain a number of unstable defect states. Then, the defect states seem to be cured by high current stress.

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A Study on Displacement Current Characteristics of DMPC Monolayer (II) (DMPC 인지질 단분자막의 변위전류 특성 연구 (II))

  • Song, Jin-Won;Lee, Kyung-Sup;Choi, Yong-Sung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.2
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    • pp.343-348
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    • 2007
  • The physical properties of DMPC monolayer were made for dielectric relaxation phenomena by the detection of the surface pressures and displacements current. Lipid thin films were deposited by accumulation and the current was measured after the electric bias across the manufactured MIM device. It is found that the phospolipid monolayer of dielectric relaxation takes a little time and depend on the molecular area. When electric bias is applied across the manufactured MIM device by the deposition condition of phospolipid mono-layer, it wasn't breakdown when the higher electric field to impress by increase of deposition layers.

A Current-controlled CMOS operational transconductance amplifier (전류- 제어 CMOS operational transconductance amplifier)

  • Chung, W.S.;Cha, H.W.;Kim, H.B.;Rho, S.R.
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.563-566
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    • 1988
  • A current-controlled CMOS operational transconductance amplifier(OTA), whose transconductance is directly proportional to the DC bias current, has been developed for many electronic circuit applications. It features that its transconductance is insensitive to temperature unlike that of the bipolar OTA. This property makes it possible to use the proposed OTA as a basic buliding block in electrically variable circuit design. The SPICE simulation shows that the conversion sensitivity of the circuit is 44.62 mv /${\mu}A$ and the linearity error less than 0.54 % over a bias current range from 2 ${\mu}A$ to 120 ${\mu}A$ when the output is loaded with a 1${\Omega}$ resistor.

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Current-voltage Characteristics of Ceramics with Positive Temperature Coefficient of Resistance

  • Li, Yong-Gen;Cho, Sung-Gurl
    • Journal of the Korean Ceramic Society
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    • v.40 no.10
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    • pp.921-924
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    • 2003
  • A current-voltage relation for Positive Temperature Coefficient of Resistance (PTCR) ceramic was derived and compared with the experimental data. The new current-voltage relation was developed based on Heywangs double Schottky barrier model and a bias distribution across the grain boundary. The voltage limitation V < 4${\Phi}$$\sub$b/ suggested by Heywang is no longer necessary in the new expression for the voltage dependence of the resistance. The pulsed voltages were applied to the PTCR ceramic specimen in order to avoid possible temperature variation during the measurement.

Field-domain dynamics and current self-oscillations in negative-effective-mass terahertz oscillators

  • Cao, J.C.;Qi, M.
    • Journal of the Korean Vacuum Society
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    • v.12 no.S1
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    • pp.36-39
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    • 2003
  • Field-domain dynamics and current self-oscillations are theoretically studied in quantum-well (QW) negative-effective-mass (NEM) $p^{+}pp^{+}$ diodes when the electric field is applied along the direction of the well. The origin of current self-oscillations is the formation and traveling of electric-field domains in the p-base. We have accurately considered the scattering contributions from carrier-impurity, carrier-acoustic phonon, and carrier-optic phonon. It's indicated that, both the applied bias and the doping concentration largely influence the current patterns and self-oscillating frequencies, which lie in the THz range for the NEM $p^{+}pp^{+}$ diode with a submicrometer p-base. The complicated field-domain dynamics is presented with the applied bias as the controlling parameter.

A Study on Self-bias SCR Based on LRSCR for Low Voltage Class ESD Protection (저전압급 ESD 보호를 위한 LRSCR 기반 Self-bias SCR에 관한 연구)

  • U-Yeol Seo;Sang-wook Kwon;Jae-yoon Oh;Yong-Seo Koo
    • Journal of IKEEE
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    • v.28 no.2
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    • pp.239-242
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    • 2024
  • This paper proposed an ESD protection device that improved the current driving ability through Self-bias than the existing ESD protection device. The new proposed structure is based on the LRSCR structure and adds an N+ diffusion region, and reduces resistance by connecting the gate and the P+ diffusion region. As a result, it was confirmed that the proposed ESD protection device exhibits a trigger voltage of 11.8V and a holding voltage of 5.9V. It can be used in 5V applications for low voltage and is expected to have excellent current driving capability.