• ETRI Journal
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• 제34권4호
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• pp.633-636
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• 2012

A dynamic analysis of an amorphous silicon (a-Si) thin film transistor liquid crystal display (TFT-LCD) pixel is presented using new a-Si TFT and liquid crystal (LC) capacitance models for a Simulation Program with Integrated Circuit Emphasis (SPICE) simulator. This dynamic analysis will be useful when predicting the performance of LCDs. The a-Si TFT model is developed to accurately estimate a-Si TFT characteristics of a bias-dependent gate to source and gate to drain capacitance. Moreover, the LC capacitance model is developed using a simplified diode circuit model. It is possible to accurately predict TFT-LCD characteristics such as flicker phenomena when implementing the proposed simulation model.

• 대한전자공학회논문지SD
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• 제38권12호
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• pp.25-35
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• 2001

복잡한 thin film transistor-liquid crystal display (TFT-LCD) array 회로의 전기적 특성을 분석하기 위해서는 PSPICE나 AIM-SPICE와 같은 회로 시뮬레이터를 사용하는 것이 필수적이다. 본 논문에서는 SPICE 시뮬레이션을 위한 다결정 실리콘 (poly-Si) TFT 소자의 입력 변수 추출을 체계화하는 방법을 도입한다. 이 방법을 excimer laser annealing 및 silicide mediated crystallization 방법으로 각각 제작된 다결정 실리콘 TFT 소자에 적용하여 실험 결과와 잘 일치하는 결과를 얻었다. SPICE 시뮬레이터 중에서 PSPICE는 graphic user interface(GUI) 방식의 편의성을 제공하므로 손쉽게 복잡한 회로를 구성할 수가 있다는 장점이 있으나, poly-Si TFT 소자 모델을 가지고 있지 않다. 이 연구에서는 PSPICE에 다결정 실리콘 TFT 소자 모델을 이식하고, TFT가 이식된 PSPICE를 사용하여 poly-Si TFT-LCD 단위 화소 및 라인 RC 지연을 고려한 화소에 대한 전기적 특성을 분석하였다. 이러한 결과는 TFT-LCD 어레이 특성 분석을 위한 시뮬레이션을 효율적으로 수행하는데 기여할 수 있을 것으로 기대된다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.314-317
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• 2000

In order to analyze the characteristics of complicated TFT-LCD (Thin Film Transistor-Liquid Crystal Display) circuits, it is indispensible to use simulation programs. In this study, we present a systematic method of extracting the input parameters of poly-Si TFT for Spice simulation. This method is applied to two different types of poly-Si TFTs fabricated in our group with good results. Among the Spice simulators, Pspice has the graphic user interface feature making the composition of complicated circuits easier. We added successfully a poly-Si TFT model on the Pspice simulator, which would contribute to efficient simulations of poly-Si TFT-LCD pixels and arrays.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.320-323
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• 2000

In the resent years, the Thin Film Transistor Liquid Crystal Display(TFT-LCD) have trend toward larger panel sizes and higher spatial and/or gray-scale resolution. In this trend, Because of its low field effect mobility, a-Si TFT is change to poly-Si TFT. In this paper, both effective-medium model of poly-Si TFTs and empirical capacitance model are applied to Pixel Design Array Simulation Tool (PDAST) and the pixel characteristics of TFT-LCD array were simulated, which were compared with the results calculated by Aim-Spice.

• 전기학회논문지P
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• 제62권2호
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• pp.84-89
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• 2013

In this paper, we propose interface circuits for reducing power consumption and EMI when sequences of data from LCD controller to LCD driver IC by transmitting two bit data during one clock period. The proposed circuits are operated in current mode, which is different from conventional voltage-mode signaling techniques, and also employ threshold technique of Modified-LVDS(Low Voltage Differential Signaling) method. We have simulated the proposed circuits using H-SPICE tool for performance analysis of the proposed method. The simulation results show that the proposed circuits provide a faster transmission speed and stronger noise immunity than the conventional LVDS circuits. It might be suitable for the real-time transmission of huge image data in LCD system.

• 한국전기전자재료학회논문지
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• 제20권3호
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• pp.250-256
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• 2007

We analyzed the effect of a pixel and all the inter-electrode capacitances in a unit pixel of TFT-LCDs on the gray scale capability. The pixel and all the inter-electrode parasitic capacitances were obtained from the tree dimensional profiles of potential distribution and molecular director considering lateral fields generated at the edge of the pixel. To obtain the RMS and kickback voltages of the pixel, we constructed an equivalent circuit of the panel containing all the parasitic capacitances. The calculation was performed though H-SPICE. As results, we confirmed that the pixel becomes smaller, the effect of parasitic capacitances on the gray scale capability becomes larger.

• 한국전기전자재료학회논문지
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• 제21권4호
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• pp.368-375
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• 2008

In this paper, we calculated the pixel and all the inter-electrode capacitances in a unit pixel of three kinds of TFT-LCD modes in order to realize the full color image. And we analyzed the effect on applied voltage. We fixed size of sub-pixel and designed a unit pixel of three kinds of TFT-LCD modes. We calculated rigorously the pixel and all the inter-electrode capacitances by the three dimensional simulation. And we expanded one pixel into whole panel using H-SPICE. As a result, we calculated the RMS voltage and kickback voltage which most affect gray scale of the pixel and calculated the number of bit according to permissible range of minimum gray scale using V-T curve.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.898-901
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• 2005

We propose a novel pixel structure using bootstrapped voltage programming for amorphoussilicon TFT backplane of AM-OLED (Active Matrix-Organic Light Emitting Diode) displays. The proposed structure is composed of two TFTs and one capacitor. It operates at low drive voltage ($0{\sim}5V$) which can reduce power consumption comparing with the conventional pixel circuit structure using same OLED material. Also, it can easily control dark level and use commercial mobile LCD ICs. In this paper, we describe the operating principle and the characteristics of the proposed pixel structure and verify the performance by SPICE simulation comparing with the conventional pixel structure.