Browsing by Author "Huang, Chun-Yao"

Now showing 1 - 4 of 4

Investigation of source-follower type analog buffer using low temperature poly-Si TFTs
(2007-03-01)
Chen, Bo-Ting
;
Tai, Ya-Hsiang
;
Wei, Ying-Jyun
;
Wei, Kai-Fang
;
Tsai, Chun-Chien
A new source follower circuit using low-temperature polycrystalline silicon thin film transistors (LTPS-TFTs) as analog buffer for the integrated data driver circuit of active matrix liquid crystal displays (AMLCDs) and active matrix light emitting diodes (AMOLEDs) is proposed and measured. Threshold voltage compensation circuit with two n-type thin film transistors, a capacitor, and four switches structure is used to enhance image quality for the display. The threshold voltage difference of driving TFTs and the unsaturated of output voltage are eliminated in this circuit. An active load is added and a calibration operation is applied to study the effects on the source follower circuit, the transistor operation mode region is also discussed. The proposed circuit is capable of minimizing the variation from both the signal timing and the device characteristics through the simulation and measured results. (C) 2007 Elsevier Ltd. All rights reserved.
On-panel analog output buffer for data driver with consideration of device characteristic variation in LTPS technology
(2007)
Li, Yu-Hsuan
;
Ker, Ming-Dou
;
Huang, Chun-Yao
;
Hsu, Chun-Yuan
;
電機學院
A class-A analog output buffer for the data driver with consideration of device variation in low temperature poly-silicon (LTPS) technology is proposed. With high enough mobility, LTPS thin-film transistor (TFT) has been suitable for the realization with driver circuits on the LCD panel to meet system-on-panel (SoP) applications. However, the device characteristics of poly-Si TFTs have poor uniformity and suffer from huge variations in different locations due to the poly-silicon grain structures. Besides, the variation on device characteristic of the N-type TFT is much worse than that of P-type TFT. Therefore, replacing the critical part of the analog circuit by P-TFTs is a good design solution for suppressing device characteristic variation in order to improve manufacturing yield of the analog circuit on panel. A class-A output buffer realized with P-TFTs as the input stage has been designed and fabricated in a 8-mu m LTPS technology. From the experimental results, this proposed analog output buffer with P-TFTs as input stage can be operated at 50-kHz operation frequency with at least a 1-to-9 V output swing for using in the on-panel data drivers to provide a uniform brightness and high resolution display.
Source-Follower Type Analog Buffer Using Low Temperature Poly-Si TFTs for AMLCDs
(2006)
Chen, Bo-Ting
;
Tai, Ya-Hsiang
;
Wei, Ying-Jyun
;
Tsai, Chun-Chien
;
Chen, Hsu-Hsin
A new source follower circuit for the integrated circuit of AMLCDs is proposed. Active load is added and calibration operation is applied to compensate the circuits. Proposed circuit is capable of minimizing variation from both timing and device variations through measured results, the uniformity and bias effect are discussed.
Threshold-voltage-compensation methods for AMOLED pixel and analog buffer circuits
(2006-09-01)
Chen, Bo-Ting
;
Tai, Ya-Hsiang
;
Wei, Ying-Jyun
;
Tsai, Chun-Chien
;
Huang, Chun-Yao
New pixel-circuit designs for active-matrix organic light-emitting diodes (AMOLEDs) and a new analog buffer circuit for the integrated data-driver circuit of active-matrix liquid-crystal displays (AMLCDs) and AMOLEDs, based on low-temperature polycrystalline-silicon thin-film transistors (LTPS-TFTs), were proposed and verified by SPICE simulation and measured results. Threshold-voltage-compensation pixel circuits consisting of LTPS-TFTs, an additional control signal line, and a storage capacitor were used to enhance display-image uniformity. A diode-connected concept is used to calibrate the threshold-voltage variation of the driving TFT in an AMOLED pixel circuit. An active load is added and a calibration operation is applied to study the influences on the analog buffer circuit. The proposed circuits are shown to be capable of minimizing the variation from the device characteristics through the simulation and measured results.