Browsing by Author "Li, Yu-Hsuan"

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Design and Realization of Delta-Sigma Analog-to-Digital Converter in LTPS Technology
(2009)
Tsai, Chia-Chi
;
Ker, Ming-Dou
;
Li, Yu-Hsuan
;
Kuo, Chung-Hung
;
Li, Chun-Huai
A delta-sigma analog-to-digital (A/D) converter designed and implemented with the thin-film transistors (TFTs) on glass substrate is proposed, which has been successfully verified in a 3-mu m low-temperature polycrystalline silicon (LTPS) process. The experimental results have shown that the probability in the bit stream of the digital output from the delta-sigma modulator is correctly fit in the analog input voltage ratio. Such a bit stream can be converted into 8-bit digital code successfully under the operation voltage of 10V with thin film transistors (TFTs) on the glass substrate. The proposed delta-sigma AID converter can be further used to achieve the precise analog circuits for System-on-Panel (SOP) or System-on-Glass (SOG) applications, which enables the analog circuits to be integrated in the active matrix LCD (AMLCD) panels.
Digital-to-analog converter with gamma correction on glass substrate for TFT-panel applications
(2009-10-01)
Wang, Tzu-Ming
;
Li, Yu-Hsuan
;
Ker, Ming-Dou
;
電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
Low-temperature polysilicon (LTPS) technology has a tendency towards integrating all circuits on glass substrate. However, the poly-Si TFTs suffered poor uniformity with large variations in the device characteristics due to a narrow laser process window for producing large-grained poly-Si TFTs. The device variation is a serious problem for circuit realization on the LCD panel, so how to design reliable on-panel circuits is a challenge for system-on-panel (SOP) applications. In this work, a 6-bit R-string digital-to-analog converter (DAC) with gamma correction on glass substrate for TFT-panel applications is proposed. The proposed circuit, which is composed of a folded R-string circuit, a segmented digital decoder, and reordering of the decoding circuit, has been designed and fabricated in a 3-mu m LTPS technology. The area of the new proposed DAC circuit is effectively reduced to about one-sixth compared to that of the conventional circuit for the same LTPS process.
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.