A Low-Power Phase Compression Design Methodology on TFT-LCD Column Driver for Dot-Inversion Method

• Main Authors: Shao-Sheng Yang, 楊紹聖
• Other Authors: Tsin-Yuan Chang
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/98287586651115018406

博士 === 國立清華大學 === 電機工程學系 === 93 === A novel multi-phase charge-sharing technique is proposed for the dot inversion method to reduce AC power consumption of the TFT-LCD column driver without requiring any external capacitor for charge conservation. The Searching Algorithm discovers near-optimal configurations. After the exhaustive search, Phase Compression is also applied to reduce the time of charge conservation. For realistic consideration, the switching distance is limited to reduce the complexity of Searching Algorithm and decrease switch routing between column lines. Simple and easy-to-control circuitry is applied in the proposed method, and the power saving efficiency depends on number of charge phases. Increasing the number of charge phases, the saving power efficiency is also raised. Excluding power dissipation of switches, the power saving efficiency is up to 75% theoretically with infinite phases. For previous work, the maximum power saving efficient is 50% without external capacitor. The HSPICE simulation results including power dissipation of all switches show that the proposed method with seven charge phases (eight-column lines as one group) decreases the power consumption of 23%-68% and 10%-18%, respectively, compared with original circuit (without any low-power scheme) and previous low-power charge-recycling works.