A Low-Power TFT-LCD Column Driver Design for Dot-Inversion Method

Shao-Sheng YANG  Pao-Lin GUO  Tsin-Yuan CHANG  Jin-Hua HONG  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E87-A   No.2   pp.364-369
Publication Date: 2004/02/01
Online ISSN: 
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Analog Circuit Techniques and Related Topics)
TFT-LCD,  low-power,  column driver,  charge-sharing,  charge conservation,  

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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. 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.