Abstract: A two-stage driving circuit of a one-chip TFT-LCD driver IC for portable electronic devices is proposed.The driving buffers of the new circuit are built in the γ-correction circuit rather than in the source driver.The power consumption,die area,and driving capability of the driving circuit are discussed in detail.For a two-stage driving circuit with 13 driving buffers,the settling time of the driving voltage within 0.2% error is about 19.2μs when 396 pixel-loads are driven by the same grayscale voltage.The quiescent current of the whole driving circuit is 518μA,and the power consumption can be reduced by 77%.The proposed driving circuit is successfully applied in a 132RGB×176-dot,260k color one-chip driver IC developed by us for the TFT-LCD of mobile phone,and it can also be used in other portable electronic devices, such as PDAs and digital cameras.

Key words: TFT-LCD, source driver, γ-correction, grayscale voltage