TFT-LCD驱动芯片的二级驱动电路

针对单芯片集成的TFT-LCD驱动芯片的特性,提出了在γ校正电路中加入两级驱动Buffef的驱动电路结构,以及提高其驱动能力的有效措施.对于具有13个驱动buffer的二级驱动电路,当由一个灰度电压驱动全部396个像素单元时,驱动电压的最大安定时间约为19.2μs;静态消耗电流为518μA,与传统的64个驱动buffer电路相比,其功耗减小了77%.本文的设计结果已成功应用于132RGB×176分辨率、26万色彩色显示手机用TFT-LCD驱动芯片中,其也可用于PDA、数码相机等其他便携电子设备的显示驱动.

Two-Stage Driving Circuit for One-Chip TFT-LCD Driver IC

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 twostage 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.