An output buffer with slew-rate calibration for different TFT-LCD loadings

An output buffer with slew-rate calibration for different TFT-LCD loadings is presented. Unlike other output buffers of column drivers, the proposed output buffer adjusts the output current according to the loading capacitors. The settling time and slew-rate of the proposed output buffer are thus fixed in an acceptable range for different TFT-LCD loading capacitors, allowing more accurate color quality. The proposed output buffer amplifier is implemented on standard 0.35 μm CMOS 2-poly 4-metal process technology and simulated using HSPICE. The settling time of rising and falling for 10kΩ+50pF~10kΩ+600pF are 0.45μs~1.40μs and 0.75μs ~1.84μs, respectively.