一种用于LCD驱动的低功耗输出缓冲放大器

Low-Power Buffer Amplifier for LCD Driver

在AB类输出级的基础上,结合正反馈辅助的B类输出级,提出了一种用于LCD驱动电路的大输出摆率、低功耗的输出缓冲放大器。在0.15μm高压CMOS工艺模型下,该放大器能够驱动0～20nF范围的容性负载,静态电流为7μA,1%精度建立时间小于6μs,满足了LCD驱动电路行建立时间的要求;通过采用共源共栅频率补偿结合输出零点补偿技术,较好地满足了大动态范围容性负载的要求。

A high driving capability CMOS buffer amplifier with high slew-rate,low power consumption is proposed. Low power and high driving capability are achieved by using a Class AB push-pull stage and two Class B auxiliary stages with positive feedback. The design buffer amplifier draws 7 μA static current and the setting time to 1% precision is less than 6 μs under a 0~20 nF capacitance load with a 0.15 μm CMOS model,which satisfies the setting time requirement of LCD driving circuit; By using cascoded frequency compensation combined with zero formed with the capacitive loads,large dynamic range of capacitive loads is satisfied.