基于差分翻转电压跟随器的AB类缓冲器设计

Design of Class AB Buffer Based on Differential Flipped Voltage Follower

为了解决传统电压缓冲器建立时间较长、功耗较大等问题,提出了一种基于差分翻转电压跟随器(Differential Flipped Voltage Follower,DFVF)的AB类缓冲放大器。电路主要由作为输入级的DFVF和基于反相器的输出级组成。与其他缓冲器相比,该电路结构简单,晶体管数量少。由于使用了AB类的缓冲器,因此输出电流不受偏置电流的影响,并且静态电流小。采用SMIC 0.18μm工艺对电路进行仿真,仿真结果表明在1.8 V电源电压、全电压摆幅下,能在0.56μs的建立时间内驱动1 n F的电容负载,同时静态电流只有5μA,可用于液晶显示器的列驱动。

A class AB buffer amplifier based on differential flipped voltage follower(DFVF)is proposed to solve the problems of long setup time and large power consumption of traditional voltage buffer.The circuit consists of a DFVF as the input stage and an output stage based on an inverter.Compared with other buffers,the circuit has simple structure and fewer transistors.Due to the use of class AB buffer,the output current is not affected by the bias current,and the static current is small.The circuit is simulated in a SMIC 0.18μm process.The simulation results show that under 1.8 V supply voltage and full voltage swing,1 n F capacitive load can be driven in the setup time of 0.56μs,and the static current is only 5μA,which can be used for column driver of liquid crystal display.