恒定跨导Rail-to-Rail CMOS运放设计

Design of a Constant Transconductance Rail-to-Rail CMOS Operational Amplifier

设计了一种新型的低电压低功耗且跨导恒定的Rail-to-Rail CMOS运算放大器,输入级采用改进的最大电流选择电路结构,输出级采用推挽输出结构,其输入输出摆幅均为Rail-to-Rail,工作电压为±1.5V.整个电路采用BSM30.5μm CMOS工艺模型参数进行了HSPICE仿真,静态功耗仅为0.5mW,当电路驱动20pF的电容负载时,电路的直流增益达到78dB,单位增益带宽达到470MHz,相位裕度为59°.

This paper presents a new low-voltage low-power, constant transconductance rail-to-rail CMOS operational amplifier. Input stage circuit uses a new maximum current selecting circuit, and output stage circuit is push-pull. In a word, the swing of the whole circuit is rail-to-rail. When driving a capacitive load of 20pF, simulation results of the proposed CFOA in BSM3＇ 0.5μm CMOS technology with HSPICE show a 78dB open loop gain, 470MHz unity gain bandwidth, 59 degree phase margin, and power consumption around 0.5mW from ± 1.5V supply voltage.