摘要
设计了一种CMOS恒跨导轨对轨输入/输出运算放大器,输入级采用负反馈技术控制尾电流,能自调整gm并使之保持恒定;输出级采用前向偏置AB类输出结构,实现轨对轨输出的同时减小了静态功耗。整个电路在5 V电源电压下,电压增益达到136 dB(1 MΩ电阻和1 pF电容并联负载),单位增益带宽为9.7 MHz,相位裕度62.4°。
A CMOS operational amplifier with rail - to - rail input/output ranges and constant - gm is presented. Feedback technique is implemented to control tail current, ensuring self- adjusting gm at a constant value. Class AB output stage is adopted to guarantee full rail -to -rail performance and low quiescent dissipation. At 5 V power supply, the voltage gain of this opamp is 136 dB （loaded by 1 MΩ resistor shunted with 1 pF capacitor） ,meanwhile unit gain bandwidth is 9.7 MHz,phase margin is 62.4°.
出处
《现代电子技术》
2007年第12期41-44,48,共5页
Modern Electronics Technique
关键词
恒跨导
轨对轨输入输出
负反馈
运算放大器
constant -gm
rail - to - rail input/output
feedback
operational amplifier
