一种基于BiFET工艺的高输入阻抗运算放大器  

A High Input Impedance Operational Amplifier Based on BiFET Process

作　　者：于晓权[1] 范国亮 YU Xiaoquan;FAN Guoliang(The 24th Research Institute of China Electronics Technology Group Corporation,Chongqing 400060,P.R.China)

机构地区：[1]中国电子科技集团公司第二十四研究所,重庆400060

出　　处：《微电子学》2020年第6期784-788,共5页Microelectronics

摘　　要：针对CMOS运算放大器存在的输入失调电压高、噪声性能差等问题,提出了一种基于双极结型场效应晶体管(BiFET)工艺的高输入阻抗运算放大器。采用P沟道JFET差分对作为输入级,实现了pA量级的极低输入偏置电流/失调电流和nV/√Hz量级的极低输入噪声电压谱密度。采用双极晶体管构成的共集-共射增益级和互补推挽输出级,实现了100 dB的开环增益、10 V/μs的输出电压转换速率和10 MHz的带宽。该运算放大器适用于对微弱模拟信号的采集和放大。In order to solve the problem of high input voltage offset and poor noise performance of CMOS operational amplifiers, a high input impedance operational amplifier based on bipolar junction field effect transistor(BiFET) process was proposed. Using P channel JFET differential pair as input stage, extremely low input bias current/offset current at pA level and extremely low input noise voltage spectrum density at nV/√Hz level were realized. The common-collector common-emitter gain stage and complementary push-pull output stage composed of bipolar transistors were used to realize the open-loop gain of 100 dB, the output voltage conversion rate of 10 V/s and the bandwidth of 10 MHz. The operational amplifier was suitable for weak analog signal acquisition and amplification system.

关 键 词：运算放大器 BiFET工艺 高输入阻抗 输入偏置电流/失调电流 输入电压噪声谱密度 

分 类 号：TN722.77[电子电信—电路与系统]