一种低失调运算放大器的设计  

Design of a Low Offset Operational Amplifier

作　　者：韩前磊 孔祥艺 施建磊 HAN Qianlei;KONG Xiangyi;SHI Jianlei(The 58th Research Institute,China Electronics Technology Group Corp,Wuxi Jiangsu 214035,China)

机构地区：[1]中国电子科技集团公司第五十八研究所,江苏无锡214035

出　　处：《电子器件》2022年第6期1312-1316,共5页Chinese Journal of Electron Devices

摘　　要：基于Bipolar工艺设计,结合激光修调技术,实现了一种四通道、低失调、低功耗、高增益的运算放大器。电路整体结构包含基准偏置电路、差分输入及偏置补偿电路、中间级电路、输出及过流保护电路。输入级选择差分输入结构,采用输入偏置补偿设计,降低了输入失调电压和偏置电流;中间级采用射随器结构,结合密勒补偿电容及零点电阻,提高电路的稳定性;输出级采用B类的输出结构,结合过流保护设计,增加电路的安全性。电路封装后测试显示:输入失调电压为10μV,输入偏置电流为0.5 nA,大信号电压增益为130 dB,电源电流为2.4 mA,增益带宽积为1.5 MHz,电压噪声密度为7.34 nV/√Hz。Based on the Bipolar process design,combined with laser trimming technology,an operational amplifier with low offset,low power consumption and high gain is realized.The overall structure of the circuit includes a reference bias circuit,a differential input and bias compensation circuit,an intermediate circuit,and output and overcurrent protection circuit.The differential input structure is selected and the input offset compensation design is adopted for the input stage,which reduces the input offset voltage and bias current.The emitter follower structure is adopted for the intermediate stage,which combines Miller compensation capacitor and zero resistance to improve the stability of the circuit.Class B output structure is adopted for the output stage,combined with overcurrent protection design,to increase the safety of the circuit.Test after circuit packaging shows that the input offset voltage is 10μV,the input bias current is 0.5 nA,the large signal voltage gain is 130 dB,the power supply current is 2.4 mA,the gain bandwidth product is 1.5 MHz,and the voltage noise density is 7.34 nV/√Hz.

关 键 词：双极型 激光修调 差分输入 低功耗 低失调 

分 类 号：TN919.3[电子电信—通信与信息系统]