(1. 电子科技大学 电子薄膜与集成器件国家重点实验室, 成都 610054;2. 电子科技大学广东电子信息工程研究院, 广东 东莞 523808)
范佳航(1999—),男(汉族),河北人,硕士研究生,研究方向为模拟集成电路设计。 罗 萍(1968—),女(汉族),四川人,教授,博士生导师,研究方向为智能功率集成电路与系统。通信作者。
(1. State Key Lab. of Elec. Thin Films and Integr. Dev., Univ. of Electronic Science and Technology of China, Chengdu 610054, P. R. China; 2 . Institute of Electronic and Information Engineering of UESTC in Guangdong, Dongguan, Guangdong 523808, P. R. China)
介绍了一种采用0.18 μm CMOS工艺制作的动态范围达71 dB、步长为1 dB的低噪声可编程增益放大器。为了克服传统的三运放仪表放大器共模输入范围受限的缺点,本设计采用了电流模架构,实现轨到轨的共模输入范围。内部运放采用斩波来减小其失调电压和低频1/f噪声。增益控制由粗调级和精调级两部分来实现,粗调级将电压信号转换为电流信号,精调级将电流信号恢复为电压信号,最终实现宽范围和高精度。仿真结果表明,该设计总共实现了-3 dB~68 dB的增益范围和1 dB的步长；在48 dB增益下1 Hz到100 kHz的等效输入噪声为3.573 μV,1 kHz处CMRR和PSRR分别为118.9 dB和120.6 dB。
A 71-dB-dynamic range, 1-dB-step, low-noise programmable gain amplifier based on 0.18 μm CMOS process was presented. The current model architecture was adopted to achieve R2R common mode input range(CMIR), considering the constrained CMIR of traditional instrument amplifier with three opamps. The internal opamps’ offset voltage and low-frequency 1/f noise were reduced by chopper. The control of gain was achieved by coarse adjustment and fine adjustment, the voltage signal was converted into current signal by coarse adjustment, and the fine adjustment restored the current signal to voltage signal basing on the coarse adjustment, finally wide range and high precision were realized. The simulation results showed that the gain range of -3 dB-68 dB and step of 1 dB were totally obtained; the equivalent input noise from 1 Hz to 100 kHz at 48 dB was 3.573 μV, CMRR and PSRR at 1 kHz were 118.9 dB and 120.6 dB respectively.