一种用于角度传感器中的仪表放大器

Instrumentation Amplifier Used in Angle Sensor

主要设计了一种用于角度传感器系统中的仪表放大器。为了满足角度传感器系统中对信号频率的要求,需要仪表放大器的带宽足够宽能够达到3.3 MHz。该电路采用标准三运算放大器结构电路,以折叠共源共栅结构的放大器为基础,对共模信号进行抑制,对差分信号进行放大,提高了放大器的精度,增大了仪表放大器的带宽。采用Chartered 0.35μm CMOS双栅工艺对电路进行仿真和流片验证,测试结果表明:在0.8～2.85 V内,仪表放大器的共模抑制比达到了102 dB,带宽能够达到3.3 MHz,输出摆幅为1.7 V,电路功能良好,达到了设计要求,该电路可用于汽车电子以及医疗设备系统。

The instrumentation amplifier for an angle sensor system was presented. The bandwidth of instrumentation amplifier should be high enough up to 3.3 MHz in order to meet the requirements of signal frequency of angle sensor. This instrumentation amplifier employs the traditional three operational amplifiers configuration and based on the folded-cascode amplifier which achieves common-mode rejection, amplifies differential signal. These have greatly enhanced the accuracy of amplifier and increased the bandwidth. The design and measured results were presented. The instrumentation amplifier was simulated and fabricated in Chartered 0. 35μm CMOS dual gate process. In the range from 0. 8 to 2. 85 V, CMRR can reach 102 dB, bandwidth is 3.3 MHz and the output swing is 1.7 V. The circuits function is well. The measured results show that the instrumentation amplifier can meet the demand of angle sensor. The instrumentation amplifier can be applied in automobile electronic and medical equipment systems.