一种小信号放大测量电路的设计

Design of the measurement circuit about weak-signal amplifying

针对在恶劣工作环境中微弱信号无法准确测量的情况,设计了一种以高精度仪表放大器AD623为核心器件的放大测量电路,实现了对0m V^25m V范围内电压信号的精准放大,同时采用高精度光隔离器ACPLC87B,隔离测量端对采集端的影响。经试验测量,该小信号放大测量电路能达到百分之一精度,此外该电路还具有抑制共模干扰、抑制温漂、稳定性好、抗干扰性强等特点。

In view of the fact that weak signals cannot be accurately measured in the poor working environment, this paper proposed an amplifying measurement circuit which had the high-precision instrumental amplifier AD623 as the core device.This design could accurately amplify the voltage signals ranging from 0mV to 25mV and it also adopted a high-precision optical isolator ACPL-C87B to isolate the effect of the measuring end on the collection end.Through practical tests, it was verified that the weak-signal amplifying measurement circuit could achieve the accuracy of one percent and it also had the characteristics of suppressing common mode interference, suppressing temperature drifting, good stability and strong anti-interference.