微伏级直流电压信号放大电路设计

摘要

针对微伏级直流电压信号测量过程中存在信噪比低、测量精度不高和抗干扰能力差的问题,设计一种以TLC2652为核心器件的放大测量电路,实现了对5～45 μV范围内电压信号的精准放大.电路采用低通滤波电路、陷波电路降低内部噪声与外部干扰;采用隔离电路,隔离测量端对采集端的影响;采用线性稳压芯片进行电源模块的设计,提高测量精度并降低功耗.经仿真实验验证,说明所设计的微伏级直流电压信号放大电路具有抑制共模干扰、抑制温漂、稳定性好、抗干扰性强等特点,测量精度达到0.044％.%In view of the facts that the low signal-to-noise ratio,poor anti-interference ability and low measurement accuracy exist in the measuring process of microvolt-level DC voltage signal,an amplifying measurement circuit taking TLC2652 as its core device is proposed in this paper to realize precision amplification of voltage signals (5～45 μV).The low-pass filtering circuit and band-stop circuit are adopted to reduce its internal noise and external interference.The isolation circuit is adopted to isolate the effect of the measuring end on the collection end.The linear regulating chip is used in power module design to improve the measurement accuracy and reduce power consumption.The simulation experiment result proves that the amplifying measurement circuit for microvoh-level DC voltage signal can suppress common mode interference and temperature drifting,has good stability and strong anti-interference,and its accuracy can reach to 0.044％.