舱室有毒有害气体检测前置放大电路设计  

The Design of Preamplifier Circuit for Toxic and Harmful Gas Detection in Cabin

作　　者：李明勇 LI Mingyong(CSSC AlphaPec Instrument(Hubei)Co.,Ltd.,Yichang Hubei 443003,China)

机构地区：[1]中船重工安谱(湖北)仪器有限公司,湖北宜昌443003

出　　处：《电子器件》2023年第4期901-905,共5页Chinese Journal of Electron Devices

基　　金：测试仪器领域第一批工程项目(2006ZCTJ0017)。

摘　　要：针对低浓度舱室有毒有害气体传感信号微弱的问题,在传统的电阻反馈型和电容积分型前置放大电路基础上,提出了一种新型前置放大电路设计方法。该方法结合了电阻放大和电容放大的优点,采用反馈补偿的方式,将输出信号的直流成分反馈至输入,补偿掉输入信号直流成分,在减小电阻放大型电路热噪声大的同时又避免了电容积分型电路容易饱和的问题。通过和德国FEMTO公司溯源级前置放大器DLPCA-200在增益、带宽和噪声方面的对比表明,新型前置放大电路性能略优于DLPCA-200,其跨阻增益可达1010,带宽≥10 kHz,能够提升舱室有毒有害气体信号的信噪比,进而提升检测灵敏度。Aiming at the problem of weak sensor signal of low-concentration toxic and harmful gas in cabin,a new preamplifier circuit design method based on the traditional resistive feedback and capacitive integral preamplifier circuits is proposed.The method combines the advantages of resistance amplification and capacitance amplification.The input DC part is compensated by the feedback of the DC part of output signal to input.The new preamplifier circuit not only reduces thermal noise but also avoids the problem that the capacitor integral circuit is easy to saturate.Results of comparison in gain,bandwidth and noise with the German FEMTO preamplifier DLPCA-200 show that the performance of the new preamplifier circuit is better than that of DLPCA-200.The TIA of circuit reaches 1010 and the bandwidth of the circuit is more than 10 kHz.Besides,the SNR of the toxic and harmful gas signals in the cabin is improved and the detection sensitivity is also improved.

关 键 词：有毒有害气体检测 前置放大电路 噪声 带宽扩展 反馈补偿 

分 类 号：TH89[机械工程—仪器科学与技术]