基于传感器微弱电流矢量检测电路的设计

Design of the Weak Current Vector Measurement Based on Sensors

该文通过对锁相放大电路设计原理和相敏检波相关性原理的研究,针对当前微/纳传感器信号小、频率高、测量难的特点,采用了双相锁相放大技术,克服了目前仪器昂贵、体积大和芯片不能直接测试电流的缺点,设计了能够应用于传感器微弱电流矢量检测的电路。该电路具有小型、简单、无需调相的特点,电流测量范围:0.61nA^50nA,频带:20kHz^40kHz,阈值为0.61nA,测量精度为0.19nA,相位测量精度为0.89°,能够实现ZnO纳米线传感器微弱电流幅值和相位测量的要求。

In this paper micro/nano sensor signal is generally weak,high frequency characteristics and difficult to be measured,It is meaningful to use the dual-phase locked-in amplifier circuit for weak signal vector measurement in sensor.The paper presents a design of a miniature dual phase lock-in amplifier circuit based on the principle of phase-sensitive detection.The circuit overcome the disadvantages the price and space of instrument,and chip not measuring current.The circuit has the characters of small size,easy to operate,and no need for phase adjustment.The detectable signal range is 0.61～50nA,the frequency band is from 20kHz to 40kHz,the threshold hold value is 0.61nA,the measurement accuracy of signal is 0.19nA,and the phase measurement accuracy is 0.89°,all of which meet the requirements for detecting the weak current signal amplitude and phase of the micro/nano ZnO sensors.