摘要
在采用矢量电流电压法测量阻抗时,目前大多采用两种方法来实现阻抗矢量虚实部的分离。一种是通过相敏检波器来实现,另一种是通过高速ADC采样信号,通过比较零点位置获取相位差信息来实现。前一种方法实现复杂且测量速度不易提高,后面的一种测量方法成本太高。本文主要介绍将TDC芯片应用于经典的电流电压法阻抗测量中,用TDC芯片获取被测信号的相位差信息,从而实现复阻抗实部与虚部分离的新方法,在降低成本的同时实现高精度LCR参数测量。
When using Current-Voltage method to measure the impedance,we often have two methods to depart it into real part and imaginary part.One is using phase detector,and the other is by finding and comparing the zerocrossing point of samples of ADC to obtain the phase information between the reference signal and measured signal.The former is complex and hard to get the quick testing speed,and the latter costs too much.So,we put forward a new method to obtain the phase information.In this article,TDC is applied to the classic Current-Voltage method to measure impedance,whose usage is for obtaining accurate phase information to separate the real part and imaginary part of complex impedance.The application of TDC chip in impedance measurement can achieve higher accuracy LCR parameters testing and reduce the cost at the same time.
出处
《电子测试》
2012年第1期62-65,共4页
Electronic Test
