基于DDS的可程控高精度LCR测试仪

Programmable Controlled High Precision LCR Tester Based on DDS

为了提高测量电感、电容、电阻的精度,设计了一种基于直接数字频率合成DDS的可程控高精度LCR测试仪。该测试仪采用阻抗-相角法结合填充计数法来分别测量各参数;其FPGA芯片则采用DDS技术,产生高频率、高精度和高幅值稳定度的正弦波激励信号;同时,该测试仪还设计了用来实现仪器可程控的接口模块。仿真结果表明,该测试仪大大提高了电感、电容、电阻等参数的测量精度,取得了很好的测量效果。

In order to enhance the measurement accuracy for parameters of inductance, capacitance and resistance, a highly precise program- mable controlled LCR tester based on direct digital frequency synthesis（DDS） is designed. The tester is using impedance-phase angle method and combining with the fill-up counting method to measure L, C and R respectively. The high frequency sine wave, whose frequency is high and whose amplitude is stable, is created by the FPGA chip in the tester, and used as the energizing signal of the instrument. The tester also features programmable control by using the interfacing module. The simulation indicates that the instrument greatly enhances the measurement accuracy for parameters of L, C and R, and gets better measuring effects.