Research on LCR Impedance Measurement Based on SOPC

In this paper LCR impedence measurement based on SOPC is introduced in detail. The measurement circuit is functionally divided into following three sections: The signal source section generates the test signal based on NCO in SOPC of Altera´s FPGA-Cyclone-II EP2C8.The frequency of the test signal is variable from 30 Hz to 1 MHz; The vector ratio detector section measures two vector voltages across the DUT (Edut) and range resistor Rr (Err) series circuit. Each vector voltage is separated into 0deg and 90deg parts using phase detector and measured using an A to D converter by multi-integration.The software is developed under the Altera´s development environment qartusll 7.0 and NIOS II in FPGA. In this paper, A series adjusting measures is adopted. All these measures make the entire instrument measurement accuracy 0.25%.