A DSP-based LCR meter design
Jiansen Ma, Bin Wei, Hengyi Liu, Tao Liu · 2024
The system is based on the principle of balanced bridge four-wire measurement, with TI's C2000 series TMS320F28379D processor as the core, The system uses DDS to generate a sinusoidal excitation signal of the bridge measurement circuit, the measured inductance or capacitance through the four-wire test folder access to the automatic balance bridge, DSP on-chip ADC bridge signal for dual-channel synchronous sampling, access to the device under test voltage, current vector signal discrete sequence; and then use the DSP's outstanding digital signal arithmetic capabilities, through the FFT operation to get the amplitude of the voltage and current signals, phase information, and then calculate the capacitance of the capacitor, the value of the D value, or inductance of the sense of the value of the Q value. Test results show that this system the device is calibrated with the instrument, the error are within 3%.