Design of Charge Signal Generator Based on DDS Technology

The charge signal generator was designed by using Field Programmable Logic Gate Array(FPGA), Digital to Analog Conversion (DAC) circuit and charge conversion circuit. The Direct Digital Frequency Synthesis (DDS) was used to realize the frequency modulation, amplitude modulation and phase modulation of the signal. At the same time, the operating principle of the DDS technology and the design ideas of the analog circuit were described in detail. Under the Modelsim software platform, the function simulation of the program was carried out, and the real-time signal was captured and displayed by the SignalTap II logic analyzer. The correctness of the program was proved by the simulation results and the actual waveform. The voltage signal was converted into the charge signal, and joint debugging with the charge converter and the conditioning amplifier. Tests showed that the output waveform can meet the design specification and this proves the validity and reliability of the charge signal generator. The charge signal generator can be used as a standard signal source for the installation and commissioning of loose parts and vibration monitoring system, and it can be used for overhaul inspection of nuclear power stations.