Design and Implementation of DDS Signal Generator Based on FPGA

Abstract

With the rapid development of semiconductor technology, the digital circuit of the control chip gradually replaces the analog circuit of the traditional signal generator, which improves the performance of the signal generator and reduces the cost of research, development and production. This paper proposes a design scheme that takes FPGA chip as the control center. The signal generator system mainly includes DAC module, FPGA module and key module. The system uses Verilog language to develop the sine wave digital signal generation and key switching frequency control logic circuit on FPGA. The frequency control word circuit in the FPGA module provides multiple frequency sine wave selection, and the look-up table circuit realizes the reading of different phases by controlling the read address of the ROM. The 14-bit high-speed DAC module converts the digital signals sent by FPGA into analog signals. The DAC module integrates low-pass filter processing to increase the smoothness of the signal. After testing, the system meets the design requirements.