The Design and Implementation of a Signal Source for EIT System Using DSP Builder

A signal source for EIT system is designed and realized in this paper. Firstly, a brief introduction and some theoretical analysis are made about the basic principles of Direct Digital Synthesizer, DDS. Then a DDS module based on DSP Builder is built, according to the performance requirement of the hardware circuit of EIT system. Simulations and verification of the built DDS module is carried out and results shows that the performance of the DDS signal source is in the accord with the actual requirement of EIT system. The DDS error is also analyzed to assure the correctness of the design. Finally, the method of realizing the signal source is given to accomplish DDS on the EP2C35F672C6, one of the cyclone series FPGA chips supplied by Altera Corporation.