Background: Signal generator plays crucial role in the field of automatic measurement. However, Domestic signal generator usually uses a number of discrete phase locked loop components, whose circuits are usually complex with low precision and are easy to be affected by the external environment.
Objective: Based on direct digital synthesis (DDS) technology, a small sized high precision economic waveform generator with simple structure and operational convenience is developed.
Methodology: The hardware circuit is designed with an AT89S52 controller, and the corresponding peripheral circuit. A DDS integrated chip AD9834 is employed as the signal source, and the modular programming principle with C and assembly language is used to accomplish the software design, where the sine wave, square wave, triangular wave signals with adjustable amplitude, frequency, and TTL signal with adjustable duty ratio can be generated.
Conclusion: The whole system is advantageous on several aspects such as high frequency precision, wide frequency range, and operational convenience. The experimental results show that the stability and reliability of the waveform generator are good with a simple hardware circuit structure.