Design And Simulation Of All Digital Phase-locked Loop Circuits Structure Based On Digital Pi Regulation

Since the Phase-Locked Loop (PLL) technology has been widely used in radio ,TV, communications and industrial automation fields, the PLL circuit has become essential component in high-quality electronic equipments and systems. The emergence of the all digital PLL(ADPLL) has greatly improved the PLL's performance, such as its anti-interference, high-density integration and simple external interface circuits. In ADPLL system, every part is designed and implemented by using of digital logic components. In this paper, a new structure scheme of ADPLL system based on digital proportional integral (PI)regulation has been proposed. This main reseach work is as follows:Firstly, with careful analysis and comparison of traditional phase-locked loop system structure, a new structure scheme of ADPLL system based on digital proportional integral (PI)regulation is proposed .Secondly, key components of ADPLL system have been designed ,simulated and implemented by using of EDA tools and FPGA/CPLD circuits.Finally, the whole ADPLL system has been designed ,simulated and implemented by using of Top-Down method .Theoretical analysis and experimental simulation results show that the design of ADPLL is characterized with better system stability, quicker locking speed , wider tracking range and more flexible controlling.