A noval fast-locking ADPLL based on Newton's Method

Based on the idea of Newton's Method, a new structure of AllDigital Phased-Locked Loop(ADPLL) is proposed. The ADPLL is made up of a fully customized frequency comparator, controller and digital-controlled oscillator (DCO). The proposed structure and locking method are different from the traditional one. RTL simulation results show that the lockin time of the proposed ADPLL with 2 different output frequenciesis, is much faster than the traditional structure, only N reference clock cycle, saving at least 86%.