A Study on the Optimum Design of the Charge Pump PLL with Multi-PFD

다중 위상검출기를 갖는 전하 펌프 PLL의 최적 설계에 관한 연구

In this paper, we propose a charge pump phase-locked loop (PLL) with multi-PFD which is composed of a sequential phase frequency detector(PFD) and a precharge PFD. When the Phase difference is within - $\pi$ ∼ $\pi$ , operation frequency can be increased by using precharge PFD. When the phase difference is larger than │ $\pi$ │, acquisition time can be shorten by the additional control circuit with increased charge pump current. Therefore a high frequency operation, a fast acquisition and an unlimited error detection range can be achieved.