Phase lock loop

摘要

A very fast lock integer N PLL with hybrid digital coarse VCO tuning and VCO temperature drift compensation provides for a fully digital tuning scheme without the need for charge pumps. A PLL synthesizer (300) using such a PLL design provides for very fast lock times by using an open loop step and a closed loop step. The hybrid PLL can achieve coarse tuning within four clock cycles, while minimizing any errors caused by the VCO non-linearity. Temperature tracking and compensation is also provided. A SAR implementation (100) and an interpolation tuning implementation (200) are also described.