Multi-phase realigned voltage-controlled oscillator and phase-locked loop incorporating the same

Abstract

A multi-phase realigned voltage-controlled oscillator (MRVCO) achieves phase realignment based on charge injection in the VCO stages with the injection amount proportional to the instantaneous phase error between the VCO output clock and a reference clock. The MRVCO may be incorporated as part of an implementation of a multi-phase realigned phase-locked loop (MRPLL). A separate phase detector, as well as a specific realignment charge pump, may be provided in the PLL for controlling the VCO. The VCO has lower phase modulation noise, so that the PLL has very large equivalent bandwidth.