Patent ID: 8378725
Filing Date: 2013-02-19
Classification: H03L

Abstract:
1. A phase-locked loop (PLL), comprising: a voltage-controlled oscillator (VCO), including: a phase detector, connected to the VCO, for generating an error signal based on an input reference signal and a fraction of the oscillator signal; a current mirror circuit, connected to the voltage-to-current converter, for generating a second current based on a fraction of the first current; a dual charge pump circuit connected between the phase detector and the voltage-to-current converter, for receiving the error signal and the second current, and generating first and second charge pump currents according to a predetermined ratio; and an active loop filter connected to the dual charge pump circuit, the current mirror circuit and the voltage-to-current converter, wherein the active loop filter generates the control voltage based on the first and second charge pump currents, and wherein the active loop filter includes: