Patent ID: 7489743
Filing Date: 2009-02-10
Classification: H03L,H04L

Abstract:
1. A recovery circuit comprising: a phase detector configured to compare a phase of input data with a phase of a current output clock to generate a first up signal and a first down signal, a quadrant decision unit configured to determine a phase location for the current output clock and output quadrant decision signals based on a voltage difference between first and second phase control voltages, a quadrant controller configured to output a second up signal and a second down signal based on the first up signal and the first down signal and the quadrant decision signals, a charge pump unit configured to output the first and second phase control voltages based on the second up signal and the second down signal, and a phase interpolator configured to select clocks from a plurality of clocks based on the quadrant decision signals and output an output clock based on the selected clocks and the first and second phase control voltages.