Patent ID: 7613254
Filing Date: 2009-11-03
Classification: H03D

Abstract:
1. A phase detector that compares the phases of data and four-phase first, second, third, and fourth clocks having a half rate of the data and being out of phase with one another by a specified value, the phase detector comprising: first, second, third, and fourth sampling circuits that sample the data according to the four-phase first, second, third, and fourth clocks; a first comparator that compares first and second sampling data obtained by sampling according to the adjacent two-phase first and second clocks using the first and second sampling circuits, respectively, to each other, and when the first and second sampling data are different from each other, outputs a first up signal; a second comparator that compares fourth sampling data and the first sampling data obtained by sampling according to the adjacent two-phase fourth and first clocks using the fourth and first sampling circuits, respectively, to each other, and when the fourth and first sampling data are different from each other, outputs a first down signal; a third comparator that compares the second sampling data with a third sampling data obtained by sampling according to the adjacent two-phase second and third clocks using the second and third sampling circuits, respectively, and when the second and third sampling data are different from each other, outputs a second down signal; and a fourth comparator that compares the third sampling data with a fourth sampling data obtained by sampling according to the adjacent two-phase third and fourth clocks using the third and fourth sampling circuits, respectively, and when the third and fourth sampling data are different from each other, outputs a second up signal.