Patent ID: 7659759

Claim:
A phase synchronous circuit comprising first, second, and third selectors, first, second, and third delay arrays, first, second, and third selector control circuits, a distribution circuit, a synthesizing circuit, a phase comparator array, and first and second output signal control circuits, wherein the first selector has a first input that receives a first reference clock, and a second input connected to an output of the first delay array, and which input from among the first and second inputs to be outputted is selected by the first selector control circuit, wherein the first delay array has an input connected to the output of the first selector, and an output connected to the second input of the first selector, wherein the phase comparator array receives a second reference clock and an output group from at least one delay stage of the first delay array as input, and outputs a comparison result of the phases between these inputs to the first output signal control circuit, wherein the distribution circuit distributes an external clock for output of first and second distributed external clocks to the second selector and the third selector, respectively, wherein the second selector has a first input that receives the first distributed external clock, and a second input connected to an output of the second delay array, and which signal from among the first and second inputs to be outputted is selected by the second selector control circuit, wherein the second delay array has an input connected to the output of the second selector, and an output connected to the second input of the second selector, wherein the first output signal control circuit selects at least one of the outputs from the second delay array by using the comparison result from the phase comparator array, and outputs the selected signal after the first distributed external clock round-trips the second selector and the second delay array plural times, wherein the third selector has a first input that receives the second distributed external clock, and a second input connected with an output of the third delay array, and which signal from among the inputs to be outputted is selected by the third selector control circuit, wherein the third delay array has an input connected to the output of the third selector, and an output connected to the second input of the third selector, wherein the second output signal control circuit selects at least one of the outputs from the third delay array by using the comparison result from the phase comparator array, and outputs the selected signal after the second distributed external clock round-trips the third selector and the third delay array plural times, and wherein the synthesizing circuit synthesizes the outputs of the first and second output signal control circuits for output.