摘要 |
A clock signal extracting circuit extracting a clock signal from N-pieces of data bit signals, where said N is an integer of two or more, including N-pieces of phase comparators, each of which compares a phase of each of the data bit signals with a phase of an extracted clock signal and generates a up-signal and a down-signal in accordance with a compared result, N-pieces of charge pumps, each of which generates a current in accordance with the up-signal and the down-signal inputted from each phase comparator, an adder for adding currents generated by the N-pieces of charge pumps, a loop filter for generating a control voltage in accordance with an added current by the adder, and a voltage control oscillator for generating the extracted clock signal of a frequency in accordance with control voltage. With this configuration, it is possible to prevent a retiming margin in a parallel digital interface from increasing. |