INTEGRATED CIRCUIT DEVICE INCORPORATING DLL CIRCUIT

摘要

PROBLEM TO BE SOLVED: To improve the accuracy of the phase adjustment of a DLL circuit by preventing the influence of power supply noise generated by the operation of an internal circuit to the DLL circuit, so to prevent jitters from occurring.

SOLUTION: An external power supply given to the integrated circuit device is divided into first external power supplies Vcc1 and Vss1 for the DLL circuit, and second eternal power supplies Vcc2 and Vss2 for circuits other than the DLL circuit. The first external power supplies are used for the delay unit of the variable delay circuit of the DLL circuit to prevent power supply noise generated in the second external power supplies from being transmitted to the variable delay circuit. The first power supplies are used for a phase coincidence detecting part (or simply comparing part) in the phase comparator circuit of the DLL circuit to prevent the power supply noise generated in the second external power supplies from being transmitted to the phase coincidence detecting part. A first external ground power supply is given to the variable delay circuit or the phase coincidence detecting part to suppress the influence of power supply noise from a second external ground power supply based on the operations of the other circuits.

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