SEMICONDUCTOR INTEGRATED CIRCUIT

摘要

PROBLEM TO BE SOLVED: To reduce peak component of an electromagnetic radiation noise more effectively in a semiconductor integrated circuit which applies a system for reducing the electromagnetic radiation noise by dispersing a spectrum of a clock signal.

SOLUTION: The semiconductor circuit for reducing the electromagnetic radiation noise by modulating a frequency of the clock signal is equipped with: a first modulation circuit 10 for generating a first modulation clock signal having first modulation width by modulating the frequency of the clock signal having a specified frequency; and a second modulation circuit 20 for generating a second modulation clock signal having second modulation width larger than the first modulation width by further modulating the frequency of the first modulation clock signal.

COPYRIGHT: (C)2007,JPO&INPIT