EMI COUNTERMEASURE CIRCUIT AND EMI COUNTERMEASURE METHOD USED FOR THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an EMI countermeasure circuit that has large reduction effect on a disturbing wave and can reduce influence on a clock transmitted through a clock wiring and adjust the reduction effect on the disturbing wave according to the transmission state of the clock wiring and an EMI countermeasure wiring.;SOLUTION: A clock from an oscillation part 1 is inputted to an N-multiplier 3 which multiplies the clock by 1 to N (N: natural number). The clock outputted from the N-multiplier 3 is inputted to a phase shifter 4 which shifts its phase by 0 to 360°. The clock outputted from the phase shifter 4 is inputted to a filter 5 which passes only a necessary frequency band. The clock outputted from the filter 5 is inputted to a gain control part 6 and adjusted there to a necessary amplitude. The clock outputted from the gain control part 6 is inputted to an EMI countermeasure wiring 101 wired in parallel to a clock wire 100 connecting the oscillation part 1 and a clock transmission object 2 together and then transmitted to a terminal part 9 through the EMI countermeasure wiring 101.;COPYRIGHT: (C)2004,JPO