CIRCUIT FOR REDUCING AN ELECTROMAGNETIC INTERFERENCE, ESPECIALLY IN ORDER TO REDUCE AN ELECTROMAGNETIC INTERFERENCE PHENOMENON CAUSED BY AN INCREASE OF CLOCK FREQUENCIES IN AN LCD MODULE

摘要

PURPOSE: A circuit for reducing an electromagnetic interference is provided to control capacitance of a capacitor connected to an input terminal of a differentiator, to change a range of a permissible frequency, thereby obtaining an electromagnetic interference reducing effect in a desired frequency band. CONSTITUTION: A differentiator(10) includes a capacitor(C), and differentiates a clock signal(HCLK). An inverter(20) inverts an output signal of the differentiator(10). A noninverting adder(30) adds an output signal of the inverter(20) to components of the clock signal(HCLK). A permissible frequency range of the differentiator(10) is controlled by the capacitor(C) included in the differentiator(10).