The effect of decoupling capacitor distance on printed circuit boards using both frequency and time domain analysis

Abstract

This paper demonstrates the effect of decoupling capacitor distance on the amount of EMI noise created at an IC's power pin. As the distance is increased, the amplitude of the noise is increased if the capacitor has been attached to the printed circuit board (PCB) with a low inductance connection. This effect is most apparent when the dielectric thickness of the PCB is greater. Furthermore, this paper demonstrates the need to do this type of analysis in the time domain and not the frequency domain