Influence of the IC power supply and decoupling capacitor arrangement on the electromagnetic emission

Abstract

With the advancing development of integrated circuits (ICs), more and more complex functions and higher performance levels can nowadays directly be integrated into a single IC package. In this context, the issue of electromagnetic compatibility (EMC) is becoming more critical, as the higher the integration density, the higher the electromagnetic emissions tend to be. In this paper, an EMC test IC is used to investigate the influence of different power supply pinouts (arrangement of VDD and GND pins in center and corner configuration) on the electromagnetic emission of the IC. This is done on the basis of the surface-scanning technique described in the IEC 61967‑3 standard for characterizing the magnetic near field at the surface of the IC package, and on the basis of the 150 Ohm measurement method described in IEC 61967‑4 for determining the conducted interference emissions at the power supply pinout of the IC. Both measurement methods show a significant difference in electromagnetic emissions due to the dependence on the arrangement of the power supply pinouts. These results highlight the importance of careful power supply design in the development of electromagnetically compatible ICs.